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Following a steep decline, White Stork Ciconia ciconia populations in Germany are currently increasing, allowing us to examine potential density‐dependent effects on breeding dispersal. Our data suggest that the proportion of breeding dispersers has increased over time, indicating a density‐dependent component in nest‐site fidelity that may be linked to increased competition.
Few studies have quantified the dynamics of recovering populations of large raptors using long‐term, spatially explicit studies. Using data collected over 37 years in the western Italian Alps, we assessed the trends in distribution, abundance, fecundity and breeding population structure of Golden Eagles Aquila chrysaetos. Using the spatial distribution of territory centroids in 2007, we found that...
Between 2000 and 2009 we studied the diet and breeding success of Egyptian Vultures Neophron percnopterus in southern Spain. Wild species accounted for 74.9% of prey items (n = 1071) with a predominance of mammals (62.3%), followed by birds (20.8%) and reptiles (13.1%). Spatially, the diet was highly varied and not restricted to carcasses of livestock; wild Rabbits Oryctolagus cuniculus accounted...
Assessing variation in breeding performance in relation to habitat characteristics may provide insights into predicting the consequences of land‐use change on species ecology and population dynamics. We compared four Marsh Harrier Circus aeruginosus populations subject to similar environmental conditions, but which differed in habitat composition, ranging from natural habitats to intensively cultivated...
Long‐term studies can provide powerful insights into the relative importance of different demographic and environmental factors determining avian population dynamics. Here we use 23 years of capture–mark–recapture data (1981–2003) to estimate recruitment and survival rates for a Sand Martin Riparia riparia population in Cheshire, NW England. Inter‐annual variation in recruitment and adult survival...
The effect of changing climatic conditions on wild populations has been the subject of much recent research. Most attention has been on the direct effects of climate changes on species of lower trophic levels and on the negative consequences of climate change. However, a deeper understanding of how climate change affects apex predators is vital, as they are keystone species that have a disproportionate...
Reliable estimates of survival and dispersal are crucial to understanding population dynamics, but for seabirds, in which some individuals spend years away from land, mortality and emigration are often confounded. Multistate mark–recapture methods reduce bias by incorporating movement into the process of estimating survival. We used a multistate model to provide unbiased age‐specific survival and...
Factors affecting avian demography and abundance in urban landscapes are poorly understood and this hinders attempts to manage urban bird communities. Several recent studies indicate that lack of invertebrate prey in urban landscapes may constrain avian productivity and fitness relative to that in other habitats. House Sparrow Passer domesticus populations have undergone large declines in many European...
We report on an 11‐year study of floater interference in a population of Spanish Imperial Eagles Aquila adalberti. We analysed changes over the years in the productivity of 15 territories to test predictions of two hypotheses of density‐dependent productivity in relation to the presence of floaters (birds without territories). According to the ‘interference' hypothesis, the frequency of intrusion...
For migratory birds, it is necessary to estimate annual and overwinter survival rates, identify factors that influence survival, and assess whether survival varies with age and sex if we are to understand population dynamics and thus inform conservation. This study is one of the first to document overwinter and annual survival from the wintering grounds of a declining Afro‐Palaearctic migrant bird,...
In many taxa, environmental changes that alter resource availability and energetics, such as climate change and land use change, are associated with changes in body size. We use wing length as a proxy for overall structural body size to examine a paradoxical trend of declining wing length within a Yellowhammer Emberiza citrinella population sampled over 21 years, in which it has been previously shown...
Understanding the mechanisms that shape density‐dependent processes and population dynamics is often essential for species conservation. Two key mechanisms of density‐dependent reductions in reproductive performance are a limited access to foraging habitats (the habitat heterogeneity hypothesis) and territorial aggression towards conspecifics (the interference competition hypothesis) at high population...
Organochlorine pesticides disrupted reproduction and killed many raptorial birds, and contributed to population declines during the 1940s to 1970s. We sought to discern whether and to what extent territory occupancy and breeding success changed from the pesticide era to recent years in a resident population of Peregrine Falcons Falco peregrinus in southern Scotland using long‐term (1964–2015) field...
Mountain regions are globally important areas for biodiversity but are subject to multiple human‐induced threats, including climate change, which has been more severe at higher elevations. We reviewed evidence for impacts of climate change on Holarctic mountain bird populations in terms of physiology, phenology, trophic interactions, demography and observed and projected distribution shifts, including...
Agricultural intensification over the past decades has led to a generalized decline in farmland biodiversity. Farmland birds are particularly exposed to rapid changes in habitat and reduced food resources or availability. Understanding how farmland specialists can be preserved and their populations enhanced are major challenges for this century. Based on a long‐term (19‐year) study of a Eurasian Stone‐curlew...
Long‐distance migrants are particularly susceptible to climate change because of their multi‐stage life‐cycle, but understanding how climatic conditions at each of these stages influence population dynamics remains a key challenge. Here, we use long‐term data from a UK population of Sand Martins Riparia riparia, a declining Afro‐Palaearctic migrant, to investigate how weather on the wintering grounds...
Climate change is forecast to increase climatic variability, in particular the occurrence of extreme events. Consequently, it is imperative to understand how climatic variation influences the dynamics of communities. We investigated synchronicity in survival in response to climatic variation among bird communities occupying habitats that differed in climatic seasonality: a more seasonal wetland and...
Density‐dependence effects acting on fecundity can be explained by two competing hypotheses. The individual adjustment hypothesis (IAH) states that, as population density increases, interference among individuals negatively affects their breeding performance. The second hypothesis, the habitat heterogeneity hypothesis (HHH), proposes that, as more individuals occupy the space available, lower quality...
Rapid population declines of many long‐distance Afro‐Palaearctic migratory bird species are ongoing across Europe but the demographic drivers are often poorly understood, thereby limiting the development of appropriate conservation actions. Using long‐term population monitoring (39 years), capture–mark–recapture data and a matrix model, we estimated demographic parameters and the effect of climate...
European Turtle Doves Streptopelia turtur have experienced a sharp decline in population numbers over past decades. Much uncertainty exists about the main cause or causes. Several pressures have been suggested, but because they affect different stages of the life cycle of the Turtle Dove, it is difficult to compare their contributions to the population decline. Here we applied a full life cycle approach...
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