Article

Illegal killing slows population recovery of a re-introduced raptor of high conservation concern – the Red Kite Milvus milvus

May 2010
Biological Conservation 143(5):1278-1286

DOI:10.1016/j.biocon.2010.03.002

Authors:

Jennifer Smart

The Royal Society for the Protection of Birds

Arjun Amar

Percy FitzPatrick Institute of African Ornithology

Innes Michael William Sim

Royal Society for the Protection of Birds

Show all 7 authorsHide

The re-introduction of extirpated species is a valuable conservation tool. Red kites Milvus milvus are declining over much of their European range and have been re-introduced to England and Scotland, following their extinction due to widespread human persecution during the 19th century. Considerable regional variation in population growth exists. This study aims to identify the proximate demographic and ultimate environmental constraints on red kites in north Scotland, a region with low population growth. Productivity in north Scotland was high compared to other Scottish and Welsh populations and equal to English populations with high population growth rates. In north Scotland, annual survival of wild-fledged birds was low for first-year birds compared to other Scottish populations and second-year survival declined over time. In north Scotland, 40% of 103 red kites found dead were killed illegally, mainly by direct poisoning. In the absence of illegal killing, we estimate that annual survival rates in wild red kites might increase from 0.37 to 0.54, 0.72 to 0.78 and 0.87 to 0.92 for first, second-year and adult birds respectively. Demographic rates from this study produce population trends that recapitulate observed trends for the north Scotland population (leading to a population of c40 pairs by 2006). Models in which the additive illegal killing mortality is excluded, predict a population trajectory and size (c300 pairs by 2006) very similar to that found in the Chilterns, a rapidly growing population (320 pairs in 2006) in south-east England re-introduced at the same time, but where rates of illegal killing are much lower. We conclude that illegal killing of red kites is the cause of poor population growth in north Scotland and the key challenge facing government is to find a way to eliminate this killing.

A CONFLICT WITH WINGS: UNDERSTANDING THE NARRATIVES, RELATIONSHIPS AND HIERARCHIES OF CONFLICTS OVER RAPTOR CONSERVATION AND GROUSE SHOOTING IN SCOTLAND

Thesis

Full-text available

Apr 2020

Disagreements over wild species and the management of natural resources are inevitable. However, they often serve as proxies for less visible, deep-rooted social and political conflicts that occur between multiple groups of human actors. Such issues can considerably hinder the objectives of conservation and sustainable environmental management, by damaging relationships and trust among stakeholders, influencing their perceptions of the situation and shaping their actions towards the species and/or its management. However, a common problem is that these more complex dimensions go unacknowledged and unaddressed. The seemingly intractable nature of such situations, combined with a limited understanding of the deeper-seated issues that cause them, often causes practitioners to favour short term technical or legislative approaches to conflict management that focus primarily on alleviating the negative impacts of species on humans, or vice versa. Yet a growing body of literature suggests that failure to recognise and confront these underlying socio-political elements only causes conflicts to persist and worsen. In Scotland, a current long-standing conflict exists around the interests of raptor conservation and driven grouse shooting. The situation is highly contentious; actors have become polarised and arguments over key issues, such as the illegal killing of raptor species, are embedded within wider socio-political issues that consider land ownership, governance, and positions of authority. Despite multiple technical and legislative measures, evidence suggests the illegal killing of raptors is ongoing and the fractured relationships among stakeholders have stalled efforts at negotiation and collaboration. However, little scholarly work has studied these relationships and the issues that shape them. This thesis aims to contribute to the understanding of stakeholder interactions, and the deeper-rooted social and political elements that influence how stakeholders perceive the situation and one another. To do so, I take a social science perspective, drawing on theoretical frames and methodologies from several disciplines to provide an in-depth examination of aspects of a conservation conflict that, up until now, have received relatively little attention. In a more global context, this thesis contributes to the burgeoning literature relating to the social and political dimensions of conservation conflicts. Although the scope of research into the human dimensions of conservation has expanded substantially in the last decade, there remains significant gaps in our knowledge of such situations. One such gap relates to the perspectives of conservationists, or species 'advocates'. Previous research has largely focussed on the views of stakeholders who are seemingly opposed to the objectives of conservation. However if conservation conflicts are to be understood as inherently socio-political issues among people - with strongly-held, often divergent views and values - then we cannot ignore conservation advocates as influential actors, with integral roles within the conflict that must also be understood. The research presented therefore investigates a diverse array of perspectives, ranging from those of actors with predominantly conservation interests, to those more orientated towards field sports and rural land use. The second concerns the exploration of the different levels of actors involved in conservation conflicts; the differences and interactions within and between the institutional, national level and regional, local stakeholders. This thesis therefore focuses on the inter- and intra-group dynamics among these levels, and is split into two parts. Chapters 2 & 3 investigate the conflict at a national level, using discourse analysis to examine the interactions between non-governmental organisations and state bodies. A critical finding is that institutional level actors contest discursively, communicating often divergent interpretations of key issues and scientific research to advance their own position. Chapters 4 & 5 then explore the relationships and narratives of local-level stakeholders through semi-structured interviews, and explore the connections between this and the institutional level. Analysis revealed themes of power, representation, and trust that influenced inter- and intra-group dynamics. An important finding was that local stakeholders often felt powerless and under-represented in decision making processes, suggesting that institutionalised discourses - which did not necessarily reflect local perspectives - were dominating discussions surrounding conflict management and preventing constructive dialogue. Chapters 5 & 6 discuss the implications of our findings for conflict management and use this understanding to make suggestions of strategies that are of higher relevance to the important socio-political dimensions of conflicts, and are better aligned with the perspectives and needs of local stakeholders. Overall, this thesis demonstrates that a major barrier to the management of raptor-grouse conflict concerns the relationships of the actors involved - particularly those between actors at the national and local levels. I therefore suggest that multiple management interventions at different levels are required as part of a longer-term, evolutionary process, aiming to develop a better environment in which to hold discussions about not just raptors, but wider issues of land ownership and governance in Scotland. These findings are then placed in a more global context, with suggestions made as to how a broader perspective orientated towards the relationships among actors may be translated to different conservation conflicts in other parts of the world.

Protected areas under pressure: decline, redistribution, local eradication and projected extinction of a threatened predator in Doñana National Park

Article

Full-text available

Apr 2019

After a period of overfocus on the establishment of reserves, attention is increasingly being devoted to the capability of protected areas to maintain viable populations of endangered species. Here, we examined the trends and reproduction of the red kite Milvus milvus, a highly endangered raptor near-endemic to Europe, to illustrate the dual benefits and challenges faced by a national park to protect this iconic species. Over the past 4 decades, the kite population of southern Spain has declined steeply and has become progressively confined to Doñana National Park and its buffering Natural Park areas. Population deterioration was also evident within the protected area through (1) spikes of rapid eradication of whole sub-populations from buffer areas, likely propelled by illegal poisoning, and (2) more gradual but steady deterioration of numbers and reproduction, especially in peripheral buffer areas, probably caused by the interplay of several shocks related to food availability, habitat degradation, competition, predation, and chemical contamination. The result was a 46-55% decline with progressive confinement to the core National Park and an alarming effective population size of

Direct evidence of poison-driven widespread population decline in a wild vertebrate

Article

Jun 2020

Toxicants such as organochlorine insecticides, lead ammunition, and veterinary drugs have caused severe wildlife poisoning, pushing the populations of several apex species to the edge of extinction. These prime cases epitomize the serious threat that wildlife poisoning poses to biodiversity. Much of the evidence on population effects of wildlife poisoning rests on assessments conducted at an individual level, from which population-level effects are inferred. Contrastingly, we demonstrate a straightforward relationship between poison-induced individual mortality and population changes in the threatened red kite ( Milvus milvus ). By linking field data of 1,075 poisoned red kites to changes in occupancy and abundance across 274 sites (10 × 10-km squares) over a 20-y time frame, we show a clear relationship between red kite poisoning and the decline of its breeding population in Spain, including local extinctions. Our results further support the species listing as endangered, after a breeding population decline of 31% to 43% in two decades of this once-abundant raptor. Given that poisoning threatens the global populations of more than 2,600 animal species worldwide, a greater understanding of its population-level effects may aid biodiversity conservation through increased regulatory control of chemical substances. Our results illustrate the great potential of long-term and large-scale on-ground monitoring to assist in this task.

Demographic modeling to fine‐tune conservation targets: importance of pre‐adults for the decline of an endangered raptor

Article

Nov 2020

Large, long‐lived species with slow life histories and protracted pre‐breeding stages are particularly susceptible to declines and extinction, often for unknown causes. Here, we show how demographic modelling of a medium‐sized raptor, the Red kite Milvus milvus, can aid to re‐focus conservation research and attention on the most likely mechanisms driving its decline. Red kites’ survival and reproduction increased through three sequential stages for 1‐2, 3‐6 and 7‐29 years of age, mainly corresponding to individuals that are dispersing, attempting to gain a territory, and breeding. As typical of long‐lived species, elasticities were highest for adult (≥ 7 years old) survival, but this was high, with little scope for improvement. Instead, the declines were driven by an extremely low survival of pre‐adults in their first years of age, which weakened the whole demographic system by nullifying the offspring contribution of adults and curtailing their replacement by recruits. For example, 27 pairs were necessary to generate a single prime age adult. Simulation of management scenarios suggested that the decline could be halted most parsimoniously by increasing pre‐adult survival to the mean levels recorded for other areas, while only the synergistic, simultaneous improvement of breeding success, adult and pre‐adult survival could generate a recovery. We propose three actions to attain such goals through selective supplementary feeding of both breeding and non‐breeding individuals, and through mortality‐improvement by GPS remote‐sensing devices employed as surveillance monitoring tools. Our results show how improving demographic models by using real, local vital rates rather than “best guessed” ones can dramatically improve model realism by refocusing attention on the actual stages and mortality causes in need of manipulation, thus building precious time and resources for conservation management. These results also highlight the frequent key role of pre‐adult survival for the management of long‐lived species, coherent with the idea of demographic systems as integrated chains only as strong as their weakest link.

Abhängigkeit des Erstbrutalters von der Populationsdichte: Eine Integration in Populationsmodelle für den Rotmilan Milvus milvus

Article

Oct 2019

Integrating density-dependent age of first breeding into population models for the Red Kite Milvus milvus. Vogelwelt 139: 171-180. ---------- READ FULL TEXT HERE https://www.dda-web.de/downloads/publications/vogelwelt/139/katzenberger_gottschalk_erstbrutalter_populationmodell.pdf ---------- Population viability analysis using matrix models is by now a standard method in both scientific and applied nature conservation. The main input parameters for such models are the survival rates of different age groups, reproduction and potentially emigration/immigration. Apart from these, the proportion of breeding birds in different age classes is an important parameter, especially for territorially breeding raptors. A dependence of the age of first breeding on the density (size of the total population in relation to carrying capacity) can be of major importance for population development but is so far mostly overlooked in population modelling. We derive a simple, density-dependent formula for the age of first breeding, based on two Red Kite case studies, and show how this formula can be integrated into population models using the VORTEX software. Based on demographic data, we reconstruct a Red Kite model population in Germany from 1975-2015 and compare its population development with index values from breeding bird surveys on sample plots from 1988-2014. The results show that a model structure with density dependence in the age of first breeding fits better to the available data than commonly assumed fixed proportions in different age classes. Under lower densities, an increased proportion of birds breeding at the age of two and three years allows a long-term stabilisation of population development. This process however leads to a continuous decline of the non-breeding part of the population, which usually acts as a reserve that to a certain degree buffers further deterioration in reproduction or mortality. From a conservation point of view, this situation poses a considerable threat to the continued existence of the population, despite a short-term stabilisation of the population development. Our analysis shows that the consideration of the non-breeding part of the population and the age of first breeding plays an important role for a better understanding of the population dynamics of the German Red Kite population. To make robust projections of population development, the interplay between age of first breeding, density, mortality, reproduction and, where appropriate, emigration/immigration must be better understood and parameterised in population models.

Density‐dependent age of first reproduction as a key factor for population dynamics: stable breeding populations mask strong floater declines in a long‐lived raptor

Article

Full-text available

Apr 2021

The age at which individuals reproduce for the first time is a key demographic factor impacting population dynamics and is subject to substantial variation across animal populations. There is also widespread empirical evidence that age of first reproduction responds to changes in population density over time, especially for long‐lived birds and mammals. The density dependence in age of first reproduction has profound impacts on the size of the non‐breeding (‘floater’) part of the population. A better understanding of floater dynamics in raptor populations is urgently needed for comprehensive assessments of conservation status and management. We use the European near‐endemic red kite Milvus milvus, a long‐lived raptor of conservation concern, as an example to investigate total population dynamics with an age‐structured demographic model. Using published estimates of survival and reproduction, we model the red kite population in Germany over four decades, considering also density dependence in the age of first reproduction in different model scenarios. Based on the literature and the results of our simulations, we show that age of first reproduction for the red kite most likely responds non‐linearly to density and that this general feedback mechanism should regularly be considered in demographic simulations. Our model results have far‐reaching implications for the conservation status of the red kite, as they highlight a drastic decrease of juvenile and non‐breeding individuals in the population over time – driven both by declining vital rates and a density‐dependent shift towards a younger age of first breeding. This process is not visible when judged only by the size of the breeding population, which our model estimates to be of similar size today as in the 1980s. The total red kite population reconstructed for Germany, however, seems diminished to nearly 50% of its former size.

