Jennifer A Gill

Jennifer A Gill
University of East Anglia | UEA · School of Biological Sciences

About

144
Publications
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10,134
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Publications

Publications (144)
Article
Full-text available
In migratory systems, variation in individual phenology can arise through differences in individual migratory behaviors, and this may be particularly apparent in partial migrant systems, where migrant and resident individuals are present within the same population. Links between breeding phenology and migratory behavior or success are generally inv...
Article
Planting forests is a commonly suggested measure to mitigate climate change. The resulting changes in habitat structure can greatly influence the diversity and abundance of pre‐existing wildlife. Understanding these consequences is key for avoiding unintended impacts of afforestation on habitats and populations of conservation concern. Afforestatio...
Article
Yearly electricity production has increased steadily in the world in recent decades and the associated overhead power lines are widespread and occur across urban and natural habitats, and often in remote areas where there is little other anthropogenic influence. Here we assessed the effects of overhead power lines on the density of ground‐nesting b...
Article
Full-text available
Changes in phenology and distribution are being widely reported for many migratory species in response to shifting environmental conditions. Understanding these changes and the situations in which they occur can be aided by understanding consistent individual differences in phenology and distribution and the situations in which consistency varies i...
Article
Full-text available
The dynamics of wild populations are governed by demographic rates which vary spatially and/or temporally in response to environmental conditions. Conservation actions for widespread but declining populations could potentially exploit this variation to target locations (or years) in which rates are low, but only if consistent spatial or temporal va...
Article
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Background: In migratory species, the extent of within- and between-individual variation in migratory strategies can influence potential rates and directions of responses to environmental changes. Quantifying this variation requires tracking of many individuals on repeated migratory journeys. At temperate and higher latitudes, low levels of within-...
Article
Full-text available
Capsule Early male arrival on the breeding grounds results in early pairing but not early nesting in Chiffchaffs Phylloscopus collybita, and Chiffchaffs can nest, fail, and re-nest before Willow Warblers Phylloscopus trochilus begin nesting. Aims To quantify the consequences of timing of arrival for the subsequent timing of pairing, nesting, and r...
Article
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1. To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence-based decisions and of the value of evidence synthesis. 2. If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an...
Article
We estimated the influence of human disturbance and environmental factors on territory establishment in common ringed plovers Charadrius hiaticula and Eurasian oystercatchers Haematopus ostralegus, to inform the conservation of these species. We examined a 212 km stretch of coastline in the United Kingdom in 2003, mapping all breeding pairs of both...
Article
Wildlife conservation policies directed at common and widespread, but declining, species are difficult to design and implement effectively, as multiple environmental changes are likely to contribute to population declines. Conservation actions ultimately aim to influence demographic rates, but targeting actions towards feasible improvements in thes...
Article
Full-text available
1. To be effective, the next generation of conservation practitioners and managers need to be critical thinkers with a deep understanding of how to make evidence‐based decisions and of the value of evidence synthesis. 2. If, as educators, we do not make these priorities a core part of what we teach, we are failing to prepare our students to make an...
Chapter
Caribbean reefs have experienced unprecedented changes in the past four decades. Of great concern is the perceived widespread shift from coral to macroalgal dominance and the question of whether it represents a new, stable equilibrium for coral-reef communities. The primary causes of the shift—grazing pressure (top-down), nutrient loading (bottom-u...
Article
Migratory behavior can differ markedly amongst individuals within populations or species. Understanding the factors influencing this variation is key to understanding how current environmental changes might influence migratory propensity and the distribution and abundance of migratory species across their range. Here, we investigate variation in mi...
Article
Full-text available
Ground‐nesting species are vulnerable to a wide range of predators, and often experience very high levels of nest predation. Strategies to reduce nest vulnerability can include concealing nests in vegetation and/or nesting in locations in which nests and eggs are camouflaged and less easy for predators to locate. These strategies could have importa...
Article
Full-text available
Impacts of generalist predators on declining prey populations are a major conservation issue, but management of this situation is constrained by limited knowledge of the factors influencing predator distribution and activity. In many declining populations of ground-nesting waders, high levels of nest and chick predation are preventing population re...
Article
Many migratory systems are changing rapidly in space and time, and these changes present challenges for conservation. Changes in local abundance and site occupancy across species' ranges have raised concerns over the efficacy of the existing protected area networks, while changes in phenology can potentially create mismatches in the timing of annua...
Article
Full-text available
In migratory birds, early arrival on breeding sites is typically associated with greater breeding success, but the mechanisms driving these benefits are rarely known. One mechanism through which greater breeding success among early arrivers can potentially be achieved is the increased time available for replacement clutches following nest loss. How...
Preprint
Full-text available
Caribbean reefs have experienced unprecedented changes in the past four decades. Of great concern is the perceived widespread shift from coral to macroalgal dominance and the question of whether it represents a new, stable equilibrium for coral-reef communities. The primary causes of the shift -- grazing pressure (top-down), nutrient loading (botto...
Article
Full-text available
Phenological changes in response to climate change have been recorded in many taxa, but the population‐level consequences of these changes are largely unknown. If phenological change influences demography, it may underpin the changes in range size and distribution that have been associated with climate change in many species. Over the last century,...
Article
The capacity of different landscapes to sustain viable populations depends on the spatial and temporal availability of key population-specific resources. Heterogeneous landscapes provide a wider range of resources and often sustain higher levels of biodiversity than homogeneous ones. Across the globe, agricultural expansion has resulted in large-sc...
Article
Capsule: The first ever survey of Oystercatchers wintering in Iceland found around 11 000 individuals. This is an estimated 30% of the Icelandic population, including juveniles, suggesting that approximately 26 000 Icelandic Oystercatchers migrate to western Europe in the autumn. More Oystercatchers winter in Iceland than at similar latitudes elsew...
Article
Changes in demographic rates underpin changes in population size, and understanding demographic rates can greatly aid the design and development of strategies to maintain populations in the face of environmental changes. However, acquiring estimates of demographic parameters at relevant spatial scales is difficult. Measures of annual survival rates...
Article
Full-text available
Agriculture is one of the primary threats to biodiversity but agricultural land can also provide key resources for many species and, in some parts of the world, agricultural land supports important populations of species of conservation concern. In these cases, it is important to understand species' use of agricultural land before further expansion...
Article
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Population size changes can lead to changes in local abundance and/or site occupancy, depending on the processes influencing site use by individuals. Here, we quantify such changes for wintering waterbirds and assess their implications for widely used conservation strategies in which sites that support in excess of a given proportion of a populatio...
Article
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The Numeniini is a tribe of 13 wader species (Scolopacidae, Charadriiformes) of which seven are Near Threatened or globally threatened, including two Critically Endangered. To help inform conservation management and policy responses, we present the results of an expert assessment of the threats that members of this taxonomic group face across migra...
Article
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Intensified agricultural practices have driven biodiversity loss throughout the world, and although many actions aimed at halting and reversing these declines have been developed, their effectiveness depends greatly on the willingness of stakeholders to take part in conservation management. Knowledge of the willingness and capacity of landowners to...
Article
Capsule: Northern Lapwing Vanellus vanellus avoid nesting close to small woodland patches but nest predation rates do not vary with distance to woodland patches, either because risky areas are avoided or perceived nest predation risk does not reflect actual risk. Aims: To explore the effects of woodland patches in wet grassland landscapes on nest d...
Article
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Key demographic parameters often show substantial annual variation that can have important consequences for rates of population growth. Since 2011 we have conducted annual estimates of the productivity of Icelandic Black-tailed Godwits Limosa limosa islandica over a large part of their breeding range. During this period, a volcanic eruption resulte...
Article
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Wetland ecosystems throughout the world are threatened by drainage and intensification of agriculture. Consequently, many wetland species of conservation concern are now restricted to fewer and smaller sites, and maintaining these species often requires intensive habitat management. 2.In Western Europe, breeding wader populations have declined seve...
Data
Figure S1. The association between estimates of male and female recapture probability at the 34 CE sites (black line is the line of unity). Figure S2. Annual variation in the random effect of year included in models of adult annual survival of male (black circles) and female (open circles) willow warblers at CE sites. Appendix S1. jags code used...
Article
Full-text available
Male‐biased sex ratios occur in many bird species, particularly in those with small or declining populations, but the causes of these skews and their consequences for local population demography are rarely known. Within‐species variation in sex ratios can help to identify the demographic and behavioural processes associated with such biases. Small...
Article
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On page 516, in the second paragraph of the subsection (b) Half-asymptote constant, and for a reason that it has proved impossible to discover, there is a significant error. The equation: log e half-asymptote constant = −24 77 + 6.307log e body mass + 5.030log e prey mass + 10.594 dummy variable oystercatcher = 1 is completely wrong and, instead, w...
Article
In Europe, lowland wet grasslands have become increasingly fragmented, and populations of waders in these fragments are subject to unsustainably high levels of nest predation. Patches of taller vegetation in these landscapes can support small mammals, which are the main source of prey for many predators. Providing such patches of habitat could pote...
Data
Association between bird abundance and climate variables.
Article
Full-text available
Across the globe, deserts and volcanic eruptions produce large volumes of atmospheric dust, and the amount of dust is predicted to increase with global warming. The effects of long-distance airborne dust inputs on ecosystem productivity are potentially far-reaching but have primarily been measured in soil and plants. Airborne dust could also drive...
Article
Individual specialization in resource use is a widespread driver for intra-population trait variation, playing a crucial evolutionary role in free-living animals. We investigated the individual foraging specialization of Black-tailed Godwits (Limosa limosa islandica) during the wintering period. Godwits displayed distinct degrees of individual spec...
Article
Full-text available
Recent advances in spring arrival dates have been reported in many migratory species but the mechanism driving these advances is unknown. As population declines are most widely reported in species that are not advancing migration, there is an urgent need to identify the mechanisms facilitating and constraining these advances. Individual plasticity...
Article
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Aim: Recent, rapid population declines in many Afro-Palaearctic migratory bird species have focussed attention on changing conditions within Africa. However, processes influencing population change can operate throughout the annual cycle and throughout migratory ranges. Here, we explore the evidence for impacts of breeding and non-breeding conditio...
Article
Full-text available
Capsule Recent annual productivity of Arctic Terns Sterna paradisaea in Iceland has been persistently low, primarily because of very low rates of chick fledging. Aims To quantify current levels of productivity in Arctic Terns in Iceland, and the extent to which this varies among 10 colonies across the Snaefellsnes peninsula, West Iceland. Methods B...
Article
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We investigate conflicts between wildlife conservation and recreational use that can occur at open-access sites when visitors dislike crowding. A theoretical model is proposed which determines the spatial distributions of visitors to a beach, given their willingness to walk to avoid crowding and the configuration of beach access points. This model...
Article
Full-text available
Effects of local weather on individuals and populations are key drivers of wildlife responses to climatic changes. However, studies often do not last long enough to identify weather conditions that influence demographic processes, or to capture rare but extreme weather events at appropriate scales. In Iceland, farmers collect nest down of wild comm...
Data
(map) Numbers indicate locations of 17 colonies in Iceland which provided breeding numbers of common eider (Somateria mollissima) used in this study; numbers refer to numbers of colonies in Table 1. Names are the weather stations considered in this study. (TIF)
Data
Principal components analysis of weather data from Stykkishólmur, West Iceland, for different periods where eider nests were counted in Iceland. The first two principal scores (PC) were used as indices of local weather. The highest loading for each variable in each analysis is indicated in bold. (DOC)
Article
Full-text available
Resolving the migratory connectivity (identifying non-breeding grounds) of migrating bird populations that are morphologically similar is crucial for an understanding of their population dynamics and ultimately their conservation. Such is the case in Black-tailed Godwits Limosa limosa, where the Iceland-breeding subspecies islandica shows overlap d...
Article
Capsule Stable isotope composition of feathers grown in Africa indicates that Willow Warblers, Phylloscopus trochilus, breeding in areas of Britain experiencing different population trends may vary in their distribution, timing of moult and/or use of prey resources during the non-breeding season. Aims To compare stable isotope ratios of feathers of...
Article
The relative fitness of individuals across a population can shape distributions and drive population growth rates. Migratory species often winter over large geographic ranges, and individuals in different locations experience very different environmental conditions, including different migration costs, which can potentially create fitness inequalit...
Article
Full-text available
In migratory species, sexual size dimorphism can mean differing energetic requirements for males and females. Differences in the costs of migration and in the environmental conditions occurring throughout the range may therefore result in sex-biases in distribution and resource use at different spatial scales. In order to identify the scale at whic...
Data
The study explored fitness inequalities of energetic trade-offs on Icelandic Black-tailed Godwits wintering across the range. The conditions experienced by Icelandic Godwits (Limosa limosa islandica) at wintering locations throughout their range vary greatly, with important consequences for individual fitness. The costs of thermoregulation and low...
Article
Full-text available
There is increasing concern over the consequences of environmental change for people and communities that depend on already fragile marine resources, given the mounting evidence of sustained over-exploitation and climate change impacts on marine systems. In order to explore the potential social resilience of marine-dependent livelihoods to environm...
Article
We review the conservation issues facing migratory shorebird populations that breed in temperate regions and use wetlands in the non-breeding season. Shorebirds are excellent model organisms for understanding ecological, behavioural and evolutionary processes and are often used as indicators of wetland health. A global team of experienced shorebird...
Article
Full-text available
Climate change could have major implications for the global tourism industry if changing environmental conditions alter the attractiveness of holiday destinations. Countries with economies dependent on tourism and with tourism industries reliant on vulnerable natural resources are likely to be particularly at risk. We investigate the implications t...
Article
Full-text available
Several expressions of sexual segregation have been described in animals, especially in those exhibiting conspicuous dimorphism. Outside the breeding season, segregation has been mostly attributed to size or age-mediated dominance or to trophic niche divergence. Regardless of the recognized implications for population dynamics, the ecological cause...
Data
Generalized linear mixed models relating dietary composition of black-tailed godwits to prey density (including invertebrate density data from 2007), culmen length, sex and date. Dietary composition is expressed as proportion of each prey type consumed in biomass. The table presents comparisons of increasingly simpler nested models, using likelihoo...