Article

Large‐scale climatic drivers of regional winter bird population trends

Diversity and Distributions

August 2016
22(11)

DOI:10.1111/ddi.12480

Authors:

Ruud P B Foppen

Radboud University

Henning Heldbjerg

Aarhus University

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Aim Changes in climate and land use practices have been found to affect animal populations in different parts of the world. These studies have typically been conducted during the breeding season, whereas the non‐breeding season (hereafter ‘winter’) has received much less attention. Changes in regional winter abundances could be caused by changes in overall population sizes and/or redistribution of populations. We tested these mechanisms for terrestrial winter bird population changes in Northern Europe and explored the role of climate change and species habitat preference. Location The Netherlands, Denmark, Sweden, Finland. Methods We used winter bird counts from four countries conducted annually between 15 December and 20 January in 1980/1981–2013/2014. We report national population trends for 50 species for which a trend could be calculated in at least three of the countries. We analysed country‐specific population growth rates in relation to species’ climatic summer and winter niches, habitat preference and migratory behaviour. Results Species breeding in colder (typically northern) areas showed more negative winter population trends than species breeding in warmer areas. Regional winter population trends were negatively correlated with characteristics of their winter climatic niche: populations in the colder part of their winter distribution increased in abundance, whereas populations in the warmer part of their winter distribution decreased. Woodland species tended to do better than farmland species. Migratory behaviour did not explain variation in population trends. Main conclusions The generally decreasing winter population trends of cold‐dwelling breeding species probably reflect the general decline in population sizes of these species. In contrast, increasing winter population trends for populations in the colder parts of the winter distribution indicate a redistribution of wintering individuals towards the north‐east. Both these patterns are likely caused by climate change.

A comparison of two snapshot studies half a century apart suggests stability in a Pacific Northwest winter forest bird community

Article

Full-text available

Feb 2024

Populations of many North American bird species have declined throughout the past half century. The majority of studies quantifying these declines have analyzed counts of birds taken during spring and summer, not during the season of scarcity, winter. We re-surveyed seven large study plots in Douglas fir (Pseudotsuga menziesii) forests initially surveyed in winter during the late 1960s in the Oregon Coast Range, USA. We compared density estimates, observed species richness and vegetation structure within plots, and inspected aerial photography to describe changes in landscape-level landcover. To assess potential drivers of change, we reviewed historical climate data and explored patterns of abundance associated with forest age. Observed species richness was greater in the modern surveys. Abundances of four of the six most common bird species appeared to be similar to or slightly lower than 50 years ago as the historical point estimates usually fell within or above 95% confidence intervals generated from our analyses. We found no clear associations with changes in bird communities and forest structure, climate, or forest age. The historical data are unique in providing point estimates of abundance for the entire bird community on each study plot. Yet, some uncertainties in accuracy of the historic counting methods could still influence interpretation of multi-decadal changes in apparent abundance. We conclude that this Pacific Northwest bird community was relatively stable in its abundances of the most common forest-dwelling species and that largely the communities are still intact. Additional production of precisely repeatable surveys of winter bird communities are needed in all habitats to adequately characterize long-term population dynamics during the season of scarcity. KEYWORDS avian community change, winter bird communities, historical biodiversity data, biodiversity benchmarks, long-term change in bird abundance, Pacific Northwest Frontiers in Bird Science

Long-Term Changes in a Pygmy Cormorant Microcarbo pygmaeus Wintering Population in Southern Bulgaria

Article

Full-text available

Jun 2023

Waterbirds are declining globally due to different threats that affect their abundance and shift both their breeding and wintering ranges. Cormorants disperse over vast distances during winter and are suitable indicators of the impacts of human-wildlife interactions and abiotic factors. During wintering periods, Pygmy Cormorants Microcarbo pygmaeus use regular roosts where they overnight on suitable perches, a refuge from adverse weather conditions and disturbances. Our study aimed to determine the wintering population size of the Pygmy Cormorant and its dynamics across 23-years (1996–2019) at seven roosting sites in the Maritsa River valley, Southern Bulgaria. This is a critical site for the species conservation where 3065–8180 birds are wintering annually. The wintering Pygmy Cormorant population showed a tendency to increase between 1996 and 2019 (λ = 1.03 ± 0.001). Each year Pygmy Cormorants were most abundant in December (mean ± SE, 2609 ± 185 individuals), while the lowest numbers were recorded in March (1207 ± 106). Pygmy Cormorants aggregated to roost between 4:00 PM and 5:30 PM throughout the study. The area of wintering foraging habitat of the Pygmy Cormorant increased significantly across all roosting sites in the study period from 2675.97 ha to 22564.35 ha. The number of Pygmy Cormorants at the roost was positively affected by the drop in the daily air mean temperatures and the decrease of the day length. Despite the global population increase, the Pygmy Cormorant faces a high risk of human-induced mortality during wintering and is thus regionally classified as endangered.

Risico's en kansen van klimaatverandering voor de Nederlandse natuur: Invloed van temperatuurstijging, extreme droogte of natheid, zeespiegelstijging en verzilting op de doelen voor VHR, KRW, ecosysteemdiensten en algemene biodiversiteit

Technical Report

Full-text available

Mar 2024

The national and provincial governments in the Netherlands are taking many measures to achieve nature conservation objectives, such as those of the EU Birds and Habitats Directives and Water Framework Directive and for ecosystem services and biodiversity in general. Climate change can be a risk for Dutch nature. It is therefore important to obtain a good understanding of the current and future risks of changes such as rising temperatures, extreme drought, extreme wetness, sea level rise and salinisation. From a literature study and expert knowledge we conclude that the risks associated with climate change will probably increase in the future and will play a more important role in achieving the goals for nature. Climate change also presents some opportunities, but to a lesser extent.

Modeling the Dynamics of Avian Populations in Europe (1980–2019) through Generalized Additive Mixed Models

Article

Feb 2024
BIOL BULL+

The population abundance of birds is an important way to gauge the sustainability and health of the environment. However, several factors influence their distribution and density in different habitats. This paper aims to provide a comprehensive and updated outlook on bird population dynamics in Europe in the past 40 years. With the use of Generalized Additive Mixed Models (GAMMs), we analyzed the data available from the Pan-European Common Bird Monitoring Scheme (PECBMS) on abundance indexes collected throughout Europe from 1980 to 2019 and explored the driving forces behind our observed changes for each habitat type. We also apply GAMMs to model the overall changes in abundance indices of eight bird species that showed the highest variations (i.e., Locustella fluviatilis, Locustella naevia, Alcedo atthis, Bombycilla garrulus, Tetrax tetrax, Tringa totanus, Anthus campestris and Larus ridibundus). It was noted that the general abundance of birds decreased, with farmland birds suffering the biggest decline. Forest bird species population abundance was found to be quite varied; specialist species decreased as compared to generalists, which generally increased.

Long-Term Winter Population Trends of Corvids in Relation to Urbanization and Climate at Northern Latitudes

Article

Full-text available

Jul 2022

Simple Summary Corvids (e.g., crows, magpies and jays) are an important part of urban settlements, especially during winter. To understand the factors affecting the long-term population trends of corvids, we counted wintering corvids in 31 human settlements along a 920 km latitudinal gradient in Finland during four winters between 1991 and 2020. We detected a total of five corvid species, from which the Hooded Crow, the Eurasian Magpie and the Eurasian Jackdaw were found to be common. During the study period, the number of Eurasian Jackdaws increased, and their distribution range moved northwards. No corresponding changes were observed for the Hooded Crow or the Eurasian Magpie. Neither the local-level urban-, climate- nor food-related factors correlated with the changes in the numbers and growth rates of the corvids. No interspecific interactions were observed. We assume that the Eurasian Jackdaw has benefitted from the decreased persecution, and probably also from the large-scale climate warming. Our results suggest that urban settlements are quite stable wintering environments for generalist and omnivorous corvids. Abstract Corvids (crows, magpies, jays) live in a close association with humans, and therefore knowledge about their population status and changes will be an essential part of monitoring the quality of urban environments. Wintering bird populations can track habitat and climate changes more rapidly than breeding populations. We conducted a long-term (1991–2020) winter census of corvid species in 31 human settlements along a 920 km latitudinal gradient in Finland. We observed a total of five corvid species: the Eurasian Magpie (occurring in 114 surveys out of 122; total abundance 990 ind.), the Hooded Crow (in 96 surveys; 666 ind.), the Eurasian Jackdaw (in 51 surveys; 808 ind.), the Eurasian Jay (in 5 surveys; 6 ind.) and the Rook (in 1 survey; 1 ind.). Only the numbers of the Eurasian Jackdaw differed between the study winters, being greater at the end of the study period (2019/2020) than during the earlier winters (1991/1992 and 1999/2000). The average growth rate (λ) of the Eurasian Jackdaw increased during the study period, whereas no changes were observed in the cases of the Hooded Crow or the Eurasian Magpie. The growth rate of the Eurasian Jackdaw was greater than that observed in the Finnish bird-monitoring work, probably because our data came only from the core area of each human settlement. Even though the number of buildings and their cover increased in the study plots, and the winter temperature differed between winters, the average growth rate (λ) of corvid species did not significantly correlate with these variables. These results suggest that urban settlements are stable wintering environments for the generalist corvids. The between-species interactions were all positive, but non-significant. Despite the total number of winter-feeding sites being greater during the winter of 1991/1992 than during the winter of 2019/2020, the changes in the numbers of feeding stations did not correlate with the growth rates of any corvid species. We assume that the Eurasian Jackdaw has benefitted from the decreased persecution, and probably also from large-scale climate warming that our study design was unable to take in to account. Our results indicated that wintering corvid populations succeed well in the human settlements in Finland. We recommend conducting long-term corvid research, also during breeding season, to understand more detailed causes of the population changes of corvids along an urban gradient. Without year-round long-term monitoring data, the conservation and management recommendations related to the corvid species in urban habitats may be misleading.

PARUS program: wintering land bird monitoring in European Russia

Article

Full-text available

Mar 2021

For more than 30 years, the PARUS program has implemented annual censuses of wintering birds across a network of model sites in the European Russia forest zone. The scheme is run mostly by volunteers who make transect counts; it enables the estimation of bird population density in typical forest habitats. We present an analysis of wide-scale population trends in forest habitats using TRIM software for 17 common birds. Between 1988 and 2019, seven species had decreasing trends, populations of nine species were stable, and none showed a significant increase. Species associated with coniferous trees had a more pronounced decline in comparison to generalist species; declines were most dramatic for Goldcrest Regulus regulus, Willow Poecile montanus and Coal Tits Periparus ater. Similar tendencies were reported with monitoring schemes in neighbouring countries. We suppose that main negative factor was intense logging in boreal forests; climate change could also play a role.

Treating gaps and biases in biodiversity data as a missing data problem

Article

Full-text available

Aug 2024
BIOL REV

Big biodiversity data sets have great potential for monitoring and research because of their large taxonomic, geographic and temporal scope. Such data sets have become especially important for assessing temporal changes in species' populations and distributions. Gaps in the available data, especially spatial and temporal gaps, often mean that the data are not representative of the target population. This hinders drawing large‐scale inferences, such as about species' trends, and may lead to misplaced conservation action. Here, we conceptualise gaps in biodiversity monitoring data as a missing data problem, which provides a unifying framework for the challenges and potential solutions across different types of biodiversity data sets. We characterise the typical types of data gaps as different classes of missing data and then use missing data theory to explore the implications for questions about species' trends and factors affecting occurrences/abundances. By using this framework, we show that bias due to data gaps can arise when the factors affecting sampling and/or data availability overlap with those affecting species. But a data set per se is not biased. The outcome depends on the ecological question and statistical approach, which determine choices around which sources of variation are taken into account. We argue that typical approaches to long‐term species trend modelling using monitoring data are especially susceptible to data gaps since such models do not tend to account for the factors driving missingness. To identify general solutions to this problem, we review empirical studies and use simulation studies to compare some of the most frequently employed approaches to deal with data gaps, including subsampling, weighting and imputation. All these methods have the potential to reduce bias but may come at the cost of increased uncertainty of parameter estimates. Weighting techniques are arguably the least used so far in ecology and have the potential to reduce both the bias and variance of parameter estimates. Regardless of the method, the ability to reduce bias critically depends on knowledge of, and the availability of data on, the factors creating data gaps. We use this review to outline the necessary considerations when dealing with data gaps at different stages of the data collection and analysis workflow.

Factors Affecting the Winter Distribution of Birds in Forests at the Eastern Edge of Europe

Article

Full-text available

Jun 2024

We show for the first time the results of a study into the spatial distribution of birds in forests at the eastern edge of Europe (Republic of Tatarstan, Russia) and changes from early to late winter. A transect method was used to census randomly selected plots spread over a large geographical area in the winters 2018/9–2022/3. We used regression and ordination methods to assess the influence of key environmental factors on species richness, total density of birds, biological diversity, and the probabilities of occurrence of individual species. The most abundant bird species in early winter was the Willow Tit, and in the late winter was the Common Redpoll. Compared with the end of the 20th century, the number of wintering bird species has increased in the study area, likely due to climate warming. Species richness, total density, and the Shannon Index of diversity were higher in early winter than in late winter. Species richness and the Shannon Index were also higher at low elevations and in the west of the study region. Our research shows strong ecological-geographical differences in the preferences of individual bird species in the studied forests. However, almost without exception, birds had a higher probability of occurrence at lower elevation and toward the west.

