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Climate warming is driving species to shift their geographical distribution poleward to track suitable climatic conditions. Two strategies have been suggested to help species respond to climate warming: facilitating distribution change or improving persistence. We questioned whether habitat management in favour of duck hunting activities interacted with duck responses to climate warming. We studied nonbreeding waterbird community changes (110 species) over 28 years at 851 sites in South-West Europe, where habitat management is a common practice to attract and hunt ducks. We hypothesized that duck species targeted by habitat management do not need to track temperature changes as much as non-hunted species, because of the availability of suitable habitats provided by hunting land managers. We used the community temperature index (CTI) to assess the temporal responses of communities and species to climate warming. We compared the effect of hunting status with other functional traits on species responses, controlling for phylogenetic relatedness. The CTI trend has increased over the study period, indicating a community adjustment to climate warming. However, hunted ducks contributed to almost 40% of the negative contributions to this community adjustment, suggesting that hunted ducks do not shift their distribution as much as the other waterbirds do. Winter fidelity associated with the provision of attractive feeding grounds might explain why ducks did not seem to shift their distribution in response to climate warming. This study suggests the broad impact of human activities on wildlife, including on large-scale distribution processes, and questions the long-term consequences on duck populations. [ABSTRACT FROM AUTHOR]

Artificial light at night (ALAN) is considered as a major threat to biodiversity, especially to nocturnal species, as it reduces availability, quality and functionality of habitats. However, its effects on the way species use landscape elements such as rivers are still largely understudied, especially the effect of crossing infrastructure lighting on bridges. These elements are nevertheless key commuting and foraging habitats in heavily urbanised landscapes for several taxa such as bats that are particularly affected by ALAN. We studied the effects of the illumination of facades and undersides of bridges on the relative abundance of pipistrelle bats, on their 3D distribution and their behavioural response (i.e. flight speed) close to bridges. We set‐up an innovative approach based on a microphone‐array to reconstruct positions and flight trajectories in 3D. We studied the effect of lighting on bats in the close proximity of six similar bridges, mostly differentiated by the presence or absence of lighting (3 lit and 3 unlit). All bridges cross the same waterway, within a uniformly and highly urbanized agglomeration (Toulouse, France). We found that bat activity was 1.7 times lower in lit sites. Bats tended to keep a larger distance, and to fly faster close to illuminated bridges. These results suggest that bridge lighting strongly reduces habitat availability and likely connectivity for bats. In that case, results call for switching off the illumination of such bridges crossing riverine ecosystems to preserve their functionality as habitats and corridors for bats. [ABSTRACT FROM AUTHOR]

The effective conservation of aquatic warbler Acrocephalus paludicola, one of the most threatened western Palaearctic migratory passerines, requires good knowledge of its ecological needs at stopover sites. In particular, identifying its diet, which controls the accumulation of fat reserves during migration, facilitates the selection and management of adequately protected areas. Further key information includes the relationship between prey species abundance and habitats of aquatic warbler on stopover. We performed standardized mist netting in the Audierne marshes (western France) during 12 years, which resulted in the capture of 1200 aquatic warblers, and provided measurements for mass gain and the collection of faeces to infer the birds' diet. Invertebrate sampling was carried out in the three main Audierne marsh habitats (reed bed, fen mire and meadow). In order to go beyond prey digestibility bias, we also studied two closely related Acrocephalus species, present at migration stopover sites during the same period. We found that the diet composition of aquatic warbler observed at migration stopover sites is based on large-sized prey (Odonata, Orthoptera, Lepidoptera). Like sedge warblers, aquatic warblers put on weight during migration stopovers (daily mass gain=0.38 g). This increase in weight suggests that the aquatic warblers might have adopted a strategy for long-distance migration with few stopovers only. Owing to great differences in diet, conservation management for the threatened aquatic warbler at stopover sites should not rely on existing knowledge about sedge and reed warblers. Similarities in the diet of aquatic warbler between nesting areas and migration stopover areas and the relationship between habitat and prey abundance suggest that fen mires play an important role in the quality of the foraging habitat at stopover sites. [ABSTRACT FROM AUTHOR]