Habitat use and population viability of the Red Kite (Milvus milvus) in Germany

Thesis

Full-text available

May 2021

Jakob Katzenberger

Full-Text: http://hdl.handle.net/21.11130/00-1735-0000-0008-5814-F The Red Kite (Milvus milvus) is a European near-endemic raptor species and due to its limited distribution and small global population size in the focus of national and international conservation efforts. Even within Europe, the distribution of the Red Kite is strongly restricted and the majority of the species’ breeding and wintering populations, especially in Germany and Spain, showed declines over the last decades. In contrast, some reintroduced or formerly marginal Red Kite populations, especially in in the UK, Switzerland and Sweden, showed increasing populations in recent years. Red Kites are opportunistic scavengers in the agricultural landscape and the species has seen a changeful history of population increase and decline, strongly linked to human cultivation of farmlands and anthropogenic mortality. In comparison to other raptors and considering its intermediate size, the Red Kite is an extremely long-lived and highly social bird species – which strongly affects its demography and distribution. Although mortality of adult breeding individuals has by far the strongest impact on Red Kite population growth rates, demographic data and studies on age-specific survival rates are lacking – limiting the understanding of the species’ population trends. Also, the impact of apparent strong philopatry on breeding occurrence and population development of Red Kites as well as the consequences of a propensity for delayed recruitment (‘floating’ behaviour) are currently not well understood. The aim of this doctoral thesis is to synthesise data on Red Kite demography and distribution from Germany with current analytical methods, to increase the understanding of central demographic rates and to describe crucial influencing variables for the species’ breeding occurrence. The results are expected to inform conservation and research on the Red Kite in Germany and to contribute to a scientific basis for evidence-based management in the future. Chapter 2 addresses the lack of recent age-structured survival estimates for the Red Kite in Germany. Using a long-term dataset of nearly 30,000 Red Kites marked with metal rings and about 1500 dead recoveries of these individuals, we estimate age-specific survival probability over nearly 50 years in a major part of the German Red Kite population. With a multinomial ring-recovery model, we consider age-dependent recovery probability, based on separate datasets of birds marked as nestlings and as adults/immatures, and thereby estimate juvenile, subadult and adult survival probability over time. The results showed a substantial long-term decline in Red Kite juvenile survival of more than 40 % from the 1970s until today. Furthermore, from years 1974-2014 adult survival probability showed a consistently decreasing trend (-0.26 % p.a.). The recovery probability for dead Red Kites in the first year (as juveniles) was estimated as being two times lower than for birds that reach subadult/adult age classes, which could be related to differing causes or locations of death in the first year of life. The spatiotemporal patterns in juvenile Red Kite recoveries suggested an increase in mortality at the breeding grounds, but in >60 % of the cases the cause of death was unknown or not reported. To understand which factors are driving changes in survival of the Red Kite, age-dependent causes of mortality need further study. This work lays the foundation for further analyses of Red Kite population viability in this thesis and it allows to study annual variation in Red Kite survival and its potential drivers in the future. Chapter 3 examines how environmental factors and local correlation patterns shape the breeding distribution of the Red Kite in Germany. Based on a national-scale population survey, with more than 6,000 breeding occurrences and high-resolution data on land use, habitat structure and climate variables, it decomposes environmental variability and spatial correlation and derives predictions of habitat suitability and probability of occurrence for the Red Kite in Germany. To account for spatial autocorrelation in the distribution data, a hierarchical model was used which corrects the model estimates using random effects (‘Gaussian random fields’). The model results showed very good predictive accuracy (AUC = 0.89) and explained 64.6 % of the variability in the distribution data, of which more than half was attributable to the environmental variables. Local occurrence of the Red Kite was strongly influenced by agricultural use and habitat diversity, but also by human disturbance. A high proportion of grassland in the surroundings, but also arable fields paired with woody margins (groves, hedges etc.) strongly increased the probability of a Red Kite nest being present. In addition, the results showed a substantial negative effect of agricultural intensification on the occurrence of the Red Kite, measured by the density of livestock farming. Model predictions of habitat suitability confirmed the need of a spatially comprehensive approach for protection in Germany, while the actual distribution of the Red Kite in some areas also deviated substantially from the model predictions. The work underlines and extends previous evidence on important habitat characteristics for the Red Kite, which is necessary for well-targeted habitat improvements, but also opens new possibilities to identify essential habitats for effective spatial protection measures. Chapter 4 investigates the total population dynamics of the Red Kite in Germany using an age-structured demographic model. Based on the survival estimates from chapter 2 and published data on reproduction, we reconstructed key features of the population development over nearly 40 years in different age classes, including also non-breeding (‘floater’) individuals. Because recruitment age is a key demographic factor and varies substantially across Red Kite populations, we also considered a simple density-dependent function for age of first reproduction based on the literature in different model scenarios. The simulations showed a drastic decrease of juvenile and non-breeding individuals in the Red Kite population over time – driven both by declining vital rates and a density-dependent shift towards a younger age of first breeding. This process was however not visible when judged by the size of the breeding population, which our model estimated to be of similar size today as in the 1980s. The total Red Kite population, including also non-breeding and juvenile individuals, was reduced to nearly 50 % of its former size in our reconstruction. Comparing the different model scenarios with existing estimates of breeding population size in Germany suggested that age of first reproduction for the Red Kite most likely varies non-linearly with density. Such a general feedback mechanism has largely been overlooked in previous studies but should be considered for improving the robustness of demographic simulations. The model reconstruction also highlights that conservation assessments for long-lived bird species, with a propensity for floating behaviour, profit from further demographic data and modelling procedures to avoid overlooking potentially cryptic population declines.

Population Change of Red Kites Milvus milvus in Central Southern England between 2011 and 2016 Derived from Line Transect Surveys and Multiple Covariate Distance Sampling

Article

Full-text available

Feb 2020

Successful reintroduction programmes are usually defined by an increase in size and extent of the new population after a given period of time. Among studies of birds, these population estimates are often focused on the monitoring of nesting attempts and productivity. For many raptors, however, this approach can overlook a large number of non-breeding adults and immature birds leading to underestimation of population size and reproductive potential. A more thorough approach is to generate assessments of total population size. In this study we used a line transect survey methodology and multiple covariate distance sampling to assess the change in population size of a reintroduced raptor species, Red Kite Milvus milvus, across a 2600 km2 area of central southern England. Surveys were performed in spring and autumn between 2011 and 2016 in an area 45 km to the south of the initial English reintroduction project which started 25 years previously. Survey routes avoided using roads where possible to counter the potential attraction that such landscape features may have (e.g. increased food availability, perches etc.). The use of roads was unavoidable in some instances; however, we found no evidence of Red Kite attraction to these landscape features when comparing distances of observations from stretches along roads with 5000 randomly-generated locations. Distance of detection was influenced by bird activity (greatest when the bird was on the ground or interacting with other birds) and extent of woodland but not by time of day, seasonality or when comparing between years. During the five years, estimated population size doubled from approximately 490 to 1100 individuals; a density of one Red Kite per 2.5–3.5 km2. This suggests an increase in the breeding population in the study area from c. 95 to 174 pairs. During the study, rate of population growth was not uniform; rapid growth was recorded in years two and three followed by a slowing over the last two years of the study. While an overall increase in population and availability of suitable nesting habitat across south-eastern England indicates that there is still potential for expansion of the Red Kite breeding population, other factors are potentially limiting this growth.

Killing of raptors on grouse moors: evidence and effects

Article

Full-text available

Oct 2020

Ian Newton

Owing to the intensity of game management in Britain, managers of grouse moors have illegally killed raptors to increase the numbers of Red Grouse Lagopus l. scotica available for shooting. This paper summarizes evidence for the recent scale of illegal raptor killing on grouse moors and its effects on populations. It provides insights into how raptors themselves respond demographically to different levels of killing. Over Britain as a whole, most raptors have increased and expanded considerably since the 1970s, in response to reduced killing and nest destruction, and the diminished impacts of organo‐chlorine pesticides; however, in recent decades the populations of some species have declined on and around grouse moors. This is widely evident in Hen Harrier Circus cyaneus, Peregrine Falcon Falco peregrinus and Golden Eagle Aquila chrysaetos populations and in more restricted areas also in Northern Goshawk Accipiter gentilis and Red Kite Milvus milvus populations, in all of which illegal killing has been sufficient to affect numbers over wider areas. The evidence consists mainly of: (1) greater disappearance of nesting pairs, lower breeding densities or reduced occupancy of apparently suitable traditional territories on grouse moors compared with other areas; (2) reduced nest success compared with other areas; (3) reduced adult survival compared with other areas; (4) reduced age of first breeding, reflecting the removal of adults from nesting territories and their replacement by birds in immature plumage; (5) greater levels of disappearance of satellite‐tracked birds on grouse moors than elsewhere; and (6) the finding of poisoned baits and traps, and shot or poisoned carcasses of raptors. Not all these types of evidence are available for every species, and other types of evidence are available for some. The Common Buzzard Buteo buteo is currently the most numerous raptor in Britain and also seems to be killed in the greatest numbers. Other raptor species, including Merlin Falco columbarius, Common Kestrel Falco tinnunculus and Eurasian Sparrowhawk Accipiter nisus which nest on or near grouse moors, have little or no significant impact on grouse and are killed less often or not at all. In the absence of illegal killing, some raptor species breed as well or better on grouse moors than in other habitats. Merlins, in particular, seem to thrive on grouse moors, benefiting from the management involved (including predator control). Other aspects of illegal raptor killing are discussed, including suggestions for ways in which it might be reduced.

Raptor research during the COVID-19 pandemic provides invaluable opportunities for conservation biology

Article

Full-text available

Apr 2021
BIOL CONSERV

Research is underway around the world to examine how a wide range of animal species have responded to reduced levels of human activity during the COVID-19 pandemic. In this perspective article, we argue that raptors are particularly well-suited for investigating potential ‘anthropause’ effects, and that the resulting insights will provide much-needed impetus for global conservation efforts. Lockdowns likely alter many of the extrinsic factors that normally limit raptor populations. These environmental changes are in turn expected to influence – mediated by behavioral and physiological responses – the intrinsic (demographic) factors that ultimately determine raptor population levels and distributions. Using this framework, we identify a range of research opportunities and conservation challenges that have arisen during the pandemic. The COVID-19 anthropause allows raptor researchers to address fundamental and applied research objectives in a large-scale, quasi-experimental, well-replicated manner. Importantly, it will be possible to separate the effects of human disturbance and anthropogenic landscape modifications. We explain how high-quality datasets, accumulated for a diverse range of raptor species before, during, and after COVID-19 lockdowns, can be leveraged for powerful comparative analyses that attempt to identify drivers of particular response types. To facilitate and coordinate global collaboration, we are hereby launching the ‘Global Anthropause Raptor Research Network’ (GARRN). We invite the international raptor research community to join this inclusive and diverse group, to tackle ambitious analyses across geographic regions, ecosystems, species, and gradients of lockdown perturbation. Under the most tragic of circumstances, the COVID-19 anthropause has afforded an invaluable opportunity to significantly boost global raptor conservation.

Endangered bird mortality by gunshots: still a current problem

Article

Full-text available

Aug 2019
BIODIVERS CONSERV

Alfonso Balmori

This study analysed the illegal shootings of threatened species through information compiled from rehabilitation centres in Spain. Our objective was to assess whether this cause of mortality has reduced or increased over time and to verify if gunshots could be causing a decline of especially vulnerable species. We also aimed to identify the monthly distribution of gunshots, and whether they corresponded to hunting periods. A total of 67 not hunting species were shot, 58 species classified as “Least Concern”, six species as “Near Threatened”, two species as “Vulnerable” and one specie as “Endangered” according the IUCN red List. Across the whole set of species, as well as among “Least Concern”, there has been a decrease in the number of specimens shot over the years. However, for species “Near Threatened”, “Vulnerable” and “Endangered”, a maintained trend over time was observed. More gunshots on threatened species occurred during hunting periods, but gunshots occurred during all months of the year. One of the periods with more gunshots, in August and September, is caused by the shooting of trans-Saharan migratory species, such as the Montagu’s Harrier, the Hobby, the Booted Eagle and the Black Kite. Another peak in gunshots occurs between October and January, and particularly affects sedentary and wintering species. The most frequently shot species have shown decreasing population trends, although there is fragmentary information to obtain accurate data. Gunshots remain a serious problem for threatened species in relation to its population and it is important to reduce this cause of no natural mortality.

Recent Avian Poisonings Suggest a Secondary Poisoning Crisis of Black Kites During the 1980s in Taiwan

Article

Sep 2018
J RAPTOR RES

The Black Kite (Milvus migrans) has a limited distribution within Taiwan due to a dramatic population decrease during the late 20th century. Prompted by some poisoning incidents of Black Kites and other farmland birds, we hypothesized that poisoning may be an underreported yet important threat. Thus, we created a citizen-science Facebook group in October 2014 in order to receive more information about possible poisoning incidents. By September 2016, we had received reports of 4753 dead birds in 213 separate poisoning incidents in agricultural areas. The types of fields most often associated with poisoning incidents were direct-seeded rice (Oryza sativa), rice that was soon to be harvested, and red beans (Vigna angularis). We tested tissues from 29 dead small birds for pesticide residues. Twenty-eight birds contained carbofuran, and one bird contained terbufos, both highly toxic pesticides. Furthermore, of seven dead Black Kites tested from 2010 to 2016, four contained carbofuran, and three contained second-generation anticoagulant rodenticides. After interviewing farmers and reviewing older agricultural literature, we concluded that most of these incidents represented intentional poisonings by farmers attempting to control avian pests and rats (mostly Bandicota indica and Rattus spp.). We suggest that the Black Kites were likely the victims of inadvertent secondary poisoning incidents. The dramatic decrease of the Black Kite in the 1980s coincided with the rapid increase in the area planted with direct-seeded rice and the widespread use of carbofuran and rodenticides. The recent decreased use of these pesticides due to restrictions has coincided with the recent slow recovery of the Black Kite population. Therefore we initiated public awareness campaigns, and the Taiwanese government has adjusted some pesticide-use policies.

Age, landscape, and arrival date explain ranging behavior of wintering red kites in southwest Europe

Article

Dec 2021

Understanding intrinsic and extrinsic influences of movement behavior in migratory species, with the potential to recommend management actions for species of conservation concern, requires data from across the species' range. For some raptor species, such as the red kite (Milvus milvus; kite), existing data focus on breeding populations or movements en route to wintering areas without considering movements within the wintering areas. Here, we contribute to filling this knowledge gap by investigating landscape‐level associations of kites in their southwestern European winter ranges between 2015 and 2020. We also explore aspects of the migration process in terms of geographical patterns in the location of over‐wintering grounds, including time spent and distances traveled within them. We predicted that space use in over‐wintering areas would be linked to the proportional amount of open, lowland, or urban land cover they contain at the land-scape level. Specifically, we tested whether winter range sizes (95% kernel density estimator [KDE] home ranges and 50% KDE core areas) would be smaller in areas with greater proportional open and urban land cover within kite ranges. Controlling for the effects of age and sex, we compared results in 3 over‐wintering regions: the Iberian Peninsula, Italy, and the Pyrenean region of southern France. We tracked 36 kites by global positioning system‐global system for mobile communications (GPS‐GSM) telemetry over 70 individual winters between 2015 and 2020. Kites wintering in the Pyrenees had larger home ranges and core areas but moved less than those wintering in Italy and the Iberian Peninsula. As predicted, ranges were smaller in areas with greater proportional open and lowland land cover; however, there was no effect of urban areas. Older kites that arrived late to the wintering areas had larger home ranges than those that arrived early or on time. During the study 20 kites died or the transmitter malfunctioned. Six of 13 confirmed deaths were due to anthropogenic activity; 5 kites were poisoned. Our results confirm that land use and elevation are key influences of kite space use in southwestern European over‐wintering populations, but additional demographic intrinsic factors also affect ranging parameters. These data indicate that over‐winter conservation action for kites, for example supplementary feeding with livestock carrion, should focus on open lowland landscapes throughout the species' winter range.

Fighting talk: Organisational discourses of the conflict over raptors and grouse moor management in Scotland

Article

Sep 2018
LAND USE POLICY

The Scottish Raptor Monitoring Scheme: recent developments in good practice monitoring

Article

Full-text available

Jan 2019
BIRD STUDY

Capsule: The Scottish Raptor Monitoring Scheme (SRMS) has been operational for 15 years and provides many examples of how nationwide monitoring programmes for raptors and other scarce bird species could be developed. Aims: To share experiences and approaches to the coordination of a nationwide raptor monitoring programme that other countries can use when embarking on their own monitoring programme for raptors or other scarce species. Methods: We present seven current developments to enhance the SRMS, including: (i) profile raising, (ii) producing robust population trends, (iii) increasing monitoring of widespread species, (iv) expanding the volunteer network, (v) enhancing reporting on causes of breeding failure, (vi) developing an online data entry system and (vii) mobilizing data for conservation purposes. Results: We present the first results on survey coverage and trends of raptor species in Scotland and highlight some of the challenges, including production of trends, data mobilization and lack of diverse income streams. Conclusion: We recommend that new raptor monitoring programme should at the outset ensure that the aims of the monitoring programme are clearly defined and that agreement is reached regarding how data will be stored and shared. Consideration should be given to the potential uses of the data and the intended outputs from the programme, and the suitability of scheme design to meet the agreed objectives. A recording system that captures all required aspects of the data recording should be devised and implemented at an early stage.

Totfundstatistik und Verlustursachen beim Rotmilan Milvus milvus in Sachsen-Anhalt

Article

Full-text available

Sep 2019

Der Rotmilan Milvus milvus hat ein kleines, auf Europa beschränktes, Verbreitungsgebiet in dem mehr als die Hälfte der Weltpopulation auf dem Gebiet von Deutschland brütet. Demnach gilt diese Vogelart als Verantwortungsart für Deutschland und ist nach Anhang 1 der EU-Vogelschutzrichtlinie geschützt. Zudem wird dem Rotmilan wegen seiner uneinheitlichen Bestandsentwicklung mit Abnahmen in Mittel- und Ostdeutschland und Zunahmen in Süddeutschland seit einigen Jahren eine besondere Aufmerksamkeit geschenkt. Zugleich gilt er als die „Problemart“ beim Ausbau der Windenergie schlechthin. In diesem Kontext wird die Art in den meisten Fällen von ihren Habitat- und Raumansprüchen her betrachtet. Bei der Vielzahl an Untersuchungen in den letzten Jahren bleibt ein wesentlicher und für die Bestandsentwicklungen entscheidender Faktor unberücksichtigt: die allgemeine Sterblichkeit und die Verlustursachen. Aus dem Zeitraum von 1951 bis 2019 wurden 658 Meldungen von toten Rotmilanen in Sachsen-Anhalt aus verschiedenen Quellen zusammengetragen und ausgewertet. Von ca. 41 % der Funde lagen keine genauen Angaben zur Todesursache vor. Im Zeitraum von 1951 bis 1999 dominierten unter Berücksichtigung aller Altersklassen die Verluste an elektrischen Freileitungen (28,7 %) und menschlicher Verfolgung (27,0 %). Unter den Funden aus den Jahren von 2000 bis 2019 überwiegen die Opfer von Kollisionen an Windenergieanlagen (45,6 %), während Verfolgung durch Menschen (1,5 %) und der Tod an elektrischen Freileitungen (4,9 %) in Sachsen-Anhalt heute kaum noch eine große Rolle spielen. Eine weitere wichtige Todesursache in den letzten 20 Jahren ist die Kollision mit Straßenfahrzeugen (13,2 %), welche seit den 1960er Jahren kontinuierlich zunimmt. Bei Vögeln, die zwischen 2000 und 2019 innerhalb des ersten Kalenderjahres starben, sind die häufigsten Todesursachen Prädation (52,9 %) und Kollision mit Straßenfahrzeugen (23,5 %). Bei Vögeln, die im gleichen Zeitraum im 2. Kalenderjahr oder später starben, sind die häufigste Ursache Kollisionen an Windenergieanlagen (36,5 %) und Kollision mit Straßenfahrzeugen (16,8 %).

Biologische Maßstäbe für das artenschutzrechtliche Tötungsverbot. Stand und Anwendungsmöglichkeiten

Article

Full-text available

Jan 2020

Jochen Bellebaum

Im deutschen Recht hat sich der Maßstab der signifikanten Erhöhung des Tötungsrisikos im Vergleich zum allgemeinen Lebensrisiko als Kriterium für die Unzulässigkeit von Vorhaben etabliert, es fehlt aber an Richtlinien für die Beurteilung des Signifikanzkriteriums aus § 44 Abs. 5 BNatSchG. Hier wird eine Möglichkeit zur objektiven Beurteilung anhand bewährter wissenschaftlicher Methoden vorgeschlagen, die grundsätzlich auf alle Wirbeltiere anwendbar ist. Eine objektive Bestimmung des allgemeinen Lebensrisikos ist möglich durch umfangreiche Erkenntnisse zu Überlebenswahrscheinlichkeiten besonders bei Vögeln und Fledermäusen. Die Prognose vorhabenbedingter Tötungsrisiken beruht derzeit vor allem auf Untersuchungen an verwirklichten Vorhaben, die durch Monitoringauflagen bei Genehmigungen ergänzt werden können. Zusätzlich zum individuenbezogenen Risiko muss unter Umständen auch die additive Wirkung von Mortalität auf Populationsebene mit dem „ORNIS-Kriterium“ beurteilt werden, um eine Verschlechterung des Erhaltungszustandes auszuschließen. Bei Überschreitung der Referenzwerte bzw. Signifikanzschwellen kann eine Ausnahmeprüfung nach § 45 Abs. 7 BNatSchG folgen. Fallbeispiele zeigen, wie eine objektive Beurteilung des Tötungsrisikos für bekannte Risiken durch Windenergieanlagen bereits möglich ist.

GPS-basierte Telemetriestudien an mitteleuropäischen Rotmilanen Milvus milvus – methodische Schwierigkeiten und analytische Möglichkeiten basierend auf ersten Ergebnissen

Article

Full-text available

Aug 2017

GPS-based telemetry studies of Central European Red Kites Milvus milvus – methodical difficulties and analytical opportunities based on the initial results Although satellite telemetry increasingly gains in importance in research on birds of prey, there are relatively few telemetry studies on Red Kites Milvus milvus dealing with behavioural aspects during breeding, migration or at overwintering sites. Based on telemetry data we can deepen our knowledge on the ecology of this species and consequently adapt and improve conservation measures for this endangered species, which is listed as NT (near threatened) on the IUCN Red List of Threatened Species. Therefore, since 2014, Red Kites have being tagged in Austria, the Czech Republic and Slovakia. By using the GPS-GSM-UHF-technology, data can be transferred either via radio data transmission to a handheld device or via the GSM-network, making data available through an online web application. GPS-locations received in this way are not only of high spatial accuracy, but also contain information on a bird’s flight altitude and flight speed. Compared to battery-powered loggers, solar-powered loggers enable high temporal data transmission over several years. On the other hand, bad light conditions can cause battery problems for solar-powered loggers, which in turn can lead to a low frequency of, or even a complete failure in data transmission. To obtain data in high temporal and spatial resolution over long periods, the use of the UHF-system and associated temporal and financial extra-effort are inevitable, as the high battery drain in this case does not permit the use of the GSM-system. Between 16.07.2015 and 15.07.2016, preliminary results of 15 out of 19 Red Kites tagged in the year 2015 show differences in the migration behaviour between individuals, and underline the importance of Italy and the Balkan Peninsula as vital overwintering sites for Central European Red Kites. The crossing of geographical barriers by this thermal soarer was unexpected, but GPS locations documented six seacrossings by four individuals. Five of these 15 Red Kites died prior to 15.07.2016, with four of them being illegally poisoned. These preliminary results already give some new insights into the use of overwintering sites and the migration behaviour of Central European Red Kites. Additionally, spatial and temporal high-resolution telemetry data enhance the probability of finding Red Kite carcasses, making a reliable investigation of cause of death possible. Based on these results, key mortality factors can be identified. Hence, telemetry studies act as an important tool in the protection of birds of prey in general and in the protection of the Red Kite in particular. Preliminary results presented in this study will be processed and published in detail at a future date. Literatur Bellebaum, J.; Korner-Nievergelt, F.; Dürr, T.; Mammen, U. (2013): Wind turbine fatalities approach a level of concern in a raptor population. - Journal of Nature Conservation 21: 394-400. BirdLife International (2017): Milvus milvus. The IUCN Red List of Threatened Species 2017: e. T22695072A110921280. http://www.iucnredlist.org/ details/summary/22695072/0. Zugriff am 26.05.2017. Cagnacci, F.; Boitani, L.; Powell, R. A.; Boyce, M. S. (2010): Animal ecology meets GPS-based radiotelemetry: a perfect storm of opportunities and challenges. - Philosophical Transactions of the Royal Society B 365: 2157-2162. Cooke, S. J. (2008): Biotelemetry and biologging in endangered species research and animal conservation: relevance to

The Red Kite Reintroduction: thirty years on

Article

Full-text available

Aug 2019

Ian Carter

Quantification of anthropogenic food subsidies to an avian facultative scavenger in urban and rural habitats

Article

Jul 2019
LANDSCAPE URBAN PLAN

The provision of anthropogenic food to wildlife is a global phenomenon, and intentional wild bird feeding has become increasingly popular in the last decades. Though there is anecdotal evidence of feeding of avian fa-cultative scavengers in rural areas, most studies of wild bird feeding in Europe and the United States focused on passerines and urban contexts. We aim at quantifying the extent of feeding by private residents to an avian facultative scavenger, the red kite (Milvus milvus), in Swiss urban and rural areas by conducting a face-to-face systematic survey (N = 199 randomly selected houses) in a 275 km 2 study area. 4.6% of urban and 12.7% of rural households regularly fed red kites. While building density negatively affected the probability of households providing food, daily anthropogenic food mass was larger in urban than in rural areas, mainly due to the higher number of households. Daily availability was also larger in winter than in the rest of the year. In total, 47-86 metric tons of anthropogenic food was provided yearly, which represents a maximum daily average of nearly 0.9 kg of food per km 2. We conclude that intentional (20%) and unintentional (80%) provision of anthropogenic food to facultative scavengers are widespread and well-established human behaviors in Switzerland. These behaviors provide high food availability over the year in both rural and urban areas. The results represent an important basis for understanding the ecological consequences of anthropogenic food provisioning, human-scavenger interactions, and scavenger population dynamics in anthropogenic landscapes.

Diversionary feeding as a means of reducing raptor predation at seabird breeding colonies

Article

Sep 2018
J NAT CONSERV

Occurrence of Red Kites Milvus milvus in Serbia based on birds tracked by telemetry devices

Article

Full-text available

Nov 2018

A total of 13 Red Kites Milvus milvus fitted with GPS/GSM telemetry loggers in central Europe were tracked in Serbia from 10 July 2014 until 31 March 2018. These birds remained in Serbia for 138 days (counted as number of one bird/one day stays). Red Kites occurred mostly in the Vojvodina Province (NW Serbia). They were registered most often in April and October, which corresponded to their spring and autumn migrations. It is possible that Red Kites occur in Serbia more often than formerly, and this could in future result in this threatened European raptor’s more frequently wintering and breeding within the country.