Investigating the heterogeneity within Wild bird indices in Europe

Article

Full-text available

Feb 2024
BIOL CONSERV

Rôle des infrastructures et des pratiques agroécologiques pour la conservation de la biodiversité dans les systèmes de grandes cultures en Camargue

Thesis

Full-text available

Oct 2022

Pierre Mallet

Résumé : L’intensification de l’agriculture est une menace majeure pour la biodiversité. L’homogénéisation des paysages et les changements de pratiques réduisent la quantité et la qualité des habitats disponibles. Dans ce contexte, l’écologie des paysages peut être utilisée dans le but de proposer des modes de gestion agroécologique favorables à la biodiversité. Dans cette thèse j’ai étudié les effets des interactions entre les bordures de parcelles et les pratiques agricoles ainsi qu’entre les bordures de parcelles et les milieux semi-naturels. J’ai pris pour modèle d’étude les paysages rizicoles du delta du Rhône en Camargue. Les paysages camarguais se caractérisent par de grands espaces de zones humides protégés en réserve, des zones de pâturage extensif et de marais à vocation cynégétique et des parcelles de grande culture. Selon leur localisation, ces cultures sont entourées de milieux semi-naturels ou dans des paysages d’openfields. En tant que zone humide majeure du bassin méditerranéen, il existe dans le delta du Rhône des enjeux de conservation de la biodiversité très importants. La Camargue est donc une zone d’étude intéressante pour travailler sur des modes de gestion agroécologique qui permettent de concilier la production alimentaire et la conservation de la biodiversité. En étudiant l’effet de l’hétérogénéité du paysage le long d’un gradient d’intensité d’utilisation de pesticides, je montre que la présence de milieux semi-naturels surfaciques et de bordures de parcelles a un effet positif plus important pour la biodiversité dans les paysages agricoles intensifs. Ces milieux sont utilisés comme des zones refuges par différentes espèces. J’ai ensuite étudié l’effet des surfaces de bordures de parcelles le long d’un gradient de surface de milieux semi-naturels dans des paysages en agriculture biologique. J’ai ainsi mis en évidence le rôle d’habitat de substitution que peuvent avoir les bordures de parcelles pour les oiseaux nicheurs ainsi que leur utilisation comme habitat complémentaire pour les oiseaux hivernants. Cependant, la diversité des niches des espèces rencontrées dans les milieux agricoles camarguais induit des réponses contrastées aux variations de la quantité des différents types d’infrastructures agroécologiques. Afin de prendre en compte ces variations, j’ai modélisé l’effet de la plantation de haies dans le but d’optimiser la conservation de la biodiversité et la fourniture de services écosystémiques. En conclusion, l’intensification agricole est une menace majeure pour la biodiversité, mais l’adoption de pratiques agroécologiques peut permettre de réduire ces impacts et même offrir des milieux favorables aux espèces. La prise en compte des milieux agricoles dans les programmes de conservation de la biodiversité en Europe est donc nécessaire. Abstract: Agricultural intensification is a major threat to biodiversity. The homogenization of landscapes and the changes of practices reduce the quantity and quality of available habitats. In this context, landscape ecology can be used to propose agroecological management methods that are favorable to biodiversity. In this thesis, I studied the effects of interactions between field margins and agricultural practices and between field margins and semi-natural habitats. I used the rice paddy landscapes of the Rhone delta in the Camargue as a study model. The Camargue landscapes are characterized by large protected areas (wetlands mostly), extensive grazing areas and marshes for hunting purposes and crop fields surrounded by semi-natural habitats or, on the contrary, in open fields. Depending on their location, these crops are surrounded by semi-natural habitats or, on the contrary, in open fields. As a major wetland area of the Mediterranean basin, the Rhône delta has very important biodiversity conservation issues. The Camargue is therefore an interesting study area for working on agroecological management methods that reconcile food production and biodiversity conservation. By studying the effect of landscape heterogeneity along a gradient of pesticide use intensity, I show that the presence of semi-natural habitats and field margins has a greater positive effect on biodiversity in intensive agricultural landscapes. These habitats are used as refuges by different species. I then studied the effect of field margins area along a gradient of semi-natural habitat surfaces in organic farming landscapes. I highlighted the role of field margins as substitute habitat for breeding birds and their use as complementary habitat for wintering birds. However, the diversity of niches of species found in the agricultural landscapes of the Camargue induces contrasting responses to variations in the quantity of the different types of agroecological infrastructure. In order to take these variations into account, I modeled the effect of hedgerow planting in order to optimize biodiversity conservation and the provision of ecosystem services. In conclusion, agricultural intensification is a major threat to biodiversity, but the adoption of agroecological practices can reduce these impacts and even provide favorable habitats for species. It is therefore necessary to take into account agricultural landscapes in biodiversity conservation programs in Europe.

Species Traits Drive Long-Term Population Trends of Common Breeding Birds in Northern Italy

Article

Full-text available

Dec 2021

Long-term population trends are considerable sources of information to set wildlife conservation priorities and to evaluate the performance of management actions. In addition, trends observed in functional groups (e.g., trophic guilds) can provide the foundation to test specific hypotheses about the drivers of the observed population dynamics. The aims of this study were to assess population trends of breeding birds in Lombardy (N Italy) from 1992 to 2019 and to explore the relationships between trends and species sharing similar ecological and life history traits. Trends were quantified and tested for significance by weighted linear regression models and using yearly population indices (median and 95% confidence interval) predicted through generalized additive models. Results showed that 45% of the species increased, 24% decreased, and 31% showed non-significant trends. Life history traits analyses revealed a general decrease of migrants, of species with short incubation period and of species with high annual fecundity. Ecological traits analyses showed that plant-eaters and species feeding on invertebrates, farmland birds, and ground-nesters declined, while woodland birds increased. Further studies should focus on investigation of the relationship between long-term trends and species traits at large spatial scales, and on quantifying the effects of specific drivers across multiple functional groups.

Changes in wetland habitat use by waterbirds wintering in Czechia are related to diet and distribution changes

Article

Full-text available

Nov 2021

• Understanding species habitat use and factors affecting changes in their distributions are necessary to promote the conservation of any biological community. We evaluated the changes in wetland use of the non-breeding waterbird community. Based on long-term citizen-science data (1988–2020), we tested the hypotheses that wetland use is associated with species diet and potential range-shift drivers (the tendency to occupy the same sites in consecutive years—site affinity—and the species' average temperature across its wintering range—species temperature index). • We analysed species-specific wetland use of 25 species of waterbirds wintering in Czechia over a period of 33 years. The analyses explained variability in trends in numbers of the studied waterbird species across four inland wetland types: reservoirs; fishponds; industrial waters created by flooding of former mining sites; and running waters. • Trends in waterbird abundance positively correlated with species’ diet on fishponds, industrial and running waters. Among the diet groups, invertivores showed the largest increase in abundances on industrial waters, closely followed by herbivores. Herbivores showed the largest increase in abundances in fishponds, and piscivores did so in running waters. Regarding range-shift drivers, species with higher site affinity showed higher abundances on running waters, while species with low species temperature index (i.e. wintering on average in sites with lower temperature) were more abundant on reservoirs. The abundance of both warm-dwelling and species with low site affinity increased on fishponds and industrial waters. • Our findings suggest that the increased importance of the wetland types considered here for wintering waterbirds is likely to be linked to diet related changes in habitat use and changes in species distributions; and highlight that wintering waterbirds are expected to select sites with higher availability of food, higher energy content, and lower foraging cost. • Recent and rapid changes in species distributions may lead to a decrease in the effectiveness of national and international conservation efforts. When planning conservation measures, it should be kept in mind that climate change does not only imply large-scale north/north-eastwards shifts of entire waterbird distributions, but can also modify the use of the habitats by waterbird species inside their traditional wintering range.

‘Tell me where the birds have gone’ – Reconstructing historical influence of major environmental drivers on bird populations from memories of ornithologists of an older generation

Article

Full-text available

Oct 2021
ECOL INDIC

Historical perspective is important to understand the mechanisms of current environmental impacts on biodiversity. It may be achieved through long-term monitoring schemes aiming to record biodiversity changes over time. However, even the monitoring of bird populations, a taxon with the broadest spatial coverage and the longest time series among all organisms, does not usually cover more than 30–50 years. It is thus possible that the population status recorded by the monitoring schemes resulted from impacts preceding the monitoring data. In European birds for example, most studies use the beginning of 1980s as a baseline, even though major environmental changes likely acted earlier and its possible that many species have already depleted populations at that time. To fill this knowledge gap, we performed a unique survey among ornithologists of an older generation who performed bird observations in the Czech Republic from 1950s or 1960s up to now. They were asked to fill in a questionnaire to record relative abundance of each species in the region of their expertise during three time periods: 1950s/1960s, 1980s, and 2010s. Comparison of relative abundance between 1950s/1960s and 1980s should reflected population change prior to the time period typically set a as baseline, whereas population change between 1980s and 2010s aimed to assess the reliability of the ornithologists’ assessment by comparison with objective atlas mapping data. As expected, ornithologists of an older generation reported major population declines between 1950s/1960s and 1980s, especially among species depending on insects in their diet corresponding with steep intensification of land use for agriculture. Species associated with wetlands increased their populations, likely due to a higher nutrient input into water bodies. Interestingly, bird populations showed opposite pattern to the currently observed climate change impact, probably due to the modest climate change over these time periods. Importantly, population change between 1980s and 2010s estimated by the ornithologists corresponded well with the change based on atlas mapping data between the same time periods. Such a high level of congruence indicates suitability of memories of older generation naturalists for inferring indicators of historical biodiversity changes. We urge for performing of such assessments in other regions and for other taxa before this source of information will be lost forever.

Winter Bird Richness Distribution in the South-Western Palearctic: Current Patterns and Potential Changes

Article

Jul 2020

This paper explores how environmental traits shape the winter distribution of passerine (O. Passeriformes) richness in the south-western Palearctic, a major wintering ground for the European avifauna. We apply three complementary approaches. First, we assess the way climate, landscape and habitat affect species richness by means of field counts across the study area. Second, we model the spatial distribution of six common passerines using ring recoveries as presence data. Finally, where the resulting models predict the actual distribution of birds, we employ the models to forecast the future distribution of richness according to predictions of climate change, i.e. of increasing temperature and decreasing precipitation. The results support an effect of landscape, habitat structure, temperature and precipitation on bird richness. Distribution models fit the actual distribution of bird richness and their predictions suggest that winter species richness will decrease in lowlands and increase in highlands. This pattern could be related to direct effects of temperature on thermoregulatory costs and indirect effects on winter primary productivity affecting food resources. These results also indicate that, in a context of climate warming, species-rich sectors will shift from lowlands to highlands, suggesting that uplands will have a regulatory role in the future winter distribution of birds.—Tellería, J.L., Fandos, G. & Fernández-López, J. (2021). Winter bird richness distribution in the south-western Palearctic: current patterns and potential changes. Ardeola, 68: 17-32.

Long-term effects of combined land-use and climate changes on local bird communities in mosaic agricultural landscapes

Article

Nov 2019
AGR ECOSYST ENVIRON

Rural landscapes of western Europe have considerably changed in the last decades under the combined pressure of climate and land use changes, leading to a dramatic decline of farmland biodiversity, including common farmland birds. The respective roles of climate and land use and cover changes in driving bird population trends are primarily assessed at national or continental levels. Yet, it is often challenging to integrate their intertwined effects at such large scales due to the lack of data on fine-scale land cover changes. Here, we used a long-term bird monitoring scheme, combined with a land cover survey, conducted during 30 years (1981-2011) across 780 sites in a 20,000 ha study area in southwestern France, dominated by low-intensity farming systems. We tested the direct effect of temporal changes in climate and land use on the dynamics of two community-level metrics: the bird Community Thermal Index (CTI) and bird Community Generalization Index (CGI). We used a novel method to assess the contribution of species-specific dynamics to CTI and CGI trends. We observed a significant increase in CTI and a significant decrease in CGI between 1981 and 2011, i.e., bird communities now have higher thermal preferences and are more specialized than 30 years ago. Bird CTI and CGI changes were both related to local climate-and land use-related drivers, especially mean temperature increase and hedgerow loss. Trends in CTI and CGI were primarily driven by the loss of cold-dwelling and generalist species, and secondly by a gain in hot-dwelling specialists. Our long-term study brings new empirical evidence that the effects of climate and land cover changes on bird communities are intrinsically intertwined, and need to be considered together to monitor and predict the future of farmland biodiversity. It also suggests that low-input, diversified agriculture combined with the maintenance of semi-natural habitat cover can contribute to the conservation of both specialist and generalist bird communities in agricultural landscapes experiencing rapid climate change.

Temporally Stable Species Occupancy Frequency Distribution and Abundance–Occupancy Relationship Patterns in Urban Wintering Bird Assemblages

Article

Full-text available

Apr 2019

Urbanization is negatively affecting biodiversity worldwide, and general ecological patterns may also differ between urban and more natural areas. The main aim of this study was to examine if urbanization has effects on the wintering species occupancy frequency distribution (SOFD) and species abundance–occupancy relationship (SAOR), and if the observed patterns varied between winters, different sizes of towns, and regionally in Finland. In this study, temporal variation of the SOFD and SAOR patterns was studied in 29 town and village centers along a 950-km (60–68°N) latitudinal gradient during mid-winters in Finland. Wintering birds were counted during three winters (1991–1992, 1999–2000, and 2009–2010) from the same study sites and with the same survey methods. A total of 35 wintering bird species and 13,285 individuals were detected. The bimodal symmetric SOFD pattern explained best the distribution of species in the pooled data, and the observed pattern was constant between the study winters, different sizes of towns, and towns located in southern and northern Finland. Three species (Parus major, Pica pica, and Passer domesticus) were core species during all winters, irrespective of the size of town or latitude. There was a slightly higher number of species belonging in satellite species group in the southern than in the northern towns. No changes of species from the core to satellite species were detected, and vice versa. However, the occupancy rate of some species belonging to the intermediate species group either moved toward satellite species or core species across winters. The SAOR pattern was positive and stable over study winters and did not differ between different sizes of towns or town location. Our results indicated that urbanization leads a structure of winter bird community, where there are few widely distributed sedentary core species and many partially migratory or migratory satellite species with a restricted distribution. Our results also demonstrated that urbanization stabilizes between-winter community structure, probably because of intensive winter feeding activities. Our results give support to the metapopulation model, which predicts a bimodal SOFD pattern.

Devine qui vient dîner … : graines des villes et graines des champs, ou l'impact de l'agriculture péri-urbaine sur les oiseaux des jardins

Thesis

Jan 2018

Pauline Pierret

Nourrir les oiseaux dans les jardins privés est une activité très répandue en Occident. Elle fournit une remarquable opportunité de recherche et de suivi des populations d’oiseaux en hiver sur de larges échelles spatio-temporelles, en impliquant les citoyens dans des programmes de science participative. Nous avons utilisé le programme Oiseaux des Jardins, un programme de science participative coordonné par la Ligue de Protection des Oiseaux, pour étudier sur une grande échelle spatiale les variations d’abondance d’oiseaux en hiver dans les jardins qui fournissent de la nourriture. Le but de cette thèse est de comprendre quels paramètres peuvent expliquer les visites des oiseaux dans les jardins en hiver, saison traditionnellement considérée comme la plus décisive pour leur survie. Nous montrons que les jardins distribuant de la nourriture, proches de milieux agricoles intensifs, attirent les oiseaux en réponse à une raréfaction des ressources alimentaires naturelles, causée par l’intensité des pratiques agricoles. Cette relation est encore plus forte pour les espèces spécialistes des milieux agricoles. Les variations d’abondance d’oiseaux dans les jardins fluctuent selon les années et les conditions météorologiques, sans présenter de pattern de réponse commun entre espèces, en raison de leur biologie et écologie différentes. Ce suivi des oiseaux en hiver reflète également la tendance négative de population de plusieurs granivores, connue en France ou en Europe en période de reproduction, confirmant que l’utilisation des jardins avec mangeoires est un bon moyen de suivre les tendances des populations d’oiseaux. Nous suspectons que les variations d’abondances à l’échelle spatiale peuvent également refléter l’effet d’activités humaines, telles que le braconnage des passereaux, mais un travail supplémentaire est nécessaire pour confirmer cette hypothèse. Les résultats de cette thèse peuvent également aider au maintien des espèces granivores en déclin, en apportant des conseils adaptés à la distribution de nourriture de substitution pour les oiseaux dans les paysages agricoles intensifs, tout en continuant à engager le public dans le suivi et la protection de la nature.

