Body size is implicated in individual fitness and population dynamics. Mounting interest is being given to the effects of environmental change on body size, but the underlying mechanisms are poorly ...understood. We tested whether body size and body condition are related to ambient temperature (heat maintenance hypothesis), or/and explained by variations in primary production (food availability hypothesis) during the period of body growth in songbirds. We also explored whether annual population‐level variations of mean body size are due to changes of juvenile growth and/or size‐dependent mortality during the first year. For 41 species, from 257 sites across France, we tested for relationships between wing length (n = 107 193) or body condition (n = 82 022) and local anomalies in temperature, precipitation and net primary production (NDVI) during the breeding period, for juveniles and adults separately. Juvenile body size was best explained by primary production: wings were longer in years with locally high NDVI, but not shorter in years with low NDVI. Temperature showed a slightly positive effect. Body condition and adult wing length did not covary with any of the other tested variables. We found no evidence of climate‐driven size‐dependent mortality for the breeding season. In our temperate system, local climatic anomalies explained little of the body size variation. A large part of wing length variance was site‐specific, suggesting that avian size was more dependent on local drivers than global ones. Net primary production influenced juvenile size the most through effects on body growth. We suggest that, during the breeding season in temperate systems, thermoregulatory mechanisms are less involved in juvenile growth than food assimilation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Background
The European Kingfisher (
Alcedo atthis
) is a small plunge-diving bird, today considered a species of conservation concern in Europe given its rapid population decline observed ...across the continent. We implemented a pilot study aimed at providing first data allowing to: (1) assess home range features of the European Kingfisher for populations with unevenly distributed feeding habitats; (2) define conservation implications for habitats exploited by such populations; and (3) evaluate possibilities for developing GPS tracking schemes dedicated to home range studies for this species that could be possibly applied to other small plunge-diving birds.
Methods
In 2018 and 2019, we equipped 16 breeding European Kingfishers sampled within the marshes of the Gironde Estuary (France), with miniaturized and waterproof GPS archival tags deployed with leg-loop harnesses (total equipment mass = 1.4 g; average bird mass = 40.18 ± 1.12 g).
Results
On average, we collected 35.31 ± 6.66 locations usable for analyses, without a significant effect on bird body condition (
n
= 13 tags retrieved). Data analyses highlighted rather limited home ranges exploited by birds (average = 2.50 ± 0.55 ha), composed on average by 2.78 ± 0.40 location nuclei. Our results also underscore: (1) a rather important home range fragmentation index (0.36 ± 0.08); and (2) the use by birds of different types of small wetlands (wet ditches, small ponds or small waterholes), often exploited in addition to habitats encompassing nest locations.
Conclusions
Our study reveals interesting GPS tracking possibilities for small plunge-diving birds such as the European Kingfisher. For this species, today classified as vulnerable in Europe, our results underline the importance of developing conservation and ecological restoration policies for wetland networks that would integrate small wetlands particularly sensitive to global change.
How the spatial expansion of a species changes at a human time scale is a process difficult to determine. We studied the dispersal pattern of the French white stork population, using a 21-year ...ringing/resighting dataset. We used the graph-theory to investigate the strength of links between 5 populations (North-East, North-West, Centre, West, and South) and to determine factors important for the birds' movements. Two clusters of populations were identified within the metapopulation, with most frequent movements of individuals between North-Eastern and Centre populations, and between North-Western and Western populations. Exchanges of individuals between populations were asymmetrical, where North-Eastern and North-Western populations provided more emigrants than they received immigrants. Neither the geographical distance between populations, nor the difference in densities influenced the number of individuals exchanging between populations. The graph-theory approach provides a dynamic view of individual movements within a metapopulation and might be useful for future population studies in the context of conservation.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract Synchronous variation in demographic parameters across species increases the risk of simultaneous local extinction, which lowers the probability of subsequent recolonization. Synchrony ...therefore tends to destabilize meta‐populations and meta‐communities. Quantifying interspecific synchrony in demographic parameters, like abundance, survival, or reproduction, is thus a way to indirectly assess the stability of meta‐populations and meta‐communities. Moreover, it is particularly informative to identify environmental drivers of interspecific synchrony because those drivers are important across species. Using a Bayesian hierarchical multisite multispecies mark–recapture model, we investigated temporal interspecific synchrony in annual adult apparent survival for 16 common songbird species across France for the period 2001–2016. Annual adult survival was largely synchronous among species (73%, 95% credible interval 47%–94% of the variation among years was common to all species), despite species differing in ecological niche and life history. This result was robust to different model formulations, uneven species sample sizes, and removing the long‐term trend in survival. Synchrony was also shared across migratory strategies, which suggests that environmental forcing during the 4‐month temperate breeding season has a large‐scale, interspecific impact on songbird survival. However, the strong interspecific synchrony was not easily explained by a set of candidate weather variables we defined a priori. Spring weather variables explained only 1.4% 0.01%–5.5% of synchrony, while the contribution of large‐scale winter weather indices may have been stronger but uncertain, accounting for 12% 0.3%–37% of synchrony. Future research could jointly model interspecific variation and covariation in breeding success, age‐dependent survival, and age‐dependent dispersal to understand when interspecific synchrony in abundance emerges and destabilizes meta‐communities.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Synchronous variation in demographic parameters across species increases the risk of simultaneous local extinction, which lowers the probability of subsequent recolonization. Synchrony therefore ...tends to destabilize meta‐populations and meta‐communities. Quantifying interspecific synchrony in demographic parameters, like abundance, survival, or reproduction, is thus a way to indirectly assess the stability of meta‐populations and meta‐communities. Moreover, it is particularly informative to identify environmental drivers of interspecific synchrony because those drivers are important across species. Using a Bayesian hierarchical multisite multispecies mark–recapture model, we investigated temporal interspecific synchrony in annual adult apparent survival for 16 common songbird species across France for the period 2001–2016. Annual adult survival was largely synchronous among species (73%, 95% credible interval 47%–94% of the variation among years was common to all species), despite species differing in ecological niche and life history. This result was robust to different model formulations, uneven species sample sizes, and removing the long‐term trend in survival. Synchrony was also shared across migratory strategies, which suggests that environmental forcing during the 4‐month temperate breeding season has a large‐scale, interspecific impact on songbird survival. However, the strong interspecific synchrony was not easily explained by a set of candidate weather variables we defined a priori. Spring weather variables explained only 1.4% 0.01%–5.5% of synchrony, while the contribution of large‐scale winter weather indices may have been stronger but uncertain, accounting for 12% 0.3%–37% of synchrony. Future research could jointly model interspecific variation and covariation in breeding success, age‐dependent survival, and age‐dependent dispersal to understand when interspecific synchrony in abundance emerges and destabilizes meta‐communities.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Phenological adjustment is the first line of adaptive response of vertebrates when seasonality is disrupted by climate change. The prevailing response is to reproduce earlier in warmer springs, but ...habitat changes, such as forest degradation, are expected to affect phenological plasticity, for example, due to loss of reliability of environmental cues used by organisms to time reproduction.