Assessing population size and structure for Andean Condor Vultur gryphus in Bolivia using a photographic ‘capture-recapture’ method

Article

Full-text available

Oct 2018

The Andean Condor Vultur gryphus is a globally threatened and declining species. Problems of surveying Andean Condor populations using traditional survey methods are particularly acute in Bolivia, largely because only few roosts are known there. However, similar to other vulture species, Andean Condors aggregate at animal carcasses, and are individually recognisable due to unique morphological characteristics (size and shape of male crests and pattern of wing coloration). This provided us with an opportunity to use a capture‐recapture (‘sighting‐resighting’) modelling framework to estimate the size and structure of an Andean Condor population in Bolivia using photographs of individuals taken at observer‐established feeding stations. Between July and December 2014, twenty‐eight feeding stations were established in five different zones throughout the eastern Andean region of Bolivia, where perched and flying Andean Condors were photographed. Between 1 and 57 (mean = 20.2 ± 14.6 SD) Andean Condors were recorded visiting each feeding station and we were able to identify 456 different individuals, comprising 134 adult males, 40 sub‐adult males, 79 juvenile males, 80 adult females, 30 sub‐adult females and 93 juvenile females. Open population capture‐recapture models produced population estimates ranging from 52 ± 14 (SE) individuals to 678 ± 269 individuals across the five zones, giving a summed total of 1388 ± 413 individuals, which is roughly 20% of the estimated Andean Condor global population. Future trials of this method need to explicitly consider knowledge of Andean Condor movements and home ranges, habitat preferences when selecting suitable sites as feeding stations, juvenile movements and other behaviours. Sighting‐resighting methods have considerable potential to increase accuracy of surveys of Andean Condors and other bird species with unique individual morphological characteristics. This article is protected by copyright. All rights reserved.

Associations between gamebird releases and generalist predators

Article

Jul 2019

The release of more than 40 million captive‐bred pheasants and red‐legged partridges in Britain annually represents a significant addition to the potential food resource base for predators and scavengers. If this extra food availability subsidizes predator populations, gamebird releases could increase predation pressure on other wild birds, affecting their populations. Using three extensive datasets, we examined the spatial relationships between reared and free‐roaming gamebirds (pheasant Phasianus colchicus and red‐legged partridge Alectoris rufa), and explored spatial and temporal associations between these gamebirds and five species of avian predator (buzzard Buteo buteo, jay Garrulus glandarius, raven Corvus corax, magpie Pica pica and hooded Corvus cornix and carrion Corvus corone crows combined) in lowland rural Britain. Patterns of spatial variation in the abundance of free‐roaming gamebirds across Britain appear to be largely determined by gamebird releases, over and above any effects of land use or habitat. Predominantly positive associations between gamebird abundance (both reared and free‐roaming) and the abundance and inter‐annual population growth rates of predators tested suggest that large‐scale variation in avian predator populations may be positively affected by gamebird releases. Synthesis and applications. The positive associations between large‐scale gamebird release and predator populations shown here may have implications for prey populations if the releases cause increased predation pressure. If this occurs, game management could have an indirect negative impact on some prey species partially counteracting previously reported positive or benign effects of game management on wider biodiversity. Overall impacts of gamebird releases are likely to be determined by complex interactions between multiple factors, including induced predation pressure, better understanding of which would be possible with compulsory recording of releases and numbers of predators killed. Restriction of releases warrants further investigation and consideration as a potential conservation tool for wild bird populations.

Offspring defense by an urban raptor responds to human subsidies and ritual animal-feeding practices

Article

Full-text available

Oct 2018
PLOS ONE

There is a growing interest in the behavioural and life history mechanisms that allow animal species to cope with rapidly expanding urban habitats, which impose frequent proximity to humans. A particular case of behavioral bottleneck (i.e. conflicting interests) faced by animals in urban environments is how they will modulate the defence of their offspring against the potential danger represented by humans, an aspect that has received scarce research attention. We examined the nest defense against humans by a dense breeding population of a raptor, the Black Kite Milvus migrans, within the megacity of Delhi (India). Here, kites live on a diet dominated by human waste and meat offered through religiously motivated bird feeding practices. Nest defense levels increased with the number of offspring, and with the progression of the breeding season. Defense also intensified close to ritual-feeding areas and with increasing human waste in the streets, suggesting synergistic effects of food availability, parental investment, personality-boldness and habituation to humans, with consequent attenuation of fear. Thus, the behavioural response to a perceived threat reflected the spatial mosaic of activity of humans in the city streets, their cultural practices of ritual-feeding, and their waste-management. For synurbic species, at the higher-end spectrum of adaptation to an urban life, human cultural practices and attitudes may well be the most defining dimensions of their urban niche. Our results suggest that, after initial urban coloni-zation, animals may continue to adapt to the typically complex, heterogeneous environments of cities through fine-grained behavioural adjustments to human practices and activities.

Offspring defense by an urban raptor responds to human subsidies and ritual animal-feeding practices

Article

Full-text available

Oct 2018

There is a growing interest in the behavioural and life history mechanisms that allow animal species to cope with rapidly expanding urban habitats, which impose frequent proximity to humans. A particular case of behavioral bottleneck (i.e. conflicting interests) faced by animals in urban environments is how they will modulate the defence of their offspring against the potential danger represented by humans, an aspect that has received scarce research attention. We examined the nest defense against humans by a dense breeding population of a raptor, the Black Kite Milvus migrans, within the megacity of Delhi (India). Here, kites live on a diet dominated by human waste and meat offered through religiously motivated bird feeding practices. Nest defense levels increased with the number of offspring, and with the progression of the breeding season. Defense also intensified close to ritual-feeding areas and with increasing human waste in the streets, suggesting synergistic effects of food availability, parental investment, personality-boldness and habituation to humans, with consequent attenuation of fear. Thus, the behavioural response to a perceived threat reflected the spatial mosaic of activity of humans in the city streets, their cultural practices of ritual feeding, and their waste-management. For synurbic species, at the higher-end spectrum of adaptation to an urban life, human cultural practices and attitudes may well be the most defining dimensions of their urban niche. Our results suggest that, after initial urban colonization, animals may continue to adapt to the typically complex, heterogeneous environments of cities through fine-grained behavioural adjustments to human practices and activities.

Patterns of satellite tagged hen harrier disappearances suggest widespread illegal killing on British grouse moors

Article

Full-text available

Mar 2019

Identifying patterns of wildlife crime is a major conservation challenge. Here, we test whether deaths or disappearances of a protected species, the hen harrier, are associated with grouse moors, which are areas managed for the production of red grouse for recreational shooting. Using data from 58 satellite tracked hen harriers, we show high rates of unexpected tag failure and low first year survival compared to other harrier populations. The likelihood of harriers dying or disappearing increased as their use of grouse moors increased. Similarly, at the landscape scale, satellite fixes from the last week of life were distributed disproportionately on grouse moors in comparison to the overall use of such areas. This pattern was also apparent in protected areas in northern England. We conclude that hen harriers in Britain suffer elevated levels of mortality on grouse moors, which is most likely the result of illegal killing.

Plastic ingestion in an emaciated red kite (Milvus milvus) in England

Article

Jul 2022

The red kite (Milvus milvus) was successfully re‐introduced into England in 1989, although the population continues to face anthropogenic threats. In this report, we describe evidence of plastic ingested in the ventriculus of an adult male red kite that was emaciated. In addition, dried blood was found on the feathers overlying both wings, and subcutaneous haemorrhage was identified. Toxicology tests revealed toxic levels (>100 ng/g) of second‐generation anticoagulant rodenticides (difenacoum 3.0 ng/g, brodifacoum 734.9 ng/g) in the liver of this red kite. Three possible contributors to mortality were considered: starvation from the ingestion of plastic preventing normal digestion, collision‐related trauma and second‐generation anticoagulant rodenticide poisoning. This is the first report of plastic ingestion in a red kite. The case highlights the importance of carrying out postmortem examinations as part of post‐release health surveillance and identifies plastic ingestion as a potential anthropogenic threat facing the red kite population in England.

Onze anys de seguiment de rapinyaires forestals a la Segarra: 2007-2017

Article

Full-text available

May 2020

La situació general de les poblacions de rapinyaires forestals a Catalunya ha experimentat una millora en les darreres dècades, atribuïble fonamentalment a l'increment de la superfície boscosa. El seguiment de les poblacions d'astor (Accipiter gentilis), d'aligot comú (Buteo buteo) i d'àguila calçada (Hieraaetus pennatus) i, en menor mesura, d'esparver vulgar (Accipiter nisus) i d'àguila marcenca (Circaetus gallicus) entre 2007 i 2017 al sud de la Segarra i a la Baixa Segarra ha permès obtenir algunes dades sobre la situació actual d'aquestes espècies a la comarca. Els resultats obtinguts indiquen que durant el període de seguiment les poblacions d'astor, d'aligot comú i d'àguila calçada s'han mantingut més o menys estables. L'èxit reproductor de l'astor i de l'aligot comú ha estat relativament baix en comparació amb les dades històriques existents a la zona, mentre que en el cas de l'àguila calçada i l'àguila marcenca els valors es troben dins de la normalitat. És necessari seguir estudiant les poblacions d'aquests ocells per tal de determinar com responen davant de les pertorbacions i dels canvis naturals i antròpics que afecten els paisatges forestals actualment i en el futur. The situation of forest-dwelling raptors in Catalonia has improved over the last decades, mainly due to the increase of forested areas. The monitoring of populations of Northern Goshawk (Accipiter gentilis), Common Buzzard (Buteo buteo) and Booted Eagle (Hieraaetus pennatus) and, to a lesser extent, Eurasian Sparrowhawk (Accipiter nisus) and Short-Toed Eagle (Circaetus gallicus) between 2007 and 2017 in the south of the Segarra shire and Baixa Segarra has provided some data on the current status of the population of these species in the area. The results show that during the study period the populations of Northern Goshawk, Common Buzzard and Booted Eagle have remained quite stable. The reproductive success of Northern Goshawk and Common Buzzard is relatively low, in comparison with the historical data in the area, while in the case of Booted Eagle and Short-Toed Eagle figures are within normality. Further monitoring of these populations is required in order to assess how they will respond to natural and anthropogenic changes and disturbances that are currently affecting and will affect woodland in the future.

Anthropogenic pressures within the breeding range of the Hen Harrier Circus cyaneus in Ireland

Article

Mar 2020
BIRD STUDY

Capsule: Patterns in the frequency and co-occurrence of anthropogenic pressures associated with suitable breeding habitat for Hen Harriers Circus cyaneus demonstrates the need for specific, focussed management and policy options aimed at mitigating impacts on this threatened population. Aims: To describe anthropogenic pressures and threats in the upland breeding range of Hen Harriers and to explore their potential impacts on the declining Hen Harrier population. Methods: We used text mining, mixed-effects models, principal component analysis and clustering methods to explore anthropogenic pressures on suitable breeding and foraging habitats for Hen Harriers in Ireland, based on the 2015 national breeding Hen Harrier survey data. Results: Mixed-effects models described a strong influence of agriculture, forestry, predator activity, and recreational activities on survey areas that contained Hen Harrier territories. Cluster analyses described three discrete pressure clusters and showed consistent co-occurrence of independent pressures. Conclusions: Areas of suitable habitat for Hen Harriers in the uplands overlap with areas that experience anthropogenic pressures known to negatively impact on this vulnerable bird species. Combined with clear evidence for the co-occurrence of multiple pressures at a regional scale, this demonstrates a clear need for statutory agencies to consider the potential cumulative impacts of individual pressures when developing conservation strategies for Hen Harriers.

Науковий вісник Львівського національного університету ветеринарної медицини та біотехнологій імені С Specific peculiarity of the forensic veterinary expert conclusion structure according to the research of fowl corpse results

Article

Full-text available

Jun 2022

Yatsenko, І. V., & Kazantsev, R. H. (2021). Specific peculiarity of the forensic veterinary expert conclusion structure according to the research of fowl corpse results. Scientific Messenger The article identifies and systematizes some issues of the forensic veterinary expert conclusion structure according to the research of fowl carcass results. It is claimed that the sequence of fowl carcass examination results presentation is determined by a forensic veterinary expert with account the examination specifics, the object study state and the issues nature raised by the subject of examination appointment for the expert decision. It is shown that the peculiarity of its introductory part is a specific issues list raised for the forensic veterinary expert decision by the research subject. Mandatory elements of the "Research" section in the expert's conclusion is a statement of the individual documents study results in the proceedings and directly related to the examination (extract from the animal's health history, fowl ambulatory card, site inspection report, etc.), carcass registration data, results of its external and internal research according to certain algorithms description, results of additional researches (forensic chemical, histological, forensic toxicological, etc.), forensic veterinary diagnosis and the synthesizing part conclusion formulation. The final part of the expert's conclusion is the questions answer to the mentioned in the introductory part in a categorical or, as an exception, in a probable form. Be sure to indicate the damage nature or pathological changes, their location, the cause of fowl death, the causal relationship between the damage caused to the fowl health and the onset of its death. The appendices peculiarity is that they are drawn up in the photo tables form, which carry information about the fowl carcasses forensic veterinary examination stages, supplement and confirm the expert's opinion verbal part. Особливості структури висновку судово-ветеринарного експерта за результатами дослідження трупа птиці І. В. Яценко, Р. Г. Казанцев Державний біотехнологічний університет, м. Харків, Україна В роботі означено і систематизовано деякі питання структури висновку судово-ветеринарного експерта за результатами дослідження трупа птиці. Стверджується, що послідовність викладу результатів дослідження трупа птиці визначається судово-ветеринарним експертом, враховуючи особливості проведення експертизи, стану об'єкта дослідження і характеру питань, поставлених суб'єктом призначення експертизи на вирішення експерта. Показано, що особливістю його вступної частини є специфічний перелік питань, поставлених на вирішення судово-ветеринарному експерту суб'єктом призначення експертизи. Обов'язковими елементами розділу "Дослідження" у висновку експерта є виклад результатів дослідження окремих документів, що є в матеріалах провадження і безпосередньо стосуються експертизи (виписка з історії хвороби тварина, амбулаторна карта птиці, протокол огляду місця події тощо), реєстраційні дані трупа, описання результатів його зовнішнього та внутрішнього дослідження за визначеними алгоритмами, результати додаткових досліджень (судово-хімічні, гістологічні, судово-токсикологічні тощо), формулювання судово-ветеринарного діагнозу та складання синтезуючої частини висновку. Заключна частина висновку

Old World Vultures Reflect Effects of Environmental Pollutants Through Human Encroachment

Article

Full-text available

Jun 2022

African wildlife face challenges from many stressors including current and emerging contaminants, habitat and resource loss, poaching, intentional and unintentional poisoning, and climate‐related environmental change. The plight of African vultures exemplifies these challenges due to environmental contaminants and other stressors acting on individuals and populations that are already threatened or endangered. Many of these threats emanate from increasing human population size and settlement density, habitat loss from changing land use for agriculture, residential areas, and industry, and climate‐related changes in resource availability. Environmental chemicals that are hazardous include legacy chemicals, emerging chemicals of concern, and high‐volume‐use chemicals that are employed as weed killers and in other agricultural applications. Furthermore, there are differences in risk for species living in close proximity to humans or in areas affected by habitat loss, climate, and industry. Monitoring programs are essential to track the status of nesting pairs, offspring survival, longevity, and lifetime productivity. This is important for long‐lived birds, such as vultures, that may be especially vulnerable to chronic exposure to chemicals as obligate scavengers. Furthermore, their position in the food web may increase risk due to biomagnification of chemicals. We review the primary chemical hazards to Old World vultures and the interacting stressors affecting these and other birds. Habitat is a major consideration for vultures, with tree‐nesters and cliff‐nesters potentially experiencing different risks of exposure to environmental chemicals. The present review provides information from long‐term monitoring programs and discusses a range of these threats and their effects on vulture populations. Environ Toxicol Chem 2022;00:1–19.

Enhancing monitoring and transboundary collaboration for conserving migratory species under global change: The priority case of the red kite

Article

Full-text available

Sep 2022
J ENVIRON MANAGE

Calls for urgent action to conserve biodiversity under global change are increasing, and conservation of migratory species in this context poses special challenges. In the last two decades the Convention on the Conservation of Migratory Species of Wild Animals (CMS) has provided a framework for several subsidiary instruments including action plans for migratory bird species, but the effectiveness and transferability of these plans remain unclear. Such laws and policies have been credited with positive outcomes for the conservation of migratory species, but the lack of international coordination and on-ground implementation pose major challenges. While research on migratory populations has received growing attention, considerably less emphasis has been given to integrating ecological information throughout the annual cycle for examining strategies to conserve migratory species at multiple scales in the face of global change. We fill this gap through a case study examining the ecological status and conservation of a migratory raptor and facultative scavenger, the red kite (Milvus milvus), whose current breeding range is limited to Europe and is associated with agricultural landscapes and restricted to the temperate zone. Based on our review, conservation actions have been successful at recovering red kite populations within certain regions. Populations however remain depleted along the southern-most edge of the geographic range where many migratory red kites from northern strongholds overwinter. This led us to a forward-looking and integrated strategy that emphasizes international coordination involving researchers and conservation practitioners to enhance the science-policy-action interface. We identify and explore key issues for conserving the red kite under global change, including enhancing conservation actions within and outside protected areas, recovering depleted populations, accounting for climate change, and transboundary coordination in adaptive conservation and management actions. The integrated conservation strategy is sufficiently general such that it can be adapted to inform conservation of other highly mobile species subject to global change.

Población reproductora de milano real Milvus milvus L., 1758 en Gipuzkoa en 2020

Article

May 2022

A lo largo de lo que va de siglo se viene observando en Gipuzkoa un posible aumento de la población nidificante de milano real Milvus milvus. Si bien parcialmente esta realidad se ha asociado a un incremento en el esfuerzo de muestreo, el proceso de colonización y aumento poblacional de la especie en la provincia parece evidente. Así, de la ausencia de aves reproductoras dada según el censo de 2004 se pasó a algo más de 20 parejas durante el periodo 2014-2015. En un contexto de declive en muchas zonas de España, la realidad de la especie en Gipuzkoa supone, hasta cierto punto, un caso anómalo. En este contexto, durante los últimos años se ha invertido un esfuerzo notable en el seguimiento de la especie. Este artículo resume los resultados del seguimiento de milano real en Gipuzkoa, actualizado para la temporada de cría de 2020. Se detectaron 32 territorios (parejas). La distribución de estos nidos en la provincia no es uniforme, ya que se detecta una concentración más alta de ellos en el sector más sudoriental del territorio. Se registró un éxito de cría alto (85,2%), así como una productividad de 2,0 pollos/pareja (rango: 1-3; 1,4 pollos/pareja se sumamos, también, las parejas que no llegaron a reproducirse), lo que confirma que Gipuzkoa es una zona buena para la reproducción de la especie. Esto puede jugar un papel clave no sólo en un posible proceso de consolidación de la población en la región, sino de colonización y reforzamiento poblacional en regiones limítrofes. Siendo Gipuzkoa una provincia muy forestal, el milano real tiende a ocupar zonas con mayor superficie relativa de hábitats abiertos, lo cual pone de relieve el valor de la campiña en la conservación de la especie. En este contexto, es importante impulsar el desarrollo de estudios orientados a determinar el uso del territorio así como las características que definen qué tipo de campiña es óptima para el milano real.

Causes, temporal trends, and the effects of urbanization on admissions of wild raptors to rehabilitation centers in England and Wales

Article

Full-text available

Apr 2022

Data from wildlife rehabilitation centers (WRCs) can provide on-the-ground records of causes of raptor morbidity and mortality, allowing threat patterns to be explored throughout time and space. We provide an overview of native raptor admissions to four WRCs in England and Wales, quantifying the main causes of morbidity and mortality , trends over time, and associations between threats and urbanization between 2001 and 2019. Throughout the study period, 14 raptor species were admitted totalling 3305 admission records. The Common Buzzard (Buteo buteo; 31%) and Tawny Owl (Strix aluco; 29%) were most numerous. Relative to the proportion of breeding individuals in Britain and Ireland, Peregrine Falcons (Falco peregrinus), Little Owls (Athene noctua), and Western Barn Owls (Tyto alba) were over-represented in the admissions data by 103%, 73%, and 69%, respectively. Contrastingly Northern Long-eared Owls (Asio otus), Western Marsh Harriers (Circus aeruginosus), and Merlin (Falco columbarius) were under-represented by 187%, 163%, and 126%, respectively. Across all species, vehicle collisions were the most frequent anthropogenic admission cause (22%), and orphaned young birds (10%) were most frequent natural cause. Mortality rate was highest for infection/parasite admissions (90%), whereas orphaned birds experienced lowest mortality rates (16%). For one WRC, there was a decline in admissions over the study period. Red Kite (Milvus milvus) admissions increased over time, whereas Common Buzzard and Common Kestrel admissions declined. There were significant declines in the relative proportion of persecution and metabolic admissions and an increase in orphaned birds. Urban areas were positively associated with persecution, building collisions, and unknown trauma admissions, whereas vehicle collisions were associated with more rural areas. Many threats persist for raptors in England and Wales, however, have not changed substantially over the past two decades. Threats associated with urban areas, such as building collisions, may increase over time in line with human population growth and subsequent urban expansion.

Use of poisoned baits against wildlife. A retrospective 17-year study in the natural environment of Extremadura (Spain)

Article

Mar 2022
ENVIRON POLLUT

This study reports the results obtained from toxicological analyses of different types of baits referred to the laboratory of the Toxicology Area (Faculty of Veterinary Medicine, Cáceres, Spain) over a 17-year period (2002–2018). These baits were suspicious materials found in the environment of the region of Extremadura (Western Spain), where such malpractices are a problem to be addressed, as wide livestock farming and hunting activities are combined with a significant wealth of wildlife (especially birds of prey). A total of 246 baits, including 32 commercial chemical products to be used in baits, were analysed. Samples from 183 cases were received and classified according to the material used for their preparation and the toxic substance found. Overall, the most common bait consisted of meat preparations (56.3% of cases) intended to eliminate predators considered ‘annoying’ for livestock and hunting practices, such as carnivores and scavengers. It should be noted that contact baits (as fenthion-impregnated perches) were also detected (7.6%). Regarding the substances detected, anticholinesterase compounds (organophosphates and carbamates) were the most commonly used substances for the preparation of baits (detected in 85.3% of positive baits). Moreover, 8% of the positive baits presented more than one toxic substance in their composition. Due to the types of toxic compounds and the methods used to prepare the baits, this study shows that the malicious use of highly toxic substances in the environment to kill wildlife is a common and current issue and poses a serious risk to different species.

The illegal shooting and snaring of legally protected wolves in Poland

Article

Full-text available

Dec 2021
BIOL CONSERV

In central Europe, wolves Canis lupus prey on wild ungulates - main game species and occasionally kill livestock. The recovery of wolf population across the continent coincides with an increasing incidence of illegal killing, which level remains unknown. We analysed the illegal killing of wolves in Poland, where the species is strictly protected since 1998. We opportunistically collected data on wolves illegally shot and snared from 2002 to 2020, revealing their geographical extent and sex and age structure. Furthermore, we estimated their mortality rate due to illegal shooting on the basis of 16 GPS/GSM collared individuals between 2014 and 2020. We recorded 54 illegally shot and 37 snared wolves. The majority (63.7%) were killed between 2017 and 2020, mostly in Western Poland. The sex structure was similar between shot and snared individuals. In both groups, the wolves over one-year old prevailed, although there were 18 pups among shot wolves. We identified 6 shot and 3 snared breeders. Out of 16 GPS/GSM collared individuals, six were shot giving the mortality rate of 0.33 per year. Simulations revealed that the pooled number of wolves illegally shot in Poland annually, is between 147 and 1134 (99% highest density interval) or 216 and 1000 (95%). In six out of seven cases, in which the person who shot a wolf was eventually sentenced, hunters were responsible. We conclude that the present regulations concerning the prevention of illegal killing, pursuing and punishing the perpetrators of the illegal killing of wolves, require urgent improvements in order to effectively mitigate the problem.

Differential survival throughout the full annual cycle of a migratory bird presents a life-history trade-off

Article

Full-text available

Mar 2021

1. Long-distance migrations are among the most physically demanding feats animals perform. Understanding the potential costs and benefits of such behaviour is a fundamental question in ecology and evolution. A hypothetical cost of migration should be outweighed by higher productivity and/or higher annual survival, but few studies on migratory species have been able to directly quantify patterns of survival throughout the full annual cycle and across the majority of a species’ range. 2. Here, we use telemetry data from 220 migratory Egyptian vultures Neophron percnopterus, tracked for 3,186 bird months and across approximately 70% of the species’ global distribution, to test for differences in survival throughout the annual cycle. 3. We estimated monthly survival probability relative to migration and latitude using a multi-event capture–recapture model in a Bayesian framework that accounted for age, origin, subpopulation and the uncertainty of classifying fates from tracking data. 4. We found lower survival during migration compared to stationary periods (β = −0.816; 95% credible interval: −1.290 to −0.318) and higher survival on non-breeding grounds at southern latitudes (<25°N; β = 0.664; 0.076–1.319) compared to on breeding grounds. Survival was also higher for individuals originating from Western Europe (β = 0.664; 0.110–1.330) as compared to further east in Europe and Asia, and improved with age (β = 0.030; 0.020–0.042). Anthropogenic mortalities accounted for half of the mortalities with a known cause and occurred mainly in northern latitudes. Many juveniles drowned in the Mediterranean Sea on their first autumn migration while there were few confirmed mortalities in the Sahara Desert, indicating that migration barriers are likely species-specific. 5. Our study advances the understanding of important fitness trade-offs associated with long-distance migration. We conclude that there is lower survival associated with migration, but that this may be offset by higher non-breeding survival at lower latitudes. We found more human-caused mortality farther north, and suggest that increasing anthropogenic mortality could disrupt the delicate migration trade-off balance. Research to investigate further potential benefits of migration (e.g. differential productivity across latitudes) could clarify how migration evolved and how migrants may persist in a rapidly changing world.

Raptors, racing pigeons and perceptions of attacks

Article

Full-text available

Jul 2021
EUR J WILDLIFE RES

Raptors are often the cause of human-wildlife conflict because they may predate economically valuable species, and it is the perceived extent of predation that may augment conflict between raptors and people who keep and race pigeons. This study uses data obtained through questionnaires and an online raptor-attack reporting feature to investigate the frequency of racing pigeon losses and the perceptions of pigeon fanciers. Responses suggest that those who kept more pigeons and entered more races lost a higher proportion of pigeons. Losses were also influenced by the predatory species: sparrowhawks (Accipter nisus) were more likely to attack pigeons at lofts, whilst peregrines (Falco peregrinus) were more likely to attack pigeons during training, with patterns linked to the raptors' breeding seasons. Pigeon fanciers were almost unanimous in their perception that raptors threaten the future of the hobby. Previous studies show that only a small proportion of racing pigeons are likely to be lost to raptors, yet pigeon fanciers believe that raptors are the main cause of losses, highlighting a possible mismatch between the perceived and actual causes of loss. This misconception may be a main source of this human-raptor conflict, so educating pigeon fanciers about the true impact of raptors could help to alleviate the issue. A shift in the beginning of the pigeon racing season by one month, and careful sighting of pigeon lofts in gardens, are also recommended in order to reduce raptor attacks.

Drivers of Departure and Prospecting in Dispersing Juvenile Red Kites (Milvus milvus)

Article

Jan 2020

Patrick Scherler

Natal dispersal of juvenile birds is a fundamental mechanism that shapes population dynamics and enables gene flow amongst populations. It consists of the onset of dispersal (departure from natal home range), a transience stage and an informed settlement decision. Prospecting behaviour during the transience stage allows juvenile birds to gather information for making settlement decisions, and variation in this prospecting behaviour might affect their survival. In migratory species, prospecting after the onset of dispersal is interrupted by autumn migration and only continues after their return to known or new habitats in the breeding area after spring migration. Timing and duration of migration phases throughout the annual cycle might therefore affect the amount of time allocated to the prospecting behaviour. Characteristics of prospecting behaviour might also be affected by individual traits, as well as by carry-over effects of natal home range quality and information acquired in previous prospecting phases. Environmental gradients are expected to shape population range margins through effects on reproductive output and differential dispersal decisions. In this thesis, I used the red kite (Milvus milvus) as study system to investigate how natal home range quality, parental breeding decisions and individual traits affect the onset of dispersal (Chapter 1). I then identified dispersal and migration phases throughout the annual cycle (pre-migration prospecting, first autumn migration, non-breeding period, first spring migration, post-migration prospecting and second autumn migration) and assessed temporal carry-over effects to subsequent phases (Chapter 2). This allowed me to investigate the role of natal habitat quality, individual traits and previous prospecting experience on post-migration prospecting behaviour (Chapter 3). In a population of red kites in Western Switzerland, I used solar-powered GPS-GSM-UHF transmitters to track large samples of juveniles from fledging throughout the full first annual cycle. Juveniles from nests along an elevational gradient were chosen and I performed a food supplementation experiment during the nestling phase to disentangle the effect of an elevational gradient in food availability from other elevational effects, which are often correlated. The food supplementation experiment also allowed investigating whether additive or interacting effects of weather conditions and food availability affect reproductive traits (Chapter 4). Food availability in this opportunistic scavenger might be influenced by anthropogenic food sources, complementing natural prey availability. We therefore quantified anthropogenic food supply by private feeding (Chapter 5), as well as the effect of urbanization on the composition of scavenger assemblages and on the ecological function of carcass removal in our study area (Chapter 6). The thesis can be thematically subdivided into a first part focussing on influences on dispersal behaviour (Chapters 1-3) and a second part investigating use and availability of food resources and the impact of food resources and weather conditions on reproductive traits (Chapters 4-6). In Chapter 1, I showed that parental choice of the breeding site and timing of breeding affect the onset of dispersal. Supplementary fed juveniles departed earlier than control juveniles, and late-hatched birds reduced the duration to departure rather than keeping departure age constant. Therefore, I conclude that favourable food availability at the natal site allows for early departure and that late hatching dates are compensated with young departure age. An early onset of dispersal seems to yield higher fitness benefits than prolonging the period in the natal home range. In Chapter 2, I showed that the heterogeneity in movement characteristics of migration and dispersal is complicating the clear distinction of the two behaviours. I also showed that timing and duration of autumn migration, as well as the duration of spring migration are consistently short and synchronized. This implies that the duration of the pre-migratory prospecting phase is mainly determined by the departure from natal home range, whilst the timing of the short spring migration depends on a trade-off between allocating time to staying at the non-breeding sites and time to invest in post-migration prospecting. The identification of pre-migration and post-migration prospecting phases within the annual cycle allows for quantifying phase-specific survival rates and a better understanding of informed dispersal in migrant birds. In Chapter 3, I investigated how individual traits, parental habitat quality and time previously invested in prospecting behaviour affects prospecting behaviour after return from spring migration. I found that males and individuals fledged at low altitudes are more likely to return to the natal home range. Sex differences in prospecting behaviour suggest that males profit more from returning to the natal home range than females. Individuals born in high altitudes prospected at lower elevation than their natal home range. They might not return to their natal home range due to current or previously experienced adverse environmental conditions, which suggests a preference for prospecting at low elevations. These differences in prospecting behaviour are likely to affect future settlement decisions in that lower elevations are selected and hence contribute to the conservation of elevational range margins. In Chapter 4 we showed that food availability and weather condition do not interact but influence reproductive traits additively. Weather influenced the reproductive output already during incubation and might be the key factor regulating the reproductive output. Nevertheless, high food availability, either experimentally or naturally increased, improved all four investigated reproductive parameters. It therefore considerably affects the reproductive output and nestling body condition. This shows the importance of food availability and weather conditions in the parental habitat in shaping fledging body condition as a cornerstone of post-fledging behaviour. Food availability in the natal home range shapes fledging body condition and affects subsequent dispersal decisions. For opportunistic facultative scavengers, such as red kites, anthropogenic food sources and carrion availability might be important to counterbalance adverse natural prey availability. In Chapter 5, we quantified the extent of anthropogenic feeding of red kites in urban and rural environments in our study area based on a systematic survey. We found that anthropogenic feeding is a widespread phenomenon in Western Switzerland, especially in rural environments. In Chapter 6, we assessed how red kites contribute to carrion removal in the scavenger community. We found that they remove carrion in both rural and urban environments and that they adjust faster than any other scavenger to repeated availability of carrion at the same location. The findings of these two chapters indicate the importance of locations with predictable carrion availability such as anthropogenic feeding sites. The amount of predictable food made available for red kites is likely to buffer fluctuations in natural prey availability, which might be crucial for breeding success and informed settlement decisions (habitat selection), as well as for survival rates and migration behaviour throughout the annual cycle. This PhD thesis shows (1) that natal environment and thus parental habitat selection decisions affect timing and duration of dispersal phases throughout the annual cycle and (2) that effects of natal environment and early prospecting characteristics carry-over to the subsequent prospecting behaviour as part of informed dispersal. Whilst elevation of the parental habitat largely affects prospecting decisions, food availability in the parental habitat is a minor driver of prospecting behaviour but an important driver of reproductive output. The understanding of factors affecting the reproductive output and mechanisms in the first part of the transience stage enables us to further investigate informed settlement decisions, resulting fitness consequences and spatial population structuring of migratory bird species. This thesis therefore lays a foundation for a deeper understanding of the role of natal dispersal in the formation of elevational range margins and contributes to the identification of the drivers of the recent range expansion of red kites in Switzerland. Keywords – behavioural ecology, natal dispersal, migration, annual cycle, departure, transience, natal environment, elevation, carry-over effects, reproductive traits, food availability, anthropogenic feeding, carrion, scavenger community, red kite, Milvus milvus

Contrasting long‐term trends in age‐specific survival of Peregrine Falcons (Falco peregrinus) in Britain using smoothed estimates of recovery probabilities

Article

Feb 2021

Peregrine Falcons Falco peregrinus are an iconic species of long‐standing conservation concern as a result of historic patterns of persecution, and dramatic pesticide‐related population declines in many populations during the second half of the 20th century. While the role of reduced productivity in these declines is well known, temporal patterns in survival are much less well characterised. We estimate survival probabilities for Peregrines in Britain in the period 1975 to 2018 from reports of ringed birds found dead, using a non‐parametric smoothing spline to account for non‐linear temporal variation in recovery probabilities. During this time the population increased from around 350 pairs to 1628 pairs. There was little evidence of a temporal trend in the survival probabilities of adult birds since the mid‐1970s, but survival of first‐year birds appears to have decreased. Our estimates suggest that increases in the breeding population are further limited by unreported sources of mortality or by density dependent processes and highlight the need for better data on immature survival and recruitment. Modelling recovery rates using a spline, rather than independent annual values, improved estimation efficiency with lower credible intervals obtained for the adult annual estimates.

Main mortality factors for the Eastern Imperial Eagle (Aquila heliaca Savigny, 1809) in Bulgaria

Article

Full-text available

Nov 2020

The Eastern Imperial Eagle is a globally threatened species, represented with not more than 35–40 pairs in Bulgaria. As a facultative scavenger feeding on carcasses and parts of dead domestic and wild animals, this species is extremely vulnerable to poisonous baits and toxic agents, intentionally or accidentally set up in its food. The present study identified electrocution and poisoning as the main mortality factors for the eagles in Bulgaria. We analysed a total of 56 cases among which 44 cases were related to the mortality of non-territorial eagles in different age classes, and we found 12 dead or distressed territorial birds recorded between 1992–2019. The main mortality factor was electrocution, accounted for 30.4% of fatalities. The poisoning was the cause of mortality in 12.5% of the non-territorial and 10.7% of the breeding birds. Some of the cases were laboratory confirmed as intoxication, while the others, based on the history, clinical symptoms and field evidence, indicated poisoning. The most commonly used toxic agents were anticholinesterase’s inhibitors. As a result of a timely therapy applied to the live birds found in distress with symptoms of poisoning, six eagles were successfully treated and released back in the wild. We found that mortality of eagles depended on the age of birds, breeding or dispersal grounds, while season had no significant effect.

The impacts of non-native gamebird release in the UK: an updated evidence review

Technical Report

Full-text available

Oct 2020

Mapping the conflict of raptor conservation and recreational shooting in the Batumi Bottleneck, Republic of Georgia

Article

Full-text available

Jun 2018

Illegal use of natural resources threatens biodiversity and often leads to conservation conflicts between affected parties. Such a conflict is emerging in the Batumi Bottleneck in the Republic of Georgia, where every autumn more than one million migrating birds of prey funnel above a handful of villages, and where thousands of these birds fall victim to illegal shooting. As a first step towards resolving this conflict, utilizing semi-structured interviews, we map the goals and opinions of relevant stakeholders associated with raptor migration in the bottleneck. Our results show that most stakeholders, except some local hunters, are on common ground considering the shooting unacceptable, but articulate different preferences concerning a solution, which hinged on institutional and enforcement issues. The hunters expressed a wide spectrum of responses concerning their involvement and motivation in raptor shooting, the role and importance of hunting in their lives, and preferred mitigation actions. The most urgent issues to be addressed via conservation actions are the wide-scale lack of awareness of the conflict, the potential loss of species, and the risk of conflict escalation.

Experimental diversionary feeding of red kites Milvus milvus reduces chick predation and enhances breeding productivity of northern lapwings Vanellus vanellus

Article

Full-text available

Aug 2021
J NAT CONSERV

For ground-nesting and colonial bird species, predation of eggs and chicks can exert a strong negative effect on population growth and recovery. For declining populations of waders breeding on lowland wet grassland, predation management tools are available to reduce the impacts of mammalian predators (e.g. lethal control, exclusion), but potential solutions are limited when raptors, which are often themselves protected by law and not easily excluded, are responsible for predation. Diversionary feeding (DF), where predators are provided with alternative food to replace the target prey species in their diet, has been tested successfully by providing food close to nesting raptor pairs to target specific individuals. Where many individuals are involved in predation at a single prey colony, or where locating or accessing nests is difficult, provisioning DF close to the focal prey colony may be a more practical solution. Here, we test the efficacy of providing DF in this way to reduce predation by red kites, a reintroduced and increasingly abundant protected raptor in the UK, on the chicks of northern lapwing, an internationally declining wader species. We conducted a five-year field experiment, comparing kite predation rates and breeding productivity of lapwings in years before, during and after DF. Rates of kite predation on lapwing chicks were substantially and significantly reduced in DF years, due to the successful elimination of a May-June peak in kite predation by DF which coincided with the kite chick provisioning and lapwing chick rearing periods. These annual reductions in kite predatory strike rates were concurrent with marked increases in overall annual lapwing productivity, which more than doubled on average in DF years, and were on a scale sufficient to facilitate lapwing population recovery. DF attracted other potential predators of lapwing eggs and chicks, and more kites were attracted to feeding stations than were initially targeted by DF, but neither had any measurable impact on lapwing breeding success during DF years or after its cessation. With increasing populations of many raptor species, predator-prey conservation conflicts are expected to increase. DF proved to be a highly effective predation management tool for a high-density wader colony on lowland wet grassland where intensive kite predation limited breeding success. Although evaluation of the effects of using DF continuously over several years is needed, targeting multiple predator individuals close to the focal prey of conservation concern may be an important predation management tool where accessing individual raptors at nest sites is impractical.

“If it flies, it dies”: Profit, workplace pressure and Bird of Prey persecution

Article

Jun 2021
J RURAL STUD

Persecution has continued to negatively impact the density and range of many Bird of Prey (raptor) species, both nationally and internationally, despite existing legal protection. Departing from the relatively small body of statistical analyses indicating elevated raptor mortality in proximity to shooting estates, this qualitative study draws on in-depth interviews with retired (hence, free from employment pressure) gamekeepers. New insights and findings are unfolded into the nature and extent of employment-related pressures (from employers) to commit raptor persecution. The findings offer a new narrative in the discourse on the problem, revealing that economic, community and lifestyle pressures co-exist within the gamekeeping industry. It is argued that regulatory design and enforcement strategy and tactics should be mindful of these pressures in order to reduce raptor persecution in both individual criminal liability and vicarious liability settings.

Abundance decline in the avifauna of the European Union reveals cross‐continental similarities in biodiversity change

Article

Full-text available

Nov 2021

Although global assessments provide evidence of biodiversity decline, some have questioned the strength of the evidence, with local assemblage studies often showing a more balanced picture of biodiversity change. The multifaceted nature of biodiversity and imperfect monitoring datasets may partially explain these findings. Here, using an extensive dataset, we find significant biodiversity loss in the native avifauna of the European Union (EU). We estimate a decline of 17–19% in the overall breeding bird abundance since 1980: a loss of 560–620 million individual birds. Both total and proportional declines in bird numbers are high among species associated with agricultural land. The distribution of species’ population growth rates (ln) is centered close to zero, with numerical decline driven by substantial losses in abundant species. Our work supports previous assessments indicating substantial recent biodiversity loss and calls to reduce the threat of extinctions and restore species’ abundances, for the sake of nature and people.

The RSPB Centre for Conservation Science: developing evidence-based solutions to address the biodiversity crisis

Article

Jan 2020

R Gregory

We live in an era thought by many to represent the sixth mass extinction event, but the first driven by human activity alone: the ‘anthropocene’ (Johnson et al. 2017). There is growing recognition that the fate of nature and humankind are closely interlinked, and that nature underpins our economies, our health and social wellbeing. Against the backcloth of biodiversity in crisis, the RSPB Centre for Conservation Science was established in 2014. Its aim is to identify, provide and interpret the scientific evidence needed to help the RSPB and others to make informed decisions on biodiversity conservation and the environment. This paper, presented originally as the Bernard Tucker Memorial Lecture in 2018, highlights the work of the Centre and introduces its adopted model of conservation. The paper is illustrated with examples of conservation action and science from the UK and overseas.

Dispersal and philopatry in Central European Red Kites Milvus milvus

Article

Jan 2022

In a study of the extent and timing of Red Kite Milvus milvus dispersal movements from Central Europe (Austria, the Czech Republic and Slovakia) using GPS telemetry, we found support for the hypothesis that Red Kite dispersal, including migration behaviour, is dependent on both age and sex. Examination of the tendency to stay in, or return to, a particular area in Red Kites indicated that, while part of the population remained in the natal area, most migrated to overwintering sites across a broad belt of southern European sites stretching from the Iberian Peninsula to the Balkans. Red Kites first bred at 2 years old, i.e. in their 3rd calendar year. Migration routes were significantly longer in females than males, while natal philopatry was significantly higher in males than females. The lengths of single-year migration routes decreased significantly over consecutive years, and breeding philopatry increased significantly in cases where previous breeding was successful.

Conservation Threats and Priorities for Raptors Across Asia

Chapter

Full-text available

Jul 2018

With long coastlines and some of the world’s most important rivers, mountain ranges, high-altitude plateaus, and islands, Asia is the largest and most populous continent in the world (Lyde 1904; Spencer 1954; Population Reference Bureau 2016). Asia supports all major terrestrial ecosystems and all major climatic types (Galloway et al. 1998; Braimoh and Huang 2015). These include barren ice fields and taigas in North Asia; boreal forests and cold deserts in West, Central, and East Asia; temperate and tropical forests (wet and dry) in East and Southeast Asia; and grasslands in Central and South Asia (Udvardy 1975; Braimoh and Huang 2015). Together, the ecoregions of Asia foster some of the greatest biodiversity on Earth, including six (24%) of 25 global biodiversity hotspots (Myers et al. 2000).

The status of the Hen Harrier, Circus cyaneus, in the UK and Isle of Man in 2010

Article

Full-text available

Oct 2013
BIRD STUDY

Capsule The fourth national survey of Hen Harrier showed that the population in the UK and the Isle of Man declined significantly between 2004 and 2010. Aim To estimate the size of the breeding Hen Harrier population (with associated 95% confidence intervals) in the UK and Isle of Man, constituent countries and Scottish regions, in 2010 and calculate population change since previous surveys in 1998 and 2004. Methods Complete surveys were made of 10-km squares likely to be occupied by breeding Hen Harriers in England, Wales, Northern Ireland and the Isle of Man, using standard methods developed for previous national surveys. In Scotland, a ‘census’ area was non-randomly selected for survey by volunteers, and randomly selected squares were surveyed in two strata covering the rest of the known range. Results The UK and Isle of Man Hen Harrier population was estimated at 662 territorial pairs (95% confidence interval (CI): 576–770), a significant decline of 18% since 2004. Scotland holds the bulk (76%) of the population (505 territorial pairs; 95% CI: 417–612), with smaller numbers in Northern Ireland (59 pairs), Wales (57 pairs), the Isle of Man (29 pairs) and England (12 pairs). Declines of 49% and 20% were observed in the Isle of Man and in Scotland, respectively, whereas the Welsh population increased by 33%. A significant decrease was recorded in numbers of pairs using young and mature plantation forest in Scotland. Conclusion The breeding population of Hen Harriers in the UK and Isle of Man declined between 2004 and 2010. Notable decreases in Scotland and the Isle of Man may be related to habitat change and illegal persecution. Illegal persecution continues to limit the population size of harriers in England to very low levels.

Status of the Hen Harrier Circus cyaneus in the UK and Isle of Man in 2004, and a comparison with the 1988/89 and 1998 surveys: Capsule The population of breeding Hen Harriers in the UK and Isle of Man increased between 1998 and 2004, although country and regional trends differed

Article

Full-text available

Jul 2007
BIRD STUDY

Aims To estimate the size of the UK and Isle of Man Hen Harrier breeding population in 2004, and to compare this with previous estimates made in 1988/89 and 1998. Methods Surveys were carried out in core and a stratified random sample of 10-km squares throughout the known range, using the same methods as in the 1988/89 and 1998 national surveys. Results There were an estimated 806 territorial pairs in the UK and Isle of Man in 2004, a significant 41% increase from the 1998 estimate of 570 pairs. Increases were found throughout, with the exception of south and east Scotland and England, where numbers decreased. Scotland held 79% of the UK and Isle of Man breeding population in 2004, and 10% of Scottish pairs were associated with non-moorland habitats, such as mature conifer plantations and scrub/brash. Conclusions There was a substantial increase in the breeding population in most regions of the UK and Isle of Man between 1998 and 2004, possibly aided by increased use of non-moorland habitats. However, populations declined in upland areas of southern and eastern Scotland and northern England. Continuing illegal persecution arising from perceived conflicts between breeding Hen Harriers and driven grouse shooting may be a major cause of these regional declines.

Philopatry and Population Growth of Red Kites, Milvus milvus, in Wales

Article

Full-text available

Sep 1994
Proc Biol Sci

Between 1946 and 1993, the number of territorial red kites, which form an isolated relict population in mid-Wales, has increased from 7 pairs to 113 pairs. Population growth has been approximately exponential at a mean rate of 5% per year. Breeding success was generally poor, but improved from an average of 0.53 young per pair in 1946-1960 to 0.71 young per pair in 1991-1993. Annual losses from the whole population (including juveniles) was estimated during 1946-1960 at 22%, reducing to 11% during 1961-1993. As the population grew, the area used for breeding expanded slowly. Despite wandering widely in their first year, birds returned to breed close to their natal area. For the most part, they expanded their breeding range progressively on a `rolling front', rather than striking out into distant unoccupied areas.

Extensive predator persecution caused by population crash in a game species: the case of Red Kites and rabbits in Spain

Article

Full-text available

May 1998
BIOL CONSERV

The European rabbit Oryctolagus cuniculus, an important game species in Spain, has declined sharply since the arrival of haemorrhagic disease in 1988. As a consequence of this decline, it appears that illegal and extensive persecution of predators has increased. We have assessed the impact of this persecution on red kites Milvus milvus. Around 90% of the populations studied have declined during the last 3–10 years, and the species' range has been reduced since 1980, particularly in high rabbit density areas (those most valuable for hunters). Currently, stable or increasing populations of red kites are located in areas of low rabbit density. Their abundance in areas of high rabbit density is similar to that recorded during the 1970s, when, after the spread of myxomatosis over Spain, government-sponsored campaigns of vermin extermination were carried out. Although red kites cannot be considered important predators of rabbits, they are disproportionally suffering the effects of human persecution, because of their susceptibility to shooting and poisoning, and a lack of understanding among hunters. We discuss the management strategies that might be used during population crashes of game species to avoid unjustified persecution of predators.

Breeding status of the Red Kite Milvus milvus in Britain in 2000

Article

Full-text available

Mar 2010
BIRD STUDY

Capsule The first co-ordinated Red Kite survey across Britain since the reintroduction programme began in 1989, yields 430 breeding pairs. Aims To estimate the current size and extent of the British breeding population. Methods A complete census of the populations in East Midlands, Yorkshire, central and north Scotland was undertaken, while in Wales and the Chilterns, populations were surveyed using a stratified sample of tetrads. Breeding and territorial pairs were identified. Results The survey indicated that there were 430 breeding pairs in Britain (95% CIs, 372–490). There were 259 breeding pairs in Wales (95% CIs, 200–318) and 109 (95% CIs, 96–124) in the Chilterns. Elsewhere, 16 breeding pairs were located in East Midlands, three in Yorkshire, seven in central Scotland and 33 in north Scotland. An additional three pairs were recorded in southern England, away from the main population centres. Conclusion The 2000 survey provides a baseline against which to measure future changes in Red Kite populations in Britain, using standard, repeatable methods.

Growth and demography of a re‐introduced population of White‐tailed Eagles Haliaeetus albicilla

Article

Full-text available

Feb 2009
IBIS

White-tailed Eagles Haliaeetus albicilla became extinct in Britain in 1918 following prolonged persecution. Intensive conservation efforts since the 1970s have included the re-introduction of the species to Britain through two phases of release of Norwegian fledglings in western Scotland in 1975–85 and 1993–98. Population growth and breeding success have been monitored closely to the present day, aided by the use of patagial tags to individually mark most released birds as well as a high proportion of wild-bred nestlings. This study reviews the growth and demography of this re-introduced population, and makes comparisons with other European populations. For the first time, we compare the demographic rates of released and wild-bred birds in the Scottish population. Breeding success in the Scottish population has increased over time as the average age and experience of individuals in the population have increased, and success tends to be higher where one or both adults are wild-bred. Current levels of breeding success remain low compared with some other populations in Europe, but similar to those in Norway where weather conditions and food availability are likely to be most similar. Survival rates in Scotland are similar to those recorded elsewhere, but survival rates of released birds are lower than those of wild-bred birds, especially during the first 3 years of life. Despite the effect of lower survival rates of released birds in limiting overall population growth rate, the recent rate of growth of the Scottish population remains high relative to other recovering populations across Europe. Differences in demographic rates of wild-bred and released birds suggest that in future re-introduction programmes, steps to maximize the success and output of the earliest breeding attempts would help ensure the most rapid shift to a population composed largely of wild-bred birds, which should then have a higher rate of increase.

The association of grouse moor in Scotland with the illegal use of poisons to control predators

Article

Full-text available

Dec 2003
BIOL CONSERV

In the UK uplands, there is a conflict between the maintenance of high densities of red grouse (Lagopus lagopus scoticus) for sporting shoots and the conservation of birds of prey on grouse moors where shoots take place. Several authors have indicated that as a result of this conflict, illegal use of poisoned baits to control predators is more likely to occur on grouse moors, but this association has not been examined formally. Mapping a form of land management unique to grouse moors (‘strip muirburn’), we use a GIS analysis to show that records of illegal poison use from 1981 to 2000 were disproportionately associated with grouse moors in Scotland. The association between poisoning incidents in the uplands and grouse moors was stronger in later years of the study period. It is suggested that this was at least partly due to a decline in the illegal use of poisons away from grouse moors. There was no evidence of any temporal decline in poisoning incidents on grouse moors over the study period. This research indicates that illegal methods for controlling predators (including protected birds of prey) are associated with traditional field sports and points to the need for management action.

The effects of persecution on age of breeding and territory occupation in Golden Eagles in Scotland

Article

Full-text available

Jul 2004
BIOL CONSERV

Several studies have documented negative effects of persecution by humans on the population dynamics of large birds of prey. Several areas have seen a reduction in persecution in modern times, but the demography of large raptors still makes these birds vulnerable to such effects. In a GIS analysis, utilising data collected during two national censuses of the golden eagle Aquila chrysaetos in Scotland and contemporary data on the distribution of poisoning incidents (a common method of raptor persecution in Scotland), we show that persecution was associated with a reduction in the age of first breeding, territory vacancies, and the use of territories by non-breeding immatures. Persecution was therefore reducing adult survival and distribution and was probably creating ecological traps that attract mobile immatures, increasing subadult mortality in birds that may originate from persecution-free areas. Mapping a form of land management unique to moors managed for red grouse Lagopus lagopus scoticus shooting, where most poisoning occurs, we also show similar associations between golden eagle demography and grouse moor management. As such, persecution may be having a major impact on the golden eagle population of Scotland, since it occurs over a wide area and at least in some areas has continued unchecked over many decades.

Modelling the effects of persecution on population dynamics of Golden Eagles in Scotland

Article

Full-text available

Oct 2004
BIOL CONSERV

We used observations of the age structure and breeding productivity of the Scottish population of golden eagles Aquila chrysaetos together with the classic theory of population dynamics to derive current `unmanipulated' estimates of life history parameters. We then used regional differences in age structure associated with differences in persecution intensity to derive estimates of prospective `persecution-free' life history parameters. The different parameter combinations were entered into a population model to simulate their effects on the number of occupied territories over time. Most simulations suggested that with unmanipulated demographic parameters the population should decline. The disparity between these predictions and the observed apparent stability in occupied territories was ascribed to the buffering effect of a lowering in age of breeding in areas where persecution is most intense and that more favourable parameter estimates within the estimated limits may be more realistic. The results indicated, nevertheless, that currently the population is vulnerable to decline as also suggested by the apparent lack of adults to occupy vacant territories. In the absence of the estimated 3–5% annual adult mortality through persecution, modelling suggested the population would increase. Removing estimated effects of persecution on reproductive rate and preadult survival were on their own insufficient to reverse the declines predicted from unmanipulated parameters, although the effect of persecution on preadult survival may be more severe than we estimated. In the absence of persecution we conclude that the population could expand to fill currently vacant but apparently suitable habitat and have a more secure long-term status.

Program MARK: Survival Estimation from Populations of Marked Animals

Article

Full-text available

Jan 1999
BIRD STUDY

MARK provides parameter estimates from marked animals when they are re-encountered at a later time as dead recoveries, or live recaptures or re-sightings. The time intervals between re-encounters do not have to be equal. More than one attribute group of animals can be modelled. The basic input to MARK is the encounter history for each animal. MARK can also estimate the size of closed populations. Parameters can be constrained to be the same across re-encounter occasions, or by age, or group, using the parameter index matrix. A set of common models for initial screening of data are provided. Time effects, group effects, time x group effects and a null model of none of the above, are provided for each parameter. Besides the logit function to link the design matrix to the parameters of the model, other link functions include the log—log, complimentary log—log, sine, log, and identity. The estimates of model parameters are computed via numerical maximum likelihood techniques. The number of parameters that are estimable in the model are determined numerically and used to compute the quasi-likelihood AIC value for the model. Both the input data, and outputs for various models that the user has built, are stored in the Results database which contains a complete description of the model building process. It is viewed and manipulated in a Results Browser window. Summaries available from this window include viewing and printing model output, deviance residuals from the model, likelihood ratio and analysis of deviance between models, and adjustments for over dispersion. Models can also be retrieved and modified to create additional models. These capabilities are implemented in a Microsoft Windows 95 interface. The online help system has been developed to provide all necessary program documentation.

Developing the Science of Reintroduction Biology

Article

Full-text available

Apr 2007

With recent increases in the numbers of species reintroduction projects and reintroduction-related publications, there is now a recognizable field of reintroduction biology. Nevertheless, research thus far has been fragmented and ad hoc, rather than an organized attempt to gain reliable knowledge to improve reintroduction success. We reviewed 454 recent (1990-2005) peer-reviewed papers dealing with wildlife reintroductions from 101 journals. Most research has been retrospective, either opportunistic evaluations of techniques or general project summaries, and most inference is gained from post hoc interpretation of monitoring results on a species-by-species basis. Documentation of reintroduction outcomes has improved, however, and the derivation of more general principles via meta-analyses is expected to increase. The fragmentation of the reintroduction literature remains an obstacle. There is scope to improve reintroduction biology by greater application of the hypothetico-deductive method, particularly through the use of modeling approaches and well-designed experiments. Examples of fruitful approaches in reintroduction research include experimental studies to improve outcomes from the release of captive-bred animals, use of simulation modeling to identify factors affecting the viability of reintroduced populations, and the application of spatially explicit models to plan for and evaluate reintroductions. We recommend that researchers contemplating future reintroductions carefully determine a priori the specific goals, overall ecological purpose, and inherent technical and biological limitations of a given reintroduction and that evaluation processes incorporate both experimental and modeling approaches. We suggest that the best progress will be made when multidisciplinary teams of resource managers and scientists work in close collaboration and when results from comparative analyses, experiments, and modeling are combined within and among studies.

Re-introduction and present status of the lynx ( Lynx Lynx ) in Switzerland

Article

Full-text available

Sep 1998
HYSTRIX

Abstract A lynx recovery programme started in Switzerland in 1970. From 1970-76, at least 14 lynx were translocated from the Carpathian Mountains into the Swiss Alps. Another re-introduction took place in the Jura Mountains, but no corridors exist as a connection between these two popula- tions in Switzerland. The development of the populations was not monitored at first. In 1980 systematic research was initiated, which gradually evolved into the Swiss Lynx Project. Not all releases were successful, but the re-introduction in the northern and western Alps founded a population that covered an area of some 4000 km² in 1981. In the western Swiss Alps, lynx moved into Italian and French territory. Towards the eastern Swiss Alps, the expansion was slower and ceased about ten years ago. During the last five years, there even has been a reduction of the area occupied. Today, the population covers an area of about 10000 km² in the Swiss Alps, of which 50% is suitable lynx habitat. Based on size and overlap of average home ranges of radio-tagged lynx, the population was estimated to include some 50 adult residents. At present, the growth rate of the population appears to be too low to allow a further expansion in range. It is uncertain whether recruitment is sufficient to compensate for the high losses among resident adults induced by traffic accidents and illegal killing.

A conservation framework for golden eagles: implications for their conservation and management in Scotland

Article

Full-text available

Full-text of this report is available at http://www.snh.org.uk/pdfs/publications/commissioned_reports/Report%20No193.pdf

Translocation as a Species Conservation Tool: Status and Strategy

Article

Full-text available

Sep 1989

Surveys of recent (1973 to 1986) intentional releases of native birds and mammals to the wild in Australia, Canada, Hawaii, New Zealand, and the United States were conducted to document current activities, identify factors associated with success, and suggest guidelines for enhancing future work. Nearly 700 translocations were conducted each year. Native game species constituted 90 percent of translocations and were more successful (86 percent) than were translocations of threatened, endangered, or sensitive species (46 percent). Knowledge of habitat quality, location of release area within the species range, number of animals released, program length, and reproductive traits allowed correct classification of 81 percent of observed translocations as successful or not.

The ecology and conservation of the Red Kite in Wales

Article

Jan 1973

Progam MARK: a gentle introduction

Book

Jan 2002

www.phidot.org/software/mark/docs/book

The Effects of Illegal Killing and Destruction of Nests by Humans on the Population Dynamics of the Hen Harrier Circus cyaneus in Scotland

Article

Aug 1997

1. Breeding productivity, natal dispersal and survival of hen harriers Circus cyaneus were studied between 1988 and 1995 on moorland managed for sport shooting of red grouse, other heather moorland and young conifer forests in the uplands of Scotland. 2. Nest success was much lower on grouse moors than on other land management classes. Annual productivity was 0-8 fledglings breeding female-1 year-1 on grouse moors compared with 2.4 on other moorland and 1-4 in young conifer forests. Human interference was recorded on half of the grouse moor estates studied and accounted for at least 30% of breeding failures in this land management class. It was much less frequent in the other land management classes. 3. Annual survival of female hen harriers which bred on grouse moors was about half that of females breeding on other moorland. On grouse moors, survival of females which bred unsuccessfully was much lower than that of females which reared at least one fledgling. Survival of breeding females on other moorland was high and unrelated to breeding success. The difference in survival of breeding females between grouse moors and other moors was attributed to killing by humans. On average, 55-74 females were killed each year, 11-15% of the total population of breeding females in Scotland, excluding Orkney. 4. The population of breeding females on grouse moors was estimated to decline rapidly without immigration. Harriers breeding on the other habitats were producing a surplus of female recruits approximately sufficient to compensate for the losses on grouse moors. 5. Most females started to breed at 1 year old and most males at 2 years old. The percentage of breeding males which were 1 year old was higher on grouse moors than on the other land management classes. 6. The median natal dispersal distance of both sexes exceeded 10 km. Harriers fledged from one land management class were often found breeding in another. 7. Natal dispersal resulted in net movements of 1-year-old females between land management classes which were sufficient to reduce the differences in population trend which would otherwise have occurred. Moorland managed for grouse shooting was a sink habitat which received two-thirds of its female recruits from other habitats. 8. The difference in productivity and survival between grouse moors and other habitats was attributed to illegal human interference. It is speculated that, without persecution, the hen harrier population in Scotland would increase, initially by about 13 % year-1, until a new, but unknown, equilibrium level was reached.

Distribution and Breeding of Red Kites Milvus milvus in Relation to Afforestation and Other Land-Use in Wales

Article

Apr 1996

1. Between 1946 and 1993, the numbers of territorial red kites, which form an isolated relict population in central Wales, increased from seven pairs to 113 pairs. 2. Throughout this period, concern has repeatedly been expressed that the afforestation of the Welsh uplands might affect kites adversely, by reducing the area of open foraging habitat. At present, only 16% of the total area used by kites in Wales is under trees. The several analyses performed here gave no firm indication that conifer afforestation up to current levels has had any detrimental effects on the distribution, numbers or breeding performance of kites. 3. Within the local landscape, kites preferred areas rich in native oaks and other broad-leaved trees in which to nest. Such remnants of woodland emerged as the main features influencing their distribution within the current range. 4. Within the range of local densities found in Wales (1-13 pairs per 5-km square), kites bred no worse, and no better, at high density than at low density.

Sources of variation in mortality of the Bearded Vulture Gypaetus barbatus in Europe

Article

Mar 2008
BIRD CONSERV INT

We analyse the causes of mortality for the Bearded Vulture in Europe. Shooting (31%), intentional poisoning (26%), collision (18%) and unintentional poisoning (12%) were the most important causes of mortality. No differences were found between sexes or age classes (non-adults and adults) for any of the causes of death. When the four main categories of mortality were grouped in periods of 3 years from 1986 (coinciding with the species' reintroduction to the Alps) to 2006, mortality showed significant temporal variation. The results suggest that while the number of collision/electrocution deaths has remained stable or increased slightly, the number of cases of shooting has declined during the last 6 years, while at the same time intentional and unintentional poisonings have increased. We found substantial differences between causes of mortality recorded for birds located by chance (75% related to shootings and collisions with powerlines) and radio-tagged birds (86% related to intentional and unintentional poisoning), suggesting biases in methodology for monitoring mortality. The results suggest that human persecution continues to be the main factor contributing to unnatural mortality for European Bearded Vultures. Future management actions should concentrate on the creation of protocols for the collection of carcasses and detailed analyses to determine and mitigate anthropogenic sources of mortality.

Birds in Europe: Population Estimates, Trends and Conservation Status

Article

Jul 2006

Bruce Peterjohn

The following critiques express the opinions of the individual evaluators regarding the strengths, weaknesses, and value of the books they review. As such, the appraisals are subjective assessments and do not necessarily reflect the opinions of the editors or any official policy of the American Ornithologists' Union.

Evaluating the success of translocating Red Kites Milvus milvus to the UK

Article

Jul 1999
BIRD STUDY

In an attempt to extend the breeding range of the Red Kite within the United Kingdom, 93 (48 males and 45 females) juvenile Red Kites, originating from Spain, Sweden and Wales, were released in southern England in 1989–94, and 93 (52 males, 40 females and one unsexed) juvenile Red Kites, originating from Sweden, were released in northern Scotland in 1989–93. Minimum estimates for first-year survival were 83.1% and 78.0% for male and female Red Kites in England, and 50.0% and 52.5% in Scotland, respectively. Annual survival then improved in the second and third years. Several sick or injured birds were recaptured, treated and returned to the wild, and some of these eventually bred. In their first year, birds released in Scotland tended to disperse greater distances than those released in England, females travelled further than males, and birds released during the early years dispersed further than those released during the later years. Successful breeding started in 1992 in England and Scotland. The mean age of first breeding was 1.9 years and 2.6 years for males and 1.8 years and 1.7 years for females in England and Scotland, respectively. There was a minimum of 59 clutches laid in England and 29 in Scotland in 1991–95. Clutch size averaged 2.9 (England) and 3.0 (Scotland), fledged brood size per breeding pair was 1.9 (England) and 1.6 (Scotland), and fledged brood size per successful pair was 2.3 (England) and 2.2 (Scotland). Demographic parameters were used to construct deterministic models for population growth. At current rates of growth, it is predicted that the English and Scottish populations will exceed 100 breeding pairs by 1998 and 2007, respectively.

Large Predators in the Alps: The Fall and Rise of Man’s Competitors. Biological Conservation 83: 279-289

Article

Mar 1998
BIOL CONSERV

Urs Breitenmoser

The brown bear Ursus arctos, wolf Canis lupus, and Eurasian lynx Lynx lynx vanished during the 18th and 19th centuries from all regions of high human activity in Europe because of direct persecution and environmental changes. Bear, wolf, and lynx were vulnerable in different ways to deforestation and the destruction of wild ungulate populations. Analysing the ecological factors responsible for the fall of the large carnivores can help to prepare their recovery. The return of large predators into semi-natural areas such as the Alps is possible, as the forests have expanded, and the wild ungulate populations increased. Lynx reintroduction in the Alps started in the 1970s. Wolves returned to the south-western Alps from the central Italian population in the early 1990s. The brown bear is recolonising the Austrian Alps from Slovenia. However, the modern protective legislation is not backed by a cooperative attitude among the affected people. In rural areas, large carnivores are still regarded as unrestrained killers of wildlife and livestock. Ecological conditions and husbandry in the Alps have been altered substantially since the large carnivores were eradicated, and the potential for conflicts has diminished. But stockmen have lost any remaining tradition of coexistence with large predators, and sheep are again very abundant in the Swiss Alps. The return of the large predators will not be possible without changing the system of sheep-husbandry. The rural people are not yet willing to do so. They generally object to any change in their lifestyle induced from outside, and the large predators become a negative symbol for restrictive conservation measures considered to hinder economic development. Nature conservation, including the reintegration of large predators, must be integrated into rural development; local people must be much more involved in this process.

Population Limitation In Birds

Article

Jan 1998

Ian Newton

Single-Locus Profiling Reveals Loss of Variation in Inbred Populations of the Red Kite (Milvus milvus)

Article

Mar 1993
Proc Biol Sci

Illegal killing slows population recovery of a re-introduced raptor of high conservation concern – the Red Kite Milvus milvus

Abstract

No full-text available