How can we improve citizen science based bird monitoring in Denmark?

Article

Full-text available

Oct 2018

Citizen science is an indispensable means of obtaining the information necessary for maintaining bird monitoring programmes. The aim of this paper is to inspire creative thought and discussion among the ornithological community, scientists and decision makers in Denmark to improve the quality and extent of breeding bird monitoring. We review the status of monitoring programmes in Denmark and use this information as a basis for discussing how we could best improve citizen science based bird monitoring programmes in the future. We undertake a gap analysis to establish some immediate priority areas for attention. In particular, we argue for initiating programmes that deliver information on demography parameters such as survival, reproduction, immigration and emigration to better interpret overall trends in abundance. We suggest combining data from different monitoring programmes to develop the possibilities for the integrated analyses of population counts and demographic data within population models, which will contribute to more effective management and conservation in the future. Dansk Orn. Foren. Tidsskr. 112 (2018): 90-104

Time, geography and weather provide insights into the ecological strategy of a migrant species

Article

Aug 2018
SCI TOTAL ENVIRON

Farmland and migratory bird populations are in decline. The Common quail (Coturnix coturnix) provides an exception to this trend and its populations have remained stable over the last two decades. However, some basic facts regarding quail biology and ecology, such as the geographic distribution of age and sex classes during the summer, remain poorly understood. We analyzed 43,194 Spanish quail ringing records from1961 to 2014 to assess the effects of geography andweather conditions on the probability that individualswill be ringed during the various stages of their annual cycle (arrival –spring migration-, stationary breeding period, departure –autumn migration- and winter) for the different quail age-sex classes over time. We found that spatial distribution of the age and sex classes can be explained by date, latitude, longitude, altitude, rainfall, and temperature. Our results suggest that date accounts for most of the variation in the distribution of quail age classes, followed by the weather variables, and then latitude, and altitude. Similarly, date also accounts for most of the variation in the distribution of the two sexes. These results could partially explain why this species has avoided population decline, since its ecological strategy is based on its temporal and spatial distribution combined with the segregation of age and sex groups. We hypothesize that the distribution of quail age and sex classes follows variations in weather and habitat suitability to exploit seasonal and geographic variations in resource availability. The migratory and nomadicmovements of quail, combinedwith the occurrence ofmultiple breeding attempts within a single season, may also allow these birds to overcome the impacts of predators and anthropogenic environmental

Small populations of fig trees offer a keystone food resource and conservation benefits for declining insectivorous birds

Article

Full-text available

Jun 2018

Novel restoration approaches are required to provide food and habitat for declining bird populations, particularly as pressures increase from growing human populations and climate change. Fig (Ficus) species support many frugivores but there is a gap in our knowledge about the importance of these insect-pollinated plants to insectivores. We tested the influences of fig-population size and the number of fig-wasp-producing fruit per tree on avian-insectivore visitation to fig trees in eastern Australia over a three-year period. Eighty-four bird species visited fig trees in our study; two thirds (55) of these species were insectivores. More individual insectivores (1686) than frugivores (1051) visited fig trees (p < 0.0001). More insectivore species visited individual fig trees in small, fragmented populations (<16 fig trees) than in large populations (>50 fig trees; p = 0.016). We showed that figs provide insectivores with an important, year-round, food source. We showed that this occurred in a dry, temperate ecosystem and in a mesic, sub-tropical ecosystem. Insectivore visitation was significantly correlated with the number of ripening fig syconia and the number of emerging fig wasps but not with abundances of other insects in fig trees. Temporal resource partitioning between insectivores and frugivores was identified, with insectivores foraging as fig syconia were ripening, and frugivores foraging after syconia had fully ripened. Ficus species are very likely to provide similar keystone resources for avian insectivores throughout tropical, subtropical and temperate regions globally. This study revises our understanding of the role played by Ficus trees in supporting avian-insectivore populations.

Disentangling the effects of multiple environmental drivers on population changes within communities

Article

Mar 2018

The effects of different environmental drivers on the changes in species’ population abundances can be difficult to disentangle as they often act simultaneously. Researchers have built statistical models that include environmental variables (such as annual temperature) or species attributes (such as a species’ temperature preference), which are assumed to detect the impacts of specific drivers (such as climate change). However, these approaches are often applied separately or, if combined, not explicitly compared. We show the complementary insights gained by applying both these approaches to a community dataset on Danish terrestrial birds. We use our analysis to compare the relative importance of climate change and agricultural land‐use change for the abundance changes within the community between 1983 and 2013. Population models were fitted to the community data of species’ annual abundances with predictors comprising: species attributes (species’ temperature and habitat preferences), environmental variables (climatic and agricultural land‐use change variables) or both. Relationships between species’ abundances and environmental variables were used to identify the drivers associated with average abundance changes of species in the community. Relationships between species’ abundances and their attributes were used to understand the drivers causing interspecific variation in abundance changes. Warmer winters were positively associated with community‐level abundances, and warm‐adapted species had more positive abundance changes than cold‐adapted ones. Agricultural land‐use area was negatively associated with community‐level abundances, and birds using a high proportion of meadow and habitat specialists had more negative abundance changes than birds using other habitats and habitat generalists. Effect sizes of environmental variables were larger for agricultural land‐use change while those of species attributes were larger for climate change. The environmental data approach suggested that agricultural land‐use change has decreased the average abundances of species in the community, affecting total community size while the species attribute‐based approach suggested that climate change has caused variation in abundance among species, affecting community composition. Environmental variables and species attributes that are hypothesized to link to specific drivers can be used together to provide complementary information on the impacts of different drivers on communities.

New records and probable migration routes of the Sora Porzana Carolina (Aves: Rallidae) in Peru

Article

Full-text available

Sep 2017

The Sora Porzana carolina is the most abundant rail of North America, and historical records (1877–1994) indicate Peru as the southern limit of its wintering (October–May) range. Here, we present data from three consecutive austral summers (February/2014 to March/2016) recording this species on wetlands in north Peru, which fill a geographic gap of approximately 1000 km between Tumbes and Lima regions. Based on our records and secondary sources for South America, we indicate that Sora probably follows two parallel migration routes in western South America: the Pacific Coast and the Andean routes. Another recent study recorded Sora in Cusco province, which suggests that Peruvian Andes wetlands may currently becoming more important as non-breeding sites for Nearctic migrant waterbirds. Unlike the sites of historical records of Sora in Peru, the wetlands on which this rail was recently recorded have no legal protection, deserving management policies and continued monitoring

Sustainable harvesting of wild seaweed resources

Article

Full-text available

Oct 2017

Macroalgae have played an important role in coastal communities for centuries. In the past, they have been harvested and gathered from shorelines around the world for traditional uses such as food, animal feed and a crude fertilizer (marine manure). Today, seaweeds are used in a multitude of applications with expanding global industries based on hydrocolloids, cosmetics and food supplements, and also as a potential biofuel source. However, of the approximately 10 000 algal species reported to exist, only a small number are commercially utilized. While representing only a small fraction of total global seaweed production, harvesting and gathering ‘wild’ seaweeds has had, and continues to have, an integral role in many coastal societies, often being intrinsically linked to the cultural identity of those coastal communities. Today, 32 countries actively harvest seaweeds from wild stocks, with over 800 000 t harvested annually from natural beds. It is vitally important that seaweeds are utilized sustainably and that natural resources are effectively managed by coastal communities with vested interests around the world. As the popularity of seaweeds increases and the use of less traditional species with novel applications comes to the fore, it is critically important to make certain that the sustainability of the resource is ensured given the increased pressures of harvesting. Issues exist regarding ownership of the resource and its over-exploitation, and the implementation of environmentally damaging harvesting techniques must be avoided. Resource scientists, managers, conservationists, governments, and other stakeholders need to be proactive in the sustainable management of these vulnerable, yet valuable, resources.

Bird populations in a changing world: implications for North European conservation

Thesis

Full-text available

May 2017

Sara Fraixedas

The combined effects of climate and land-use change constitute a major threat to global biodiversity. Accurate tools to track changes in biodiversity have been largely called upon in order to address global conservation targets. In response to this, a range of ecological indicators have been developed to measure the state of biodiversity in a changing world. Because of their sensitivity to environmental changes, birds are increasingly used in the construction of multi-species indicators, which represent a powerful tool for decision-makers to assess conservation effectiveness. This work aims to further our understanding of the general state of bird populations in Finland and the underlying ecological processes behind corresponding trends, covering different environments and with a special focus on some of the most threatened ecosystems of northern Europe. Using data on common bird species, the effects of climate change and anthropogenic habitat degradation on bird populations are quantified for different habitat types and seasons of the year. Habitat-specific indicators are also produced to deepen knowledge about large-scale impacts taking place in the environment while allowing an evaluation of the conservation status of bird populations, thus helping target the most critical conservation issues. Although the effects of climate and land-use change on bird populations vary significantly with the habitat type and the life-history traits of the species (e.g. migration strategy), the conservation status of nearly all studied communities is considerably deteriorating in both Finland and its neighbouring Northern European countries. Peatlands and forests are of particular concern, given that intensive management actions are severely impacting the inhabiting bird communities.

Assessing vulnerability of giant pandas to climate change in the Qinling Mountains of China

Article

Full-text available

Apr 2017

Climate change might pose an additional threat to the already vulnerable giant panda (Ailuropoda melanoleuca). Effective conservation efforts require projections of vulnerability of the giant panda in facing climate change and proactive strategies to reduce emerging climate-related threats. We used the maximum entropy model to assess the vulnerability of giant panda to climate change in the Qinling Mountains of China. The results of modeling included the following findings: (1) the area of suitable habitat for giant pandas was projected to decrease by 281 km2 from climate change by the 2050s; (2) the mean elevation of suitable habitat of giant panda was predicted to shift 30 m higher due to climate change over this period; (3) the network of nature reserves protect 61.73% of current suitable habitat for the species, and 59.23% of future suitable habitat; (4) current suitable habitat mainly located in Chenggu, Taibai, and Yangxian counties (with a total area of 987 km2) was predicted to be vulnerable. Assessing the vulnerability of giant panda provided adaptive strategies for conservation programs and national park construction. We proposed adaptation strategies to ameliorate the predicted impacts of climate change on giant panda, including establishing and adjusting reserves, establishing habitat corridors, improving adaptive capacity to climate change, and strengthening monitoring of giant panda.

Long-Term Monitoring of Fish Abundance Dynamics in the Middle Stretch of the Mesha River (Tatarstan)

Article

Full-text available

Aug 2024

The study area is located in the middle reaches of the Mesha River on the territory of the Republic of Tatarstan and is characterized by strong temporal variability in environmental factors and fish populations. The impact of environmental factors on fish species and communities was analyzed with regression and ordination methods. The dominant species were bleak, dace, chub, and roach, which together accounted for 60.7% of the total fish species. Over 15 years of research, there have been significant decreasing trends in overall density, species richness and density of individual fish species. The main factors determining the size of both the fish population and individual species were fishing effort and temperature during different months. The index of long-term similarity of fish populations was only 7.5%.

How, why, where and when people feed birds?—Spatio‐temporal changes in bird‐feeding in Finland

Article

Full-text available

Nov 2024

Providing food to animals, especially birds, during winter is a common activity in many countries. While bird‐feeding can increase connections between people and nature, there are increasing calls from researchers and the general public to limit this activity due to emerging knowledge of potential negative ecological impacts (e.g. biased competition and spread of pathogens). However, what motivates changes in bird‐feeding habits remains largely unknown, despite the ‘provisioners’ perspective’ being critical for designing and implementing policy that benefits both animals and people. Here, we investigate changes in how and why people feed birds in urban and rural areas of Finland as a case study. We made use of two long‐term annual bird monitoring data sets (the Winter bird census and Finnish bird feeder monitoring scheme) to investigate how the number of bird‐feeding sites and the amount of food provisioned have changed since the 1980s. Additionally, we conducted an online questionnaire in 2021 (over 14,000 respondents) to examine reasons for the changes that we detected. We find that, over 40 years, the annual amount of food provided has increased significantly in rural areas, while the number of bird‐feeding sites has decreased and especially so in urban areas. Questionnaire answers indicated that this decline was likely due to changing regulations of local governments and housing organisations, with increased concerns of attracting pests leading to restrictions on providing food for birds. In rural areas, people who reduced feeding more often identified concerns over avian diseases and the effort required to access, clean and refill bird‐feeding sites. Policy implications: Our results highlight that provisioning food to wild animals involves complex decision‐making depending on habitat, geography and economic factors. Therefore, policies designed to curb (or promote) this activity should take into account its multifaceted nature. Read the free Plain Language Summary for this article on the Journal blog.

Historical park planning is associated with modern-day patterns of bird diversity in cities

Article

Jun 2024
Landsc Plann

THE ROLE OF CLIMATE CHANGE AND FOOD SUPPLY ON WINTER POPULATIONS OF SEED-EATING BIRDS

Article

Full-text available

Jan 2023

We studied the populations of four seed-eating bird species throughout the winter during a 30-year study in the forests of the Tatarstan Republic, Russia. Numbers of all species fluctuated from year-to-year by several orders of magnitude but with a significant underlying trend for increased numbers associated with rising temperatures and a greater food supply. We question whether the traditional view that such birds move further south only after exhausting the food supply is too simplistic. We believe that the severity of winter, or lack of it, is highly influential on the mortality and movements of these characteristic birds of the boreal forest zone.

Panel-based Assessment of Ecosystem Condition – a methodological pilot for four terrestrial ecosystems in Trøndelag.

Technical Report

Full-text available

Mar 2022

The panel-based assessment of ecosystem condition (PAEC) is an evidence-based ap-proach to assess the condition of Norwegian ecosystems. The assessment is carried out by an expert panel with broad expertise in the ecosystems to be assessed and is inspired by approaches used in international assessments such as IPCC and IPBES. The assessment follows an earlier developed protocol. In this report, PAEC is piloted for major terrestrial ecosystems in the county of Trøndelag; forest, alpine, open-lowlands, and wetlands. For each ecosystem, a list of indicators of change in ecosystem condition in response to anthropogenic drivers is developed. The indicators fall within seven main ecosystem char-acteristics: primary production, biomass distribution among trophic levels, functional groups within trophic levels, functionally important species, biological diversity, landscape ecologi-cal patterns, and abiotic factors. The expected change in indicators in response to anthro-pogenic drivers are termed phenomena, and their selection is based on published literature, including reference to the confidence of a change being observed in response to anthropo-genic drivers and the mechanism leading to a deterioration in ecosystem state. Datasets to quantify each indicator are identified and collated and the quality of each dataset is assessed in terms of its spatial and temporal appropriateness. In the first assessment step, the validity (VP) of each phenomenon is scored and used to infer confidence in the causal relationship between changes in the indicator and anthropo-genic drivers. The next step is an evaluation of the biological and statistical significance of the evidence for the occurrence of each phenomenon, termed evidence (EP) of the phe-nomenon. The third step is a consolidated assessment of the ecological state based on the associated indicators and phenomena, first for each ecosystem characteristic, and subse-quently for the ecosystem as a whole. The assessment is based on the validity, the quality of the evidence, and the data quality for each phenomenon. This provides a qualitative as-sessment of deviation from the reference condition of “no deviation”, “limited deviation” or “substantial deviation”. The assessments are each supported by narrative accounts. The pilot assessment involved analysis of 24 datasets documenting 41 indicators. Several indi-cators were included in multiple ecosystems. In total there were 27 indicators used for forest ecosystems, 24 for alpine ecosystems, and 16 in each of wetlands and open lowlands. In the forest ecosystems, substantial deviation from the reference condition was identified for five of the ecosystem characteristics. The two exceptions were primary productivity where there was a limited deviation from the reference condition, and biological diversity where there was no deviation from the reference condition (but the latter was based on a single indicator and hence an entirely inadequate indicator coverage). The deviations were found primarily in climatic variables, cervids and their forage and predators, and dead wood. Overall, the forest ecosystem was assessed as having a substantial deviation from the ref-erence condition. In the alpine ecosystems, substantial deviation from the reference condition was identified for the abiotic ecosystem characteristic, largely attributed to indicators associated with tem-perature, seasonality, and snow. Limited deviation from the reference condition was as-sessed for functionally important species and primary productivity (both based on a partially NINA Report 2094 4 adequate indicator coverage) and for biological diversity, functional groups within trophic levels and landscape ecological patterns (but these were based on an inadequate indicator coverage). For the ecosystem characteristic biomass distribution among trophic levels, the quality of evidence was insufficient to conclude regarding the condition of the single indicator involved, and no overall assessment of this ecosystem characteristic could be undertaken. Overall, the alpine ecosystem was assessed as having limited deviation from the reference condition. For both open lowland and wetland ecosystems, several ecosystem characteristics were not assessed due to a lack of relevant indicator datasets. For this reason, no overall assess-ment of the ecosystems as a whole could be undertaken. However, for both ecosystems, there was a substantial deviation from the reference condition for abiotic factors (tempera-ture, seasonality, and snow). In open lowlands, there was a substantial deviation in func-tionally important species (ungulates) and limited deviation in primary productivity and bio-logical diversity. In wetlands, there was a limited deviation from the reference condition in primary productivity, biological diversity, and landscape ecological patterns. Most challenges encountered during this pilot assessment related to the inadequacy of the datasets for assessing ecosystem condition. Reasons behind this include that ecosystem ex-tents are not adequately mapped, particularly those characterised by small and fragmented patches, and a taxonomic or geographical limitation of datasets and environmental monitoring. The report suggests further development of indicators for operational application. Finally, the report also suggests knowledge needs and prioritisation for further research to support the future implementation of ecosystem assessments in Norway.

Impacts of climate change on the forest ecosystem

Technical Report

Full-text available

Apr 2022

In this report, we summarize the current state of knowledge and best estimates of how climate change is expected to impact Norwegian forest ecosystems from now to the year 2100

Snow depth drives habitat selection by overwintering birds in built‐up areas, farmlands and forests

Article

Full-text available

Feb 2022

Aim: Abundances of animals vary according to species-specific habitat selection, but habitats are undergoing rapid change in response to anthropogenic alterations of land use and climate. The long-term decline of snowfall is one of the most dramatic abiotic changes in boreal regions, with potential to alter species communities and shape future ecosystems. However, the effects of snow cover on habitat-specific abundances remain unclear for many taxa. Here we explore whether long-term declines in snow cover affect the abundances of overwintering birds. Taxon: Fifty bird species. Location: Finland, Northern Europe. Methods: We used generalized linear mixed models to analyse citizen-led monitoring data from 196 transects over a 32-year period to assess whether abundances of birds have changed in built-up areas, farmlands and forests, and whether these covary with warming temperatures and decreasing snow. We then explored if changes in abundance can be explained by body mass, migration strategy or feeding guilds of the species. Results: Over the study period, the abundance of overwintering birds increased. This increase was most pronounced in farmlands (69.6%), where abundances were positively associated with decreasing snow depth. On the other hand, while abundances in built-up habitats (19.5%) decreased over the study period, they increased in periods of high snow depths. Finally, we found that the short-distance migration strategy explains changes in bird abundances with snow. In farmlands, ground feeding birds and heavier birds also show a positive trends in abundance with decreasing snow depths. Main conclusions: Local snow conditions are driving habitat selection of birds in the winter; birds in farmlands were most responsive to a decrease in snow depth. Changing snow depths can affect bird movements across habitats in the winter, but also influence migratory patterns and range shifts of species.

Woodpecker populations in winter in the interior of the European continent are highly dependent on climate change and its consequences

Article

Full-text available

Jan 2022

The climate of Eastern Europe has undergone major changes in recent decades. Significant increases in seasonal temperatures and in droughts in the Republic of Tatarstan have adversely affected the status of the forests. As a consequence, the number of woodpeckers in these forests has been affected. The aim of this study was to investigate the impact of climate change and its consequences on winter population dynamics of seven species of woodpeckers. Woodpeckers were censused over a 30 year period using transect methods on fixed plots spread over a large geographic area. The abundance of four species in the first half of the winter, and five species in the second half of the winter, showed significant increases. Ordination and regression analysis showed that the main factors determining the number of woodpeckers in winter were: mean minimum winter temperature, winter severity, date of the start of permanent snow cover, number of withering and dying trees in forests, and, for Great Spotted Woodpecker, the abundance of seeds of pine and spruce. We show that the abundance of woodpeckers in the first half of winter influences the numbers in the second half. However, abundance in late winter is determined to a greater degree by winter severity and the presence of food substrates. We found that increased average minimum winter temperature, a late start to winter, and a good food supply can increase densities of most woodpecker species in the late winter period. This is consistent with trends of greater survival in woodpeckers by the start of the breeding period. The resulting “mixed” picture of the impact of environmental parameters on the number of birds arises from the mutual influence of these impacts. Only such an influence could, in our opinion, cause the observed long-term changes in woodpecker species densities.

The status of winter land bird monitoring in Europe

Article

Full-text available

Nov 2016

Danmarks fugle gennem to århundreder (Summary: Trends in the Danish bird fauna since 1800) Dansk Orn. Foren. Tidsskr. 115 (2021) 1-184

Article

Full-text available

Mar 2021

Danish landscapes have seen greater changes in the last 200 years than most people probably imagine. In the early 19th century, forest cover had been reduced to a few percent of the land area, and the other landscapes were dominated by heaths, commons, meadows and depleted fields. Nowadays, not only is there about five times as much forest, but there are also probably several thousand times as many trees and shrubs scattered throughout the landscape. This situation has multiplied the numbers of many bird species dependent on trees and shrubs. Conversely, much of the open country has become massively impoverished, with drainage of wetlands, cultivation of commons, heaths, and meadows as well as intensified farming having led to marked declines in the populations of many open country birds. Hunting has been one of the most negative factors for many breeding birds as well as for staging and winter visitors. During the 20th century, however, many populations recovered following better conservation regulations. Even though millions of breeding birds have disappeared from agricultural land since the middle of the 20th century, we probably have more birds in Denmark today than 200 years ago as a result of many areas becoming overgrown with trees and shrubs. This monograph describes the effects on the Danish bird fauna of all these changes in landscapes, climate, environment, and societal attitudes.

Increasing numbers of wintering forest birds in Swedish Lapland 1986–2017 show stronger correlations with forest development than with local weather

Article

Full-text available

Feb 2020

After a long period of decline, the number of forest birds has increased in Sweden in recent decades. Whether this trend is due to an increase in forested area, forest quality, climate change, or a combination of these factors, remains unclear. Here, we compared forest bird data from a local winter point count route around Storuman in Swedish Lapland between 1986 and 2017, with the development of regional forest composition and local weather conditions. We suggest that rather than changes in average annual, winter, or summer local temperatures or precipitation, the main drivers behind increasing numbers of wintering forest birds in this part of Sweden are an increase in the area of denser forest and dead wood volume, and a decrease in open ground area without forest vegetation. While there may be supplementary explanations behind the increasing numbers of forest birds, such as reduced agriculture, decreasing local human population, or stronger photosynthesis, our results indicate that local land use has been favourable for forest birds in recent decades in this area.

Rapid climate change has increased post-breeding and autumn bird density at the eastern limit of Europe

Article

Full-text available

Jan 2020

We investigated how the densities of birds in the post-breeding and autumn phase (hereafter called autumn) were changing and how they were influenced by a changing climate in a study region that experienced about 5 months of snow cover each winter and summer temperatures that varied greatly from year to year. Bird densities during autumn were estimated between 1991 and 2018 using distance sampling along transects. Densities were compared to various temperature variables in preceding months and to densities in the following winter. The study region has experienced rapid temperature change in May-August, and autumn densities of six of the nine studied species increased significantly during the study period. Autumn densities of all but one bird species were significantly related to one or more of the temperatures in the preceding January-February, affecting adult survival, and in the preceding May-August, affecting nestling survival. Long-term trends of autumn densities and densities in the first half of winter were similar for practically all bird species. The results of our study of seasonal dynamics based on eight-month intervals in each of the 28 years of research emphasize that understanding the influence of climatic parameters on changes in the density of individual bird species requires such long-term monitoring throughout the year. In a period of climate warming, and in spite of the severity of the winter and the variability of summer , we found that most species of birds showed a clear increase in density. K E Y W O R D S autumn bird monitoring, climate change, densities, long-term dynamics, Tatarstan Republic

New measures for evaluation of environmental perturbations using Before‐After‐Control‐Impact analyses

Article

Full-text available

Jan 2019
ECOL APPL

Before‐After‐Control‐Impact (BACI) designs are powerful tools to derive inferences about environmental perturbations (e.g., hurricanes, restoration programs) when controlled experimental designs are unfeasible. Applications of BACI designs mostly rely on testing for a significant interaction between periods and treatments (so‐called BACI contrast) to demonstrate the effects of the perturbation. However, significant interactions can emerge for several reasons, including when changes are larger in control sites, such that additional diagnostics must be performed to determine the full complexity of system changes. We propose two measures that detail the nature of change implied by BACI contrasts, along with its uncertainty. CI‐divergence (Control‐Impact divergence) quantifies to what extent control and impact sites have diverged between the after and the before period, whereas CI‐contribution (Control‐Impact contribution) quantifies to what extent the change between periods is stronger in impact sites relative to control sites. To illustrate how these two CI measures can be combined with BACI contrast to gain insights about effects of environmental perturbations, we used count data from the Swedish Breeding Bird Survey to investigate how hurricane Gudrun affected the long‐term abundances of four bird species in forested areas of southern Sweden. Before‐After‐Control‐Impact contrasts suggested the hurricane affected all four species. However, the values of the two CI measures strongly differed, even among species showing similar BACI contrasts. Those differences highlight qualitatively distinct population trajectories between periods and treatments requiring different ecological explanations. Overall, we show that BACI contrasts do not provide the full story in assessing the effects of environmental perturbations. The two CI measures can be used to assist ecological interpretations, or to specify detailed hypotheses about effects of restoration actions to allow stronger confirmatory inference about their outcomes. By providing a framework to develop more detailed explanations and hypotheses about ecological changes, the two CI measures can improve conclusions and strengthen evidence of effects of conservation actions and impact assessments under BACI designs.

Hoe onze flora en fauna veranderen door klimaatverandering [How climate change affects flora and fauna in the Netherlands]

Article

Full-text available

Nov 2018

In the Netherlands climate change has a profound effect on the distribution of numerous plant and animal species. However, whether and how different taxonomic groups are able to track climate change is still largely unclear. Following a method developed by Devictor et al (2012) we measure changes in the Community Temperature Index (CTI) over time for breeding birds, butterflies, moths, dragonflies and plants in the Netherlands. All groups show a significant change in CTI, which means that communities are changing in a way that thermophile species got relatively more abundant than thermophobe species. The rise in CTI is approximately ten times slower than the real rise in temperature. This means that although communities are changing, they react slower and have the risk to 'lag behind'.

Birds in boreal protected areas shift northwards in the warming climate but show different rates of population decline

Article

Oct 2018
BIOL CONSERV

Climate change has the potential to have wholesale impacts on species populations, driving them polewards and upwards, and even affecting populations occurring within protected area (PA) networks. We studied population changes in bird species in the boreal PA network of Finland based on extensive bird census data collected in the years 1981-1999 and in 2000-2017. Between these time periods, the mean annual temperature increased in Finland by 1.1 °C, and the mean weighted density of the species shifted 28.5 km (1.8 km/year) northwards in the PA network. However, the total bird population density simultaneously declined by approximately 10%. The decline was most pronounced in long-distance migrants, which showed strongest population contraction in southern boreal regions. In contrast, resident species increased between the two time slices, particularly in larger PAs. While the PA network of boreal native habitats appears to be successful in preserving resident species, climate-induced changes have also caused a decline in the populations of migrants in the PAs. Thus, life-history characteristics of species can significantly affect the success of conservation efforts in a warming climate. To enhance future survival of resident and migrant bird species moving to Finland and northwards, the PAs should be larger and the connectivity of the PA network improved in southern and central Finland. In addition, international actions are needed to enhance the survival of long-distance migrants during the migratory period and in overwintering grounds.

Long-term bird population changes in the protected areas of Finland under climate change

Conference Paper

May 2018

Recent climate change has increased forest winter bird densities in East Europe

Article

Full-text available

Feb 2018

Recent studies on climate change have reported serious impacts on winter forest birds in Western Europe. However, in areas where climate change has caused milder winters and more stable conditions in summer, one would expect resident bird populations to increase, rather than to decrease in winter. The aim of this study was to investigate the impact of climate change on the population dynamics of ten species of Passeriformes in the Tartarstan Republic, Russia. Ravkin’s transect method was used to census fixed randomly selected plots spread over a large geographic area at least once every month for the past 26 years. Observers remained the same over the whole period. The abundance of nine species in the first half of the winter and four species in the second half of the winter showed significant increases during the study period. Unlike studies from countries in Western Europe, there were no significant decreases in these species. Significant changes in winter conditions, as well as during the breeding season, and an overall increase in annual temperatures are likely reasons for a significant increase in the number of birds in winter. Greater winter survival, an increase in the survival rate of fledglings and juveniles during the summer, and later onset of winter, are very important determinants of the winter population. Our findings show that numbers of birds in late winter are related to the severity of winter conditions. Our data do not support conclusions that the populations of forest bird species have decreased due to climate change.

Changes in habitat suitability influence non-breeding distribution of waterbirds in central Europe

Article

Nov 2017

Waterbird species have different requirements with respect to their non-breeding areas, aiming to survive and gain condition during the non-breeding period. Selection of non-breeding areas could change over time and space driven by climate change and species habitat requirements. To help explain the mechanism shaping non-breeding area selection, we provide site-specific analyses of distributional changes in wintering waterbirds in central Europe; located at the centre of their flyways. We use wintering waterbirds as a highly dynamic model group monitored over a long-time scale of 50 years (1966–2015). We identified species habitat requirements and changes in habitat use at the level of 733 individual non-breeding (specifically wintering) sites for 12 waterbird species using citizen-science monitoring data. We calculated site-specific mean numbers and estimated site-specific trends in numbers. The site-specific approach revealed a general effect of mean winter temperature of site (seven out of 12 species), wetland type (all species) and land cover (all species) on site-specific numbers. We found increasing site-specific trends in numbers in the northern and/or eastern part of the study area (Mute Swan Cygnus olor, Eurasian Teal Anas crecca, Common Pochard Aythya ferina, Great Cormorant Phalacrocorax carbo and Eurasian Coot Fulica atra). Common Merganser Mergus merganser, Great Cormorant, Grey Heron Ardea cinerea, Common Pochard, Eurasian Coot and Common Moorhen increased their site-specific numbers on standing waters with traditionally low fish stock. The site-specific dynamics of bird numbers helped us to identify general preference for sites reducing winter harshness (warmer areas, running waters and more wetlands in the site vicinity); as well as indicating climate-driven changes in spatial use of wintering sites (northern/north-eastern range changes and changes in preference for industrial waters). This fine-scale (site-specific) approach can reveal large-scale range and distribution shifts driven by climate and environmental changes regardless of the availability of large-scale datasets. This article is protected by copyright. All rights reserved.

Spatial distribution and long-term abundance dynamic of a jay and a three-toed woodpecker in forests of the Republic of Tatarstan ПРОСТРАНСТВЕННОЕ РАСПРЕДЕЛЕНИЕ И МНОГОЛЕТНЯЯ ДИНАМИКА ЧИСЛЕННОСТИ СОЙКИ И ТРЕХПАЛОГО ДЯТЛА В ЛЕСАХ РЕСПУБЛИКИ ТАТАРСТАН

Article

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May 2017

The article shows the results of the study of a jay and a three-toed woodpecker distribution in 54 sites of forests of the Republic of Tatarstan. This study an- alyzed the long-term abundance dynamics of a three- toed woodpecker and a jay. The main environmental factors that influence the number of the birds have been revealed. Keywords: a jay; a three-toed woodpecker; lati- tude and longitude location; long-term abundance dynamics; environmental factors.

Bird winter population dynamics at the eastern edge of Europe

Article

Full-text available

Mar 2017

Askeyev, O., A. Askeyev & I. Askeyev 2017: Bird winter population dynamics at the eastern edge of Europe. Vogelwelt 137: 134–142. Since the 1970s, the climate in Europe has undergone rapid changes, with the greatest observed changes occurring during the winter. Significant changes in winter conditions have also been observed in the majority of Russian regions. However, in our view, the role played by increases in winter temperature in the dynamics of bird populations is still poorly known. The aim of our research was to analyze data on the winter density of 10 largely sedentary bird species. The material for our research was bird censuses collected using transect counts during a 25 year period from 1991 to 2015. Great Tit, Blue Tit, Willow Tit, Marsh Tit, Crested Tit, Nuthatch, Treecreeper and Goldcrest showed a significant increase in abundace. None of the 10 species showed a decrease in abundance. The main factors correlated with population growth were increases in annual temperature, winter temperature and temperature during the preceding breeding season. In Finland and Sweden, similar abundance dynamics have been observed for some of these species but population trends for Willow Tit, Goldcrest and Crested Tit in this study differed markedly from observations in other parts of Europe. This suggests that climatic changes can have a rapid impact on the size of bird populations and that population trends observed in Eastern Europe may differ significantly from those in the western part of the continent. The inclusion of data on population dynamics from a larger sample of European regions would help to more accurately assess the response of birds to climate change. Keywords: winter bird density, changes, temperature, European Russia

Are winter and breeding bird communities able to track rapid climate change? Lessons from the high North

Article

Dec 2016

Aim Climate change is a major threat to biodiversity and a major factor underlying observed shifts in species distribution, abundance and phenology. Research effort on climate change impacts on species has often been based on single‐species studies focused on a single season, typically the breeding season, of species life cycles. We test how well winter and breeding bird communities are able to track climate change. Location Finland. Methods We use a dataset consisting of bird counts from the winter and the breeding period spanning over four decades and a 1000 km latitudinal gradient across Finland, Northern Europe. We use the bird count data in combination with a species‐specific average temperature index to derive a functional index, the Community Temperature Index ( CTI ), which provides a measure of the relative temperature average of a community. Results We show that the CTI of the winter bird community ( CTI w ) in Finland has increased significantly over the past four decades, but not as fast as the average winter temperature. Across Finland, CTI w decreased towards the north and the east of the country and increased with increasing temperature. Further, we show that change in CTI through time (from 1970s–1980s to 2000–2014) was similar between the winter and the breeding communities. Main conclusions Overall, our results suggest that while the winter and breeding bird communities are, to a certain level, tracking increasing temperatures, the magnitude of temperature change is multiple times greater than the magnitude of community shifts. This is particularly true for the winter birds that are facing the most rapid temperature shifts. Our findings shed light on the importance of assessing and eventually addressing the effects of rapid climate warming beyond the breeding season of species life cycles.

A basic Finnish climate data set 1961-200 - description and illustrations

Technical Report

Full-text available

Aug 2005

Research related to the impact of and adaptation to climate change requires a comprehensive set of climate data. Both scenarios of future climate as well as records of past climate are needed. As a part of the FINADAPT research project, the Finnish Meteorological Institute has produced a set of climate data for the requirements of various research groups. The data set consists of daily mean temperature and daily precipitation data interpolated onto a 10*10 km grid. Interpolation scheme works well with daily temperatures. However spatial variation of daily precipitation is smoothed. This leads to about 17% systematic underestimation in the long-term annual average. In addition to these interpolated data, measurements obtained from five observing stations were also included in the data set. The station data consist of daily precipitation, mean, maximum and minimum temperatures, air humidity, wind speed, snow depth, global radiation, sunshine hours and potential evaporation, as well as growing season temperature and precipitation sum information. The aim of this report is to describe the data set, give some examples of the use of these data and to be literature that can be referred to when the data are used in scientific articles

Population trends in wintering landbirds in the Netherlands 1980-2006: Effects of region, habitat and migratory behaviour

Article

Full-text available

Jan 2008

Starting in 1978, Point Transect Counts of wintering birds form one of the oldest monitoring schemes for birds in the Netherlands. They are organised by SOVON in close collaboration with Statistics Netherlands and entirely conducted by volunteer birdwatchers. The census alms to monitor changes in wintering populations in mainly terrestrial birds (waterbirds are monitored with a specific waterbird monitoring scheme). Fieldwork is highly standardised and includes 20 point-counts of exactly five minutes at selected points along a fixed transect, chosen by the observer. Points have to be situated at least 500 m apart in open landscape and 250 m in wooded areas. Today, about 400 transects are covered annually, well spread over habitats within the Netherlands (figs. 1, 2). Trend calculations, both at regional and national scale, have been carried out with theTRIM package (see table 1 for trend classification) for 64 terrestrial bird species. This paper presents data of Point Transect Counts in 1980-2006, with special reference to differences between the high and low grounds within the Netherlands, i.e. between the pleistocene (with predominantly sandy soils) eastern and holocene (with predominantly clay and peat soils) northern and western parts of the country (fig. 3). General results are summarised in table 3 and figs. 5-8. Sedentary species and partial migrants inhabiting woodlands have generally increased since 1980. They have benefited from both the increased frequency of mild winters (improved winter survival) and the extension and maturation of forest plantations in the lower western and northern parts of the country (increase of suitable habitats). In woodlands in the traditional breeding areas at the high grounds, numbers remained fairly stable for most species. Winter visitors and sedentary species inhabiting other habitats on the other hand slightly decreased on average. In farmland, natural habitats and urban areas, differences between Pleistocene and Holocene regions are less striking, although intriguing differences do occur (Eurasian Collared Dove, Common Magpie). In a few species recent changes in breeding populations abroad (Hen Harrier, Grey Wagtail) and changed migratory strategies seem to affect numbers wintering in The Netherlands (decline in wintering Rook).

Velocity of density shifts in Finnish landbird species depends on their migration ecology and body mass

Article

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May 2016
OECOLOGIA

A multitude of studies confirm that species have changed their distribution ranges towards higher elevations and towards the poles, as has been predicted by climate change forecasts. However, there is large interspecific variation in the velocity of range shifts. From a conservation perspective, it is important to understand which factors explain variation in the speed and the extent of range shifts, as these might be related to the species’ extinction risk. Here, we study shifts in the mean latitude of occurrence, as weighted by population density, in different groups of landbirds using 40 years of line transect data from Finland. Our results show that the velocity of such density shifts differed among migration strategies and increased with decreasing body size of species, while breeding habitat had no influence. The slower velocity of large species could be related to their longer generation time and lower per capita reproduction that can decrease the dispersal ability compared to smaller species. In contrast to some earlier studies of range margin shifts, resident birds and partial migrants showed faster range shifts, while fully migratory species were moving more slowly. The results suggest that migratory species, especially long-distance migrants, which often show decreasing population trends, might also have problems in adjusting their distribution ranges to keep pace with global warming.

Changes in migration

Article

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Jan 2010

Inter-annual variation and long-term trends in proportions of resident individuals in partially migratory birds

Article

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Dec 2015
J ANIM ECOL

Partial migration – a part of a population migrates and another part stays resident year‐round on the breeding site – is probably the most common type of migration in the animal kingdom, yet it has only lately garnered more attention. Theoretical studies indicate that in partially migratory populations, the proportion of resident individuals (PoR) should increase in high latitudes in response to the warming climate, but empirical evidence exists for few species. We provide the first comprehensive overview of the environmental factors affecting PoR and the long‐term trends in PoR by studying 27 common partially migratory bird species in Finland. The annual PoR values were calculated by dividing the winter bird abundance by the preceding breeding abundance. First, we analysed whether early‐winter temperature, winter temperature year before or the abundance of tree seeds just before overwintering explains the interannual variation in PoR. Secondly, we analysed the trends in PoR between 1987 and 2011. Early‐winter temperature explained the interannual variation in PoR in the waterbirds (waterfowl and gulls), most likely because the temperature affects the ice conditions and thereby the feeding opportunities for the waterbirds. In terrestrial species, the abundance of seeds was the best explanatory variable. Previous winter's temperature did not explain PoR in any species, and thus, we conclude that the variation in food availability caused the interannual variation in PoR. During the study period, PoR increased in waterbirds, but did not change in terrestrial birds. Partially migratory species living in physically contrasting habitats can differ in their annual and long‐term population‐level behavioural responses to warming climate, possibly because warm winter temperatures reduce ice cover and improve the feeding possibilities of waterbirds but do not directly regulate the food availability for terrestrial birds.

Population trends of common breeding forest birds in southern Finland are consistent with trends in forest management and climate change

Article

Full-text available

Dec 2015
ORNIS FENNICA

In Finland, modern forestry has caused the gross modification of native forest habitats and a loss of biological diversity due to intensive management regimes. Although less than 1% of the old-growth forest area remains in southern Finland, the effects of forestry on bird population long-term trends have not been comprehensively studied in this area. To fill this knowledge gap, we analysed 30 years of monitoring data of 32 common forest breeders in southern Finland. For each species, we fitted piecewise log-linear trends in two segments: 1984–1998 (period 1) and 1999–2013 (period 2). The estimated trends were analysed in relation to the species-specific habitat preferences, average tree height preference, migratory strategy, and latitudinal distribution. The trends turned on average more negative in period 2 compared to period 1, but the between-species variation in this change was not explained by any of the predictors. For the whole study period, species with a preference for late successional and nutrient-poor habitats (mostly found in northern latitudes) showed more negative population trends. In addition, trends changed on average –3%/ 500 km latitude.We further developed three summarizing multi-species indices, most of which should be useful for monitoring the general state of breeding forest bird communities in southern Finland. Our results suggest that bird communities are shaped by both a loss of mature forests and by climate warming. The decline of birds preferring native forests, reflected by the mature forest index, could undoubtedly change with an improvement of the conservation effectiveness in southern Finland.

Seeking explanations for recent changes in abundance of wintering Eurasian Wigeon (Anas penelope) in northwest Europe

Article

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Mar 2016
ORNIS FENNICA

We analysed annual changes in abundance of Eurasian Wigeon (Anas penelope ) derived from mid-winter International Waterbird Census data throughout its northwest European flyway since 1988 using log-linear Poisson regression modelling. Increases in abundance in the north and east of the wintering range (Norway, Sweden, Denmark, Germany, Swit - zerland), stable numbers in the central range (Belgium, Netherlands, UK and France) and declining abundance in the west and south of the wintering range (Spain and Ireland) sug - gest a shift in wintering distribution consistent with milder winters throughout the range. However, because over 75% of the populatio n of over 1 million individuals winters in Belgium, the Netherlands, UK and France, there was no evidence for a major movement in the centre of gravity of the wintering distribution. Between-winter changes in overall flyway abundance were highly si gnificantly positively correlated ( P = 0.003) with repro- ductive success measured by age ratios in Danish hunter wing surveys and less strongly and inversely correlated (P = 0.05) with mean January temperatures in the centre of the wintering range, suggesting that winter severity may also contribute to influence survival. However, adding winter severity to a model p redicting population size based on annual reproductive success alone did not contribute to more effect ively modelling the observed changes in population size. Patterns in annual reproductive success seem therefore to largely explain the recent dynamics in popul ation size of northwest European Wigeon. Summer NAO significantly and positively explai ned 27% of variance in annual breeding success. Other local factors such as eutrophication of breeding sites and changes in preda- tion pressure undoubtedly contribute to change s in the annual production of young and differences in hunting pressure as well as winter severity affect annual survival rates. However, it seems likely that the observed flyway population trend since 1988 has been mostly influenced by climate effects on the breeding grounds affecting reproductive suc- cess and marginally on the winter quarters affecting survival. We urge improved demo- graphic monitoring of the population to be tter assess annual survival and reproductive success. We also recommend development of an adaptive management framework to re- move uncertainties in our knowledge of Wigeon population dynamics as information is forthcoming to better inform management, es pecially to attempt to harmonise the harvest with annual changes in demography to ensure sustainable exploitation of this important quarry species now and in the future.

Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem

Article

Full-text available

Sep 2015
PLOS ONE

Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf). Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf Ecosystem with potential to impact fisheries and other ecosystem services.

Global biodiversity: indicators of recent declines

Article

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Jan 2010

Climate-driven changes in winter abundance of a migratory waterbird in relation to EU protected areas

Article

Full-text available

May 2015
DIVERS DISTRIB

Aim Species are responding to climate change by changing their distributions, creating debate about the effectiveness of existing networks of protected areas. As a contribution to this debate, we assess whether regional winter abundances and distribution of the Smew Mergellus albellus , a migratory waterbird species listed on Annex I ( EU Birds Directive) that overwinters exclusively in European wetlands, changed during 1990–2011, the role of global warming in driving distributional changes and the effectiveness of the network of Special Protection Areas ( SPA s, EU Birds Directive) in the context of climate change. Location Europe. Methods We used site‐specific counts (6,883 sites) from 16 countries covering the entire flyway to estimate annual abundance indices and trends at country, region (north‐eastern, central and south‐western) and flyway scales, inside and outside SPA s. We fitted autoregressive models to assess the effect of winter temperature on the annual abundance indices whilst accounting for autocorrelation. Results The Smew wintering distribution shifted north‐eastwards in Europe in accordance with the predictions of global warming, with increasing numbers in the north‐eastern region and declines in the central region. Trends in wintering numbers were more positive in SPA s on the north‐eastern and south‐western part of the flyway. However, a large proportion of the wintering population remains unprotected in north‐eastern areas outside of the existing SPA network. Main conclusions SPA s accommodated climate‐driven abundance changes in the north‐eastern region of the wintering distribution by supporting increasing numbers of Smew in traditional and newly colonized areas. However, we highlight gaps in the current network, suggesting that urgent policy responses are needed. Given rapid changes in species distributions, we urge regular national and international assessments of the adequacy of the EU Natura 2000 network to ensure coherence in site‐safeguard networks for this and other species.

TRIM 3 manual (TRends and Indices for Monitoring data)

Technical Report

Full-text available

Jan 2005

Trends in the average temperature in Finland, 1847–2013

Article

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Dec 2014

The change in the mean temperature in Finland is investigated with a dynamic linear model in order to define the sign and the magnitude of the trend in the temperature time series within the last 166 years. The data consists of gridded monthly mean temperatures. The grid has a 10 km spatial resolution, and it was created by interpolating a homogenized temperature series measured at Finnish weather stations. Seasonal variation in the temperature and the autocorrelation structure of the time series were taken account in the model. Finnish temperature time series exhibits a statistically significant trend, which is consistent with human-induced global warming. The mean temperature has risen very likely over 2 °C in the years 1847–2013, which amounts to 0.14 °C/decade. The warming after the late 1960s has been more rapid than ever before. The increase in the temperature has been highest in November, December and January. Also spring months (March, April, May) have warmed more than the annual average, but the change in summer months has been less evident. The detected warming exceeds the global trend clearly, which matches the postulation that the warming is stronger at higher latitudes.

Impacts of trichomonosis epidemics on Greenfinch Chloris chloris and Chaffinch Fringilla coelebs populations in Finland

Article

Full-text available

Apr 2013
IBIS

Population consequences of parasites in wild birds are rarely documented. One exception is the decline of British finch populations due to an epidemic caused by the protozoan parasite Trichomonas gallinae. Finch trichomonosis has recently spread from the UK to northern Europe, but its consequences for local finch populations have not been studied. We assessed the extent to which the trichomonosis epidemic affected the Finnish population sizes of European Greenfinch Chloris chloris, Common Chaffinch Fringilla coelebs and a control species, Great Tit Parus major, and the body condition of Greenfinches. The disease was first documented in Finland in 2008 and epidemics were observed mainly in southwestern Finland. Greenfinches showed a significant decline of 47% in breeding numbers and 65% in wintering numbers in southern Finland during 2006–2010. Breeding Chaffinch numbers showed a slight decline (4%) during the same study period that was significant only in central Finland. Great Tit did not show a significant change in breeding numbers. During the initial disease epidemic the body condition of all demographic groups of Greenfinches decreased equally, which suggests that the disease was not selective in respect of age or sex. There were no encounters of Finnish-ringed Greenfinches or Chaffinches in the UK, which could indicate that the parasite has not necessarily been transferred directly from the UK, but perhaps by migrants from Sweden and Germany.

Population trends in boreal birds: Continuing declines in agricultural, northern, and long-distance migrant species

Article

Full-text available

Dec 2013
BIOL CONSERV

When many environmental changes take place simultaneously, one of the first challenges for conservation efforts is to identify the species and environments that are in the most need of conservation measures. We studied whether there are differences in the population growth trends of 94 boreal bird species according to their migration strategies, breeding distributions (northern or southern), or breeding habitats. To this end, we examined recent trends in bird census data covering >1000 km along a north–south transect in Finland, from the deciduous forests on the southern coast through the boreal taiga forest to the alpine fell area in the north. Our results show that long-distance migrants (species wintering in western or eastern Africa or Asia), northern species, and species living in agricultural environments are in decline in north-eastern Europe. The results were the same for both the long-term (27 years; 1986–2012) and the short-term (12 years, the most recent reporting period of the EU bird directive; 2001–2012) data set. Additionally, species breeding mainly in urban/sub-urban environments, coniferous forests, or wetlands showed negative growth trends, especially over the short-term. These results provide updated information that can be used to determine the targets of conservation efforts focused on Northern Palaearctic birds. Several different conservation measures may be needed to help these populations, ranging from protecting habitat in the migration and wintering grounds to changing climate and agricultural policies at a national and/or international level. In addition, further research is needed to identify the particular mechanisms underlying the population trends.

Climate-driven changes in Northeastern US butterfly communities

Article

Full-text available

Feb 2013

Climate warming is expected to change the distribution and abundance of many species. Range shifts have been detected in a number of European taxa for which long-term government-initiated or organized-survey data are available. In North America, well-organized long-term data needed to document such shifts are much less common. Opportunistic observations made by citizen scientist groups may be an excellent alternative to systematic surveys. From 1992 to 2010, 19,779 butterfly surveys were made by amateur naturalists in Massachusetts, a geographically small state located at the convergence of northern and southern bioclimatic zones in eastern North America. From these data, we estimated population trends for nearly all butterfly species (100 of 116 species present) using list-length analysis. Population trajectories indicate increases of many species near their northern range limits and declines in nearly all species (17 of 21) near their southern range limits. Certain life-history traits, especially overwintering stage, were strongly associated with declines. Our results suggest that a major, climate-induced shift of North American butterflies, characterized by northward expansions of warm-adapted and retreat of cold-adapted species, is underway.

Extent of recent polewards range margin shifts in Finnish birds depends on their body mass and feeding ecology

Article

Full-text available

Jan 2008
ORNIS FENNICA

Jon E Brommer

Global warming would predict that, all else being equal, species should shift their range margins polewards, and that a failure to do so could be detrimental for a population. A polewards range margin shift has been documented previously in the Finnish avifauna. Here, I showed that the polewards range margin shift of 116 Southern Finnish bird species was larger for small-bodied species and differed according to their feeding ecology, but not to their migration ecology. Species foraging in wet habitats had experienced strong range margin shifts as compared with other feeding ecologies. For 53 species, population trends for 1983-2005 were available. I found no evidence that those feeding ecological groups that showed a relatively small shift in range margin had experienced low popula- tion growth or a population decline. Instead, I found some evidence that the long-term trend in population numbers varied across migration ecologies after correcting for changes in their Finnish breeding range. The results suggest that those processes that cause a shift in the range margin of birds are not involved in the recent changes in bird abundances.

Rapid climate driven shifts in wintering distributions of three common waterbird species

Article

Full-text available

Mar 2013

Climate change is predicted to cause changes in species distributions and several studies report margin range shifts in some species. However, the reported changes rarely concern a species' entire distribution and are not always linked to climate change. Here we demonstrate strong north-eastwards shifts in the centres of gravity of the entire wintering range of three common waterbird species along the North-West Europe flyway during the past three decades. These shifts correlate with an increase of 3.8 °C in early winter temperature in the north-eastern part of the wintering areas, where bird abundance increased exponentially, corresponding with decreases in abundance at the south-western margin of the wintering ranges. This confirms the need to re-evaluate conservation site safeguard networks and associated biodiversity monitoring along the flyway, as new important wintering areas are established further north and east, and highlights the general urgency of conservation planning in a changing world. Range shifts in wintering waterbirds may also affect hunting pressure, which may alter bag sizes and lead to population level consequences. © 2013 Blackwell Publishing Ltd.

Key conservation issues for migratory land- and waterbird species on the world's major flyways

Article

Full-text available

Sep 2008
BIRD CONSERV INT

An estimated 19% of the world's 9,856 extant bird species are migratory, including some 1,600 species of land- and waterbirds. In 2008, 11% of migratory land- and waterbirds were classed by BirdLife International as threatened or near-threatened on the IUCN Red List. Red List indices show that these migrants have become more threatened since 1988, with 33 species deteriorating and just six improving in status. There is also increasing evidence of regional declines. Population trend data show that more Nearctic–Neotropical migrants have declined than increased in North America since the 1980s, and more Palearctic–Afrotropical migrants breeding in Europe declined than increased during 1970–2000. Reviews of the status of migratory raptors show unfavourable conservation status for 51% of species in the African–Eurasian region (in 2005), and 33% of species in Central, South and East Asia (in 2007). Land-use change owing to agriculture is the most frequently cited threat affecting nearly 80% of all threatened and near-threatened species. However, while agricultural intensification on the breeding grounds is often proposed as the major driver of declines in Palearctic–Afrotropical migrants, some species appear to be limited by the quantity and quality of available habitat in non-breeding areas, notably the drylands of tropical Africa. Forest fragmentation in breeding areas has contributed to the declines of Nearctic–Neotropical migrants with deforestation in non-breeding areas another possible factor. Infrastructure development including wind turbines, cables, towers and masts can also be a threat. Over-harvesting and persecution remain serious threats, particularly at key migration locations. Climate change is affecting birds already, is expected to exacerbate all these pressures, and may also increase competition between migratory and non-migratory species. The conservation of migratory birds thus requires a multitude of approaches. Many migratory birds require effective management of their critical sites, and Important Bird Areas (IBAs) provide an important foundation for such action; however to function effectively in conserving migratory species, IBAs need to be protected and the coherence of the network requires regular review. Since many migratory species (c. 55%) are widely dispersed across their breeding or non-breeding ranges, it is essential to address the human-induced changes at the wider landscape scale, a very considerable challenge. Efforts to conserve migratory birds in one part of the range are less effective if unaddressed threats are reducing these species' populations and habitats elsewhere. International collaboration and coordinated action along migration flyways as a whole are thus key elements in any strategy for the conservation of migratory birds.

Poleward shifts of species' ranges associated with regional warming

Article

Full-text available

Jun 1999

Mean global temperatures have risen this century, and further warming is predicted to continue for the next 50-100 years. Some migratory species can respond rapidly to yearly climate variation by altering the timing or destination of migration, but most wildlife is sedentary and so is incapable of such a rapid response. For these species, responses to the warming trend should be slower, reflected in poleward shifts of the range. Such changes in distribution would occur at the level of the population, stemming not from changes in the pattern of indivduals' movements, but from changes in the ratios of extinctions to colonizations at the northern and southern boundaries of the range. A northward range shift therefore occurs when there is net extinction at teh southern boundary or net colonization at the northern boundary. However, previous evidence has been limited to a single species or to only a portion of the species' range. Here we provide the first large-scale evidence of poleward shifts in entire species' ranges. In a sample of 35 non-migratory European butterflies, 63% have ranges that have shifted to the north by 35-240 km during this century, and only 3% have shifted to the south.

Very high resolution interpolated climate surfaces of global land areas

Article

Full-text available

Dec 2005

We developed interpolated climate surfaces for global land areas (excluding Antarctica) at a spatial resolution of 30 arc s (often referred to as 1-km spatial resolution). The climate elements considered were monthly precipitation and mean, minimum, and maximum temperature. Input data were gathered from a variety of sources and, where possible, were restricted to records from the 1950-2000 period. We used the thin-plate smoothing spline algorithm implemented in the ANUSPLIN package for interpolation, using latitude, longitude, and elevation as independent variables. We quantified uncertainty arising from the input data and the interpolation by mapping weather station density, elevation bias in the weather stations, and elevation variation within grid cells and through data partitioning and cross validation. Elevation bias tended to be negative (stations lower than expected) at high latitudes but positive in the tropics. Uncertainty is highest in mountainous and in poorly sampled areas. Data partitioning showed high uncertainty of the surfaces on isolated islands, e.g. in the Pacific. Aggregating the elevation and climate data to 10 arc min resolution showed an enormous variation within grid cells, illustrating the value of high-resolution surfaces. A comparison with an existing data set at 10 arc min resolution showed overall agreement, but with significant variation in some regions. A comparison with two high-resolution data sets for the United States also identified areas with large local differences, particularly in mountainous areas. Compared to previous global climatologies, ours has the following advantages: the data are at a higher spatial resolution (400 times greater or more); more weather station records were used; improved elevation data were used; and more information about spatial patterns of uncertainty in the data is available. Owing to the overall low density of available climate stations, our surfaces do not capture of all variation that may occur at a resolution of 1 km, particularly of precipitation in mountainous areas. In future work, such variation might be captured through knowledge-based methods and inclusion of additional co-variates, particularly layers obtained through remote sensing.

Fahrig L.. Effects of Habitat Fragmentation on Biodiversity. Annu Rev Ecol Evol Syst 34: 487-515

Article

Full-text available

Nov 2003

Lenore Fahrig

The literature on effects of habitat fragmentation on biodiversity is huge. It is also very diverse, with different authors measuring fragmentation in different ways and, as a consequence, drawing different conclusions regarding both the magnitude and direction of its effects. Habitat fragmentation is usually defined as a landscape-scale process involving both habitat loss and the breaking apart of habitat. Results of empirical studies of habitat fragmentation are often difficult to interpret because (a) many researchers measure fragmentation at the patch scale, not the landscape scale and (b) most researchers measure fragmentation in ways that do not distinguish between habitat loss and habitat fragmentation per se, i.e., the breaking apart of habitat after controlling for habitat loss. Empirical studies to date suggest that habitat loss has large, consistently negative effects on biodiversity. Habitat fragmentation per se has much weaker effects on biodiversity that are at least as likely to be positive as negative. Therefore, to correctly interpret the influence of habitat fragmentation on biodiversity, the effects of these two components of fragmentation must be measured independently. More studies of the independent effects of habitat loss and fragmentation per se are needed to determine the factors that lead to positive versus negative effects of fragmentation per se. I suggest that the term "fragmentation" should be reserved for the breaking apart of habitat, independent of habitat loss.

Energy Constraints on Avian Distributions and Abundances

Article

Full-text available

Apr 1988

Terry L Root

Calculated the metabolic rate at the northern boundary of the distribution for 14 of 51 passerines known to have range boundaries associated with a particular average minimum January temperature isotherm. The northern boundary metabolic rate (NBMR) is 2.45 times the basal metabolic rate (BMR). The NBMR to BMR ratio shows little interspecific variation; the mean of this ratio is 2.49 (standard error ±0.07). This strong association between NBMR and BMR implies that the winter ranges of these 14 birds are restricted to areas where the energy needed to compensate for a colder environment is not greater than ~2.5 times the BMR. Body masses of 36 of the remaining 37 birds, those with their range limits associated with isotherms and without physiological measurements, were used to estimate the various physiological parameters. Even when using such crude estimates of these parameters, the approximation of the metabolic rate of individuals at the northern boundaries of their distributions was 2.65 times their BMR. Furthermore, high-density populations of 7 of the 14 species with accurately measured physiological parameters were limited to regions where homeostasis requires energy output of ≤2.13 times their BMR. The range of this scalar extends from 2.08-2.34. On a broad scale the winter ranges of a large number of passerines are thus limited by energy expenditures necessary to compensate for colder ambient temperatures. -from Author

Poleward shifts in the geographical ranges of butterfly species associated with global warming

Article

Jan 1999
NATURE

Population decline of the Siberian Tit (Poecile cinctus) in southern Norway and an assessment of possible causes

Article

Jul 2016
ORNIS FENNICA

The Siberian Tit (Poecile cinctus) is an old-growth forest specialist in the northern taiga. The Finnish population has declined dramatically due to logging. An isolated population occurs in southern Norway. This population was estimated at 1,000 pairs based on surveys in 1979-80, and the Siberian Tit constituted 9% of all individuals in the whole bird community and 64% of all tits in lichen-dominated pine forest. In 2011-12 we censused tit species (Paridae) along 292.5 km line transects at 51 sites in southern Norway with potential occurrence of Siberian Tit. We found that the Siberian Tit constituted only about 1% of all tit territories or individuals. Recensuses of two sites which had Siberian Tits in 1979-80 showed no presence in 2011. The overall distribution range appears to have contracted over the past 30 years, and we suggest that current population size is only 50-150 pairs. We suggest three possible causes (climate change, competition with other tit species, forestry) for why the population of Siberian Tits in southern Norway has declined. A prospective assessment of available evidence indicated that 1) there was no change in elevation of historical records spanning > 40 years, 2) Great Tits (Parus major) and Willow Tits (Poecile montanus) were now common in areas where they did not occur in 1979-80, 3) there was a large overlap in habitat selection of the Siberian Tit and three other tit species, 4) there was only a weak association of Siberian Tits with old-growth forest, and 5) previously occupied sites had generally not been affected by logging. Thus, we suggest that future studies of population decline of the Siberian Tit should focus in particular on competitive interactions with other tit species.

¿Cómo afectará el cambio climático a los parásitos y las enfermedades infecciosas de los animales acuáticos?

Article

Aug 2008
REV SCI TECH OIE

David J. Marcogliese

Migratory diversity predicts population declines in birds

Article

Jan 2016
ECOL LETT

Declines in migratory species are a pressing concern worldwide, but the mechanisms underpinning these declines are not fully understood. We hypothesised that species with greater within-population variability in migratory movements and destinations, here termed 'migratory diversity', might be more resilient to environmental change. To test this, we related map-based metrics of migratory diversity to recent population trends for 340 European breeding birds. Species that occupy larger non-breeding ranges relative to breeding, a characteristic we term 'migratory dispersion', were less likely to be declining than those with more restricted non-breeding ranges. Species with partial migration strategies (i.e. overlapping breeding and non-breeding ranges) were also less likely to be declining than full migrants or full residents, an effect that was independent of migration distance. Recent rates of advancement in Europe-wide spring arrival date were greater for partial migrants than full migrants, suggesting that migratory diversity may also help facilitate species responses to climate change.

Differences in shifts of wintering and breeding ranges lead to changing migration distances in European birds

Article

Sep 2016
J AVIAN BIOL

Studies on the impact of climate change on the distributions of bird species in Europe have largely focused on one season at time, especially concerning summer breeding ranges. We investigated whether migratory bird species show consistent range shifts over the past 55 years in both breeding and wintering areas or if these shifts are independent. We then analyzed whether patterns in changing migration distances of Finnish breeding birds could be explained by habitat use, phylogeny or body size. We used long-term datasets from the Finnish ringing centre to analyze the mean wintering latitudes of 29 species of Finnish breeding birds, then used breeding distribution data to make predictions as to whether certain species were migrating shorter or longer distances based on the comparative shifts in the wintering and breeding grounds. Our data reveal species-specific differences in changing migration distances. We show that for many species, long-term shifts in wintering ranges have not followed the same patterns as those in the breeding range, leading to differences in migration distances over time. We conclude that species are not adjusting predictably to climate change in their wintering grounds, leading to changing migration distances in some, but not all, species breeding in Finland. This research fills an important gap in the current climate change biology literature, focusing on individuals' entire life histories and revealing new complexities in range shift patterns. This article is protected by copyright. All rights reserved.

Europe and the middle east

Article

Nov 2014

J.-F. Drevet

After dealing with the initial fallout from the collapse of the Soviet Union and the disappearance of the "Iron Curtain", particularly in the Balkans and even today in Ukraine, the European Union now finds itself directly affected by proliferating conflicts and disorder on its south-eastern flank. With civil war in Syria, a jihadist offensive in Iraq and the possible emergence of an autonomous Kurdistan, the Middle East remains a powder keg. The roots of this situation go back into European history, and the way it develops in the future will have consequences for the "old continent" in terms of politics, economics and migration. This month, Jean-François Drevet devotes his column to the various Middle-Eastern hotspots that have significant implications for Ell foreign policy. As he stresses, there is hardly any other option than to intervene, but it is not easy either to say what form such intervention should take to stem the current tide of troubles or to agree on effective neighbourhood policies in such a context.

Model Selection and Multimodel Inference

Article

Jan 2004

This chapter gives results from some illustrative exploration of the performance of information-theoretic criteria for model selection and methods to quantify precision when there is model selection uncertainty. The methods given in Chapter 4 are illustrated and additional insights are provided based on simulation and real data. Section 5.2 utilizes a chain binomial survival model for some Monte Carlo evaluation of unconditional sampling variance estimation, confidence intervals, and model averaging. For this simulation the generating process is known and can be of relatively high dimension. The generating model and the models used for data analysis in this chain binomial simulation are easy to understand and have no nuisance parameters. We give some comparisons of AIC versus BIC selection and use achieved confidence interval coverage as an integrating metric to judge the success of various approaches to inference.

Global biodiversity: Indicators of recent declines

Article

Jan 2010

Agricultural intensification and the collapse of Europe's farmland bird populations

Article

Jan 2001

The populations of farmland birds in Europe declined markedly during the last quarter of the 20th century, representing a severe threat to biodiversity. Here, we assess whether declines in the populations and ranges of farmland birds across Europe reflect differences in agricultural intensity, which arise largely through differences in political history. Population and range changes were modelled in terms of a number of indices of agricultural intensity. Population declines and range contractions were significantly greater in countries with more intensive agriculture, and significantly higher in the European Union (EU) than in former communist countries. Cereal yield alone explained over 30% of the variation in population trends. The results suggest that recent trends in agriculture have had deleterious and measurable effects on bird populations on a continental scale. We predict that the introduction of EU agricultural policies into former communist countries hoping to accede to the EU in the near future will result in significant declines in the important bird populations there.

Continent-scale global change attribution in European birds - combining annual and decadal time scales

Article

Feb 2016

Species attributes are commonly used to infer impacts of environmental change on multiyear species trends, e.g. decadal changes in population size. However, by themselves attributes are of limited value in global change attribution since they do not measure the changing environment. A broader foundation for attributing species responses to global change may be achieved by complementing an attributes-based approach by one estimating the relationship between repeated measures of organismal and environmental changes over short time scales. To assess the benefit of this multiscale perspective, we investigate the recent impact of multiple environmental changes on European farmland birds, here focusing on climate change and land use change. We analyze more than 800 time series from 18 countries spanning the past two decades. Analysis of long-term population growth rates documents simultaneous responses that can be attributed to both climate change and land-use change, including long-term increases in populations of hot-dwelling species and declines in long-distance migrants and farmland specialists. In contrast, analysis of annual growth rates yield novel insights into the potential mechanisms driving long-term climate induced change. In particular, we find that birds are affected by winter, spring, and summer conditions depending on the distinct breeding phenology that corresponds to their migratory strategy. Birds in general benefit from higher temperatures or higher primary productivity early on or in the peak of the breeding season with the largest effect sizes observed in cooler parts of species' climatic ranges. Our results document the potential of combining time scales and integrating both species attributes and environmental variables for global change attribution. We suggest such an approach will be of general use when high-resolution time series are available in large-scale biodiversity surveys.

Areal precipitation and temperature in the Swedish Mountains - An evaluation from a hydrological perspective

Article

Jun 2000

Barbro Johansson

This paper presents an evaluation of three different methods for estimation of areal precipitation and temperature, with special emphasis on their applicability for runoff modelling in the Swedish mountains. All three methods estimate the areal values as a weighted mean of the observations at nearby meteorological stations. The weights are determined by: 1) a manual subjective selection of the most representative stations 3) inverse square distance weighting 4) optimal interpolation The methods were tested in an area with complex topography and precipitation gradients. The evaluation included comparison of areal estimates, verification against point observations and the water balance equation, and sensitivity analyses with respect to method parameters and network changes. The evaluation showed that for simple runoff modelling the subjective and optimal interpolation methods performed equally well, and considerably better than inverse-distance weighting. The evaluation also showed that none of the methods correctly described the spatial variation in precipitation and temperature in the investigated region. They are thus not directly applicable for non-routine modelling applications where the estimation of runoff is not the sole objective. All methods proved to be sensitive to the selection of parameter values, which pointed to possible improvements of the estimates. The optimal interpolation method seemed to be the least sensitive to changes in the meteorological network.

The Migration Ecology of Birds

Article

Jan 2007

Ian Newton

This book presents an up-to-date, detailed and thorough review of the most fascinating ecological findings of bird migration. It deals with all aspects of this absorbing subject, including the problems of navigation and vagrancy, the timing and physiological control of migration, the factors that limit their populations, and more. Author, Ian Newton, reveals the extraordinary adaptability of birds to the variable and changing conditions across the globe, including current climate change. This adventurous book places emphasis on ecological aspects, which have received only scant attention in previous publications. Overall, the book provides the most thorough and in-depth appraisal of current information available, with abundant tables, maps and diagrams, and many new insights. Written in a clear and readable style, this book appeals not only to migration researchers in the field and Ornithologists, but to anyone with an interest in this fascinating subject. * Hot ecological aspects include: various types of bird movements, including dispersal and nomadism, and how they relate to food supplies and other external conditions * Contains numerous tables, maps and diagrams, a glossary, and a bibliography of more than 2,700 references * Written by an active researcher with a distinguished career in avian ecology, including migration research.

Birds and Climate Change: Impacts and Conservation Responses

Article

Jan 2012

From the red grouse to the Ethiopian bush-crow, bird populations around the world can provide us with vital insights into the effects of climate change on species and ecosystems. They are among the best studied and monitored of organisms, yet many are already under threat of extinction as a result of habitat loss, overexploitation and pollution. Providing a single source of information for students, scientists, practitioners and policy-makers, this book begins with a critical review of the existing impacts of climate change on birds, including changes in the timing of migration and breeding and effects on bird populations around the world. The second part considers how conservationists can assess potential future impacts, quantifying how extinction risk is linked to the magnitude of global change and synthesising the evidence in support of likely conservation responses. The final chapters assess the threats posed by efforts to reduce the magnitude of climate change.

Drivers of climate change impacts on bird communities

Article

Mar 2015
J ANIM ECOL

Climate change is reported to have caused widespread changes to species’ populations and ecological communities. Warming has been associated with population declines in long‐distance migrants and habitat specialists, and increases in southerly distributed species. However, the specific climatic drivers behind these changes remain undescribed. We analysed annual fluctuations in the abundance of 59 breeding bird species in England over 45 years to test the effect of monthly temperature and precipitation means upon population trends. Strong positive correlations between population growth and both winter and breeding season temperature were identified for resident and short‐distance migrants. Lagged correlations between population growth and summer temperature and precipitation identified for the first time a widespread negative impact of hot, dry summer weather. Resident populations appeared to increase following wet autumns. Populations of long‐distance migrants were negatively affected by May temperature, consistent with a potential negative effect of phenological mismatch upon breeding success. There was evidence for some nonlinear relationships between monthly weather variables and population growth. Habitat specialists and cold‐associated species showed consistently more negative effects of higher temperatures than habitat generalists and southerly distributed species associated with warm temperatures. Results suggest that previously reported changes in community composition represent the accumulated effects of spring and summer warming. Long‐term population trends were more significantly correlated with species’ sensitivity to temperature than precipitation, suggesting that warming has had a greater impact on population trends than changes in precipitation. Months where there had been the greatest warming were the most influential drivers of long‐term change. There was also evidence that species with the greatest sensitivity to extremes of precipitation have tended to decline. Our results provide novel insights about the impact of climate change on bird communities. Significant lagged effects highlight the potential for altered species’ interactions to drive observed climate change impacts, although some community changes may have been driven by more immediate responses to warming. In England, resident and short‐distance migrant populations have increased in response to climate change, but potentially at the expense of long‐distance migrants, habitat specialists and cold‐associated species.

Current population trends mirror forecasted changes in climatic suitability for Swedish breeding birds

Article

Feb 2013

Capsule Swedish breeding bird species that are predicted to experience a more suitable climate by 2050 are currently increasing in numbers. Aims To test, for a large set of breeding birds, if recent population trends mirror the changes in predicted climatic suitability across the Swedish distribution range, and to test if considering natal dispersal improves the fit of the predictive models. Methods Recent decadal population trends of 131 species of birds breeding in Sweden were compared to forecasted change in their future national distribution range by 2050, as simulated by suitability distribution models using climate and natal dispersal scenarios. Two other potential predictors of recent demographic trends are controlled for - namely habitat specialization and generation time. Results The 1998-2009 population trends were positively correlated with predicted changes in distribution range. Thus, forecasted changes in climatic suitability predict recent population trends. Accounting for the species-specific natal dispersal provided only a slightly better fit. Conclusion Recent climate change has affected the population size of Swedish breeding birds. Climatic suitability models can be an efficient tool for predicting the impacts of climate change on the abundance of birds.

Impacts of climate and land-use change on wintering bird populations in Finland

Article

Sep 2014
J AVIAN BIOL

Few studies have covered both the effects of climate and land-use change on animal populations under a single framework. Besides, the scarce multi-species studies conducted have focused on breeding data, and there is little information published on changes in wintering populations. Here, we relate the pattern of long-term temporal trends of wintering bird populations in Finland, north Europe, to covariates associated with climate and land-use change. Finnish wintering populations have been monitored using ca 10 km winter bird census routes (> 420 routes counted annually) during 1959–2012. Population trends of 63 species were related to migratory strategy, urbanity, and thermal niche measured as species-specific centre of gravity of the wintering distribution. Waterbird trends have shown a marked increase compared to landbirds. Among landbirds, forest species have suffered severe declines, whereas urban species have considerably increased in their wintering numbers. To follow up these results, we produced three multi-species indices (for waterbirds, forest and urban species, respectively), which can improve our ability to detect and monitor the specific consequences of climate change and changes in land-use, but at the same time act as a feedback to track the conservation status of the species. Our results suggest that waterbirds are responding to climate change, given their dependence on open water and the correlation with early-winter temperature over the last decades. On the other hand, we believe trends of landbirds have been mainly driven by human-induced land-use changes. While urban species have likely benefited from the increase of supplementary feeding, forest species have probably suffered from the loss of native habitats.

Rapid changes in bird community composition at multiple spatial scales in response to recent climate change

Article

Mar 2013
ECOGRAPHY

Although climate change is acknowledged to affect population dynamics and species distribution, details of how community composition is affected are still lacking. We investigate whether ongoing changes in bird community composition can be explained by contemporary changes in summer temperatures, using four independent long-term bird census schemes from Sweden (up to 57 yr); two at the national scale and two at local scales. The change in bird community composition was represented by a community temperature index (CTI) that reflects the balance in abundance between low- and high-temperature dwelling species. In all schemes, CTI tracked patterns of temperature increase, stability or decrease remarkably well, with a lag period of 1–3 yr. This response was similar at both the national and local scale. However, the communities did not respond fast enough to cope with temperature increase, suggesting that community composition lags behind changes in temperature. The change in CTI was caused mainly by changes in species’ relative abundances, and less so by changes in species composition. We conclude that ongoing changes in bird community structure are driven to a large extent by contemporary changes in climate and that CTI can be used as a simple indicator for how bird communities respond.

Climate Change and Birds

Article

Jan 2011

Anders Pape Moller

The decline of Afro-Paleartic migrants and an assessment of potential causes

Article

Jan 2014
IBIS

There is compelling evidence that Afro-Palaearctic (A-P) migrant bird populations have declined in Europe in recent decades, often to a greater degree than resident or short-distance migrants. There appear to have been two phases of decline. The first in the 1960s–1970s, and in some cases into the early 1980s, largely affected species wintering predominantly in the arid Sahelian zone, and the second since the 1980s has mostly affected species wintering in the humid tropics and Guinea forest zone. Potential drivers of these declines are diverse and are spread across and interact within the migratory cycle. Our knowledge of declining species is generally better for the breeding than the non-breeding parts of their life cycles, but there are significant gaps in both for many species. On the breeding grounds, degradation of breeding habitats is the factor affecting the demography of the largest number of species, particularly within agricultural systems and woodland and forests. In the non-breeding areas, the interacting factors of anthropogenic habitat degradation and climatic conditions, particularly drought in the Sahel zone, appear to be the most important factors. Based on our synthesis of existing information, we suggest four priorities for further research: (1) use of new and emerging tracking technologies to identify migratory pathways and strategies, understand migratory connectivity and enable field research to be targeted more effectively; (2) undertake detailed field studies in sub-Saharan Africa and at staging sites, where we understand little about distribution patterns, habitat use and foraging ecology; (3) make better use of the wealth of data from the European breeding grounds to explore spatial and temporal patterns in demographic parameters and relate these to migratory pathways and large-scale patterns of habitat change and climatic factors; and (4) make better use of remote sensing to improve our understanding of how and where land cover is changing across these extensive areas and how this impacts A-P migrants. This research needs to inform and underpin a flyway approach to conservation, evaluating a suite of drivers across the migratory cycle and combining this with an understanding of land management practices that integrate the needs of birds and people in these areas.

Population Limitation In Birds

Article

Jan 1998

Ian Newton

The Danish Bird Migration Atlas

Article

Jan 2006

Population trends of European birds are correlated with characteristics of their climatic niche

Article

May 2009
GLOBAL CHANGE BIOL

Temperate species are projected to experience the greatest temperature increases across a range of modelled climate change scenarios, and climate warming has been linked to geographical range and population changes of individual species at such latitudes. However, beyond the multiple modelling approaches, we lack empirical evidence of contemporary climate change impacts on populations in broad taxonomic groups and at continental scales. Identifying reliable predictors of species resilience or susceptibility to climate warming is of critical importance in assessing potential risks to species, ecosystems and ecosystem services. Here we analysed long-term trends of 110 common breeding birds across Europe (20 countries), to identify climate niche characteristics, adjusted to other environmental and life history traits, that predict large-scale population changes accounting for phylogenetic relatedness among species. Beyond the now well-documented decline of farmland specialists, we found that species with the lowest thermal maxima (as the mean spring and summer temperature of the hottest part of the breeding distribution in Europe) showed the sharpest declines between 1980 and 2005. Thermal maximum predicted the recent trends independently of other potential predictors. This study emphasizes the need to account for both land-use and climate changes to assess the fate of species. Moreover, we highlight that thermal maximum appears as a reliable and simple predictor of the long-term trends of such endothermic species facing climate change.

Climate change causes rapid changes in the distribution and site abundance of birds in winter

Article

Jun 2008
GLOBAL CHANGE BIOL

Detecting coherent signals of climate change is best achieved by conducting expansive, long-term studies. Here, using counts of waders (Charadrii) collected from ca. 3500 sites over 30 years and covering a major portion of western Europe, we present the largest-scale study to show that faunal abundance is influenced by climate in winter. We demonstrate that the ‘weighted centroids’ of populations of seven species of wader occurring in internationally important numbers have undergone substantial shifts of up to 115 km, generally in a northeasterly direction. To our knowledge, this shift is greater than that recorded in any other study, but closer to what would be expected as a result of the spatial distribution of ecological zones. We establish that year-to-year changes in site abundance have been positively correlated with concurrent changes in temperature, but that this relationship is most marked towards the colder extremities of the birds' range, suggesting that shifts have occurred as a result of range expansion and that responses to climate change are temperature dependent. Many attempts to model the future impacts of climate change on the distribution of organisms, assume uniform responses or shifts throughout a species' range or with temperature, but our results suggest that this may not be a valid approach. We propose that, with warming temperatures, hitherto unsuitable sites in northeastern Europe will host increasingly important wader numbers, but that this may not be matched by declines elsewhere within the study area. The need to establish that such changes are occurring is accentuated by the statutory importance of this taxon in the designation of protected areas.

Population trends of widespread woodland birds in Europe

Article

Nov 2007
IBIS

We explore population trends of widespread and common woodland birds using data from an extensive European network of ornithologists for the period 1980–2003. We show considerable differences exist in the European trends of species according to the broad habitat they occupy and the degree to which they specialize in habitat use. On average, common forest birds are in shallow decline at a European scale; common forest birds declined by 13%, and common forest specialists by 18%, from 1980 to 2003. In comparison, populations of common specialists of farmland have declined moderately, falling on average by 28% from 1980 to 2003. These patterns contrast with that shown by generalist species whose populations have been roughly stable over the same period, their overall index increasing by 3%. There was some evidence of regional variation in the population trends of these common forest species. The most obvious pattern was the greater stability of population trends in Eastern Europe compared with other regions considered. Among common forest birds, long-distance migrants and residents have on average declined most strongly, whereas short-distance migrants have been largely stable, or have increased. There was some evidence to suggest that ground- or low-nesting species have declined more strongly on average, as have forest birds with invertebrate diets. Formal analysis of the species trends confirmed the influence of habitat use, habitat specialization and nest-site; the effects of region and migration strategy were less clear-cut. There was also evidence to show that year-to-year variation in individual species trends at a European scale was influenced by cold winter weather in a small number of species. We recommend that the species trend information provided by the new pan-European scheme should be used alongside existing mechanisms to review the conservation status of European birds. The analysis also allows us to reappraise the role of common forest bird populations as a potential barometer of wider forest health. The new indicator appears to be a useful indicator of the state of widespread European forest birds and might prove to be a useful surrogate for trends in forest biodiversity and forest health, but more work is likely to be needed to understand the interaction between bird populations and their drivers in forest.

Climate change leads to decreasing bird migration distance

Article

Aug 2009
GLOBAL CHANGE BIOL

Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season in the Netherlands between 1932 and 2004. Of the 24 species included in the analysis, we found in 12 a significant decrease of the distance to the wintering site. Species from dry, open areas shortened their distance the most, species from wet, open areas the least, while woodland species fall in between the other two habitats. The decline in migration distance is likely due to climate change, as migration distances are negatively correlated with the Dutch temperatures in the winter of recovery. With a shorter migration distance, species should be better able to predict the onset of spring at their breeding sites and this could explain the stronger advancement of arrival date found in several short distance species relative to long-distance migrants.

Shifting nonbreeding distribution of migratory fauna in relation to climate change

Article

Jan 2005
GLOBAL CHANGE BIOL

The distributions of eight out of nine common species of waders (Charadrii) overwintering on UK estuaries have changed in association with recent climate change. These birds represent a high proportion of various populations from breeding grounds as far apart as Greenland to the west to high-arctic Russia to the east. During warmer winters, smaller proportions of seven species wintered in south-west Britain. The distributions of the smaller species show the greatest temperature dependence. The opposite was found for the largest species and no relationship was found for a particularly site-faithful species. In north-west Europe, the winter isotherms have a broadly north to south alignment, with the east being colder than the west. The average minimum winter temperatures across the UK having increased by about 1.5°C since the mid-1980s, the temperatures on the east coast during recent winters have been similar to those of the west coast during the mid-1980s. On average, estuaries on the east and south coasts of Britain have muddier sediments than those on the west coast and thus support a higher biomass of the invertebrate prey of waders. We suggest that, with global climatic change, the advantage gained by waders wintering in the milder west to avoid cold weather-induced mortality is diminished. Consequently, more choose to winter in the east and thus benefit from better foraging opportunities. The implications of these results are considered in terms of a site-based approach to wildlife protection used in Europe and elsewhere.

Effects of Habitat Fragmentation on Biodiversity

Article

Nov 2002

Lenore Fahrig

Tracking of climatic niche boundaries under recent climate change

Article

Feb 2012
J ANIM ECOL

1. Global climate has changed significantly during the past 30 years and especially in northern temperate regions which have experienced poleward shifts in temperature regimes. While there is evidence that some species have responded by moving their distributions to higher latitudes, the efficiency of this response in tracking species’ climatic niche boundaries over time has yet to be addressed. 2. Here, we provide a continental assessment of the temporal structure of species responses to recent spatial shifts in climatic conditions. We examined geographic associations with minimum winter temperature for 59 species of winter avifauna at 476 Christmas Bird Count circles in North America from 1975 to 2009 under three sampling schemes that account for spatial and temporal sampling effects. 3. Minimum winter temperature associated with species occurrences showed an overall increase with a weakening trend after 1998. Species displayed highly variable responses that, on average and across sampling schemes, contained a strong lag effect that weakened in strength over time. In general, the conservation of minimum winter temperature was relevant when all species were considered together but only after an initial lag period (c. 35 years) was overcome. The delayed niche tracking observed at the combined species level was likely supported by the post1998 lull in the warming trend. 4. There are limited geographic and ecological explanations for the observed variability, suggesting that the efficiency of species’ responses under climate change is likely to be highly idiosyncratic and difficult to predict. This outcome is likely to be even more pronounced and time lags more persistent for less vagile taxa, particularly during the periods of consistent or accelerating warming. Current modelling efforts and conservation strategies need to better appreciate the variation, strength and duration of lag effects and their association with climatic variability. Conservation strategies in particular will benefit through identifying and maintaining dispersal corridors that accommodate diverging dispersal strategies and timetables.

Large‐scale climatic drivers of regional winter bird population trends

Abstract

No full-text available

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