Relying on a two‐decade, country‐level capture‐based monitoring of common songbirds' reproduction, we investigated how habitat anthropization, here characterized by the rural–urban and forest–farmland gradients, affected the average phenology and plasticity to local temperature in two common species, the great tit Parus major and the blue tit Cyanistes caeruleus.
We built a hierarchical model that simultaneously estimated fledging phenology and its response to spring temperatures based on the changes in the proportion of juveniles captured over the breeding season.
Both species fledge earlier in warmer sites (blue tit: 2.94 days/°C, great tit: 3.83 days/°C), in warmer springs (blue tit: 2.49 days/°C, great tit: 2.75 days/°C) and in most urbanized habitats (4 days for blue tit and 2 days for great tit). The slope of the reaction norm of fledging phenology to spring temperature varied across sites in both species, but this variation was explained by habitat anthropization only in the deciduous forest specialist, the blue tit. In this species, the responses to spring temperature were shallower in agricultural landscapes and slightly steeper in more urban areas. Habitat anthropization did not explain variation in the slope of the reaction norm in the habitat‐generalist species (great tit), for which mean fledgling phenology and plasticity were correlated (i.e., steeper response in later sites).
The effects of habitat change on phenological reaction norms provide another way through which combined environmental degradations may threaten populations' persistence, to an extent depending on species and on the changes in their prey phenology and abundance.
In this study, we developed a method that enables the estimation of phenological reactions to local temperatures using Constant Effort Site bird ringing data. Our findings suggest that habitat anthropization explains variation in phenological plasticity but only for the most specialist species (blue tit).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
There is mounting evidence that climate warming can induce morphological changes locally, particularly size reduction. However, the direction of thermal stress may differ between climatic regions. We ...predicted that morphological response to temperature fluctuations should vary throughout species ranges, depending on the local climate. Hot temperature anomalies are expected to induce size reduction in hot regions where species live close to their upper thermal limit, whereas size stasis (or increase) would be expected in cold regions, where species live close to their lower thermal limit.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Aim
There is mounting evidence that climate warming can induce morphological changes locally, particularly size reduction. However, the direction of thermal stress may differ between climatic ...regions. We predicted that morphological response to temperature fluctuations should vary throughout species ranges, depending on the local climate. Hot temperature anomalies are expected to induce size reduction in hot regions where species live close to their upper thermal limit, whereas size stasis (or increase) would be expected in cold regions, where species live close to their lower thermal limit.
Location
France (204 sites).
Time period
2000–2014 springs.
Major taxa studied
Songbird species (n = 9).
Methods
We tested whether the effect of temperature anomalies on juvenile body size varied along an 11 °C thermal gradient.
Results
In warmer springs, juveniles were larger overall at the coldest sites, but this effect decreased toward the hottest sites, becoming negative for two species.
Main conclusions
Warming should induce body size increases more frequently at the cold edge of species distribution ranges, and rather body size declines at the hot edg. The climate dependency of the effect of weather fluctuations on body size is still under‐acknowledged, and the pattern identified deserves to be investigated over broader climatic gradients and taxonomic coverage. Climate‐driven changes in body size are therefore not uniform across climatic regions and within species ranges.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Among the 10,000 birds species living on earth, 5% (e.g., 560) need imperatively freshwater habitat in order to satisfy at least one of their life history traits. About 11 completed families could ...even disappear if their wetland habitat left. About 10% (58) of these can be considered as endemic. Africa contains the biggest number of endemic (20) and more precisely Madagascar. Among freshwater species, ducks and geese have a major importance in human activities in northern hemisphere related to food resources (hunting) or birding.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The identification of the characteristics of species that make them susceptible or resilient to climate change has been elusive because non-climatic influences may dominate short- and medium-term ...changes in population and distribution sizes. Here we studied the 2003 French heat wave, during which other confounding variables remained essentially unchanged, with a correlational approach. We tested the relationship between population resilience and thermal range by analysing the responses of 71 bird species to a 6-month heat wave. Species with small thermal ranges showed the sharpest decreases in population growth rate between 2003 and 2004 in locations with the highest temperature anomalies. Thermal range explained the resilience of birds to the heat wave independently of other potential predictors, although it correlated with nest location and broad habitat type used by species. The geographically deduced thermal range appears to be a reliable predictor of the resilience of these endothermic species to extreme temperatures.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK