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Behavioral adjustments are of critical importance for the survival of animals when exposed to risk and resource variations in their environment. Moving to safer habitats allows prey to reduce the risk of mortality triggered by predation. This response has been well studied at the population level to assist in identifying key habitat components for wildlife conservation. However, while individuals may differ in their response to risk and thus in their survival expectancy, the determinants of individual adjustments in space and habitat use are largely unknown in management and conservation studies. Using GPS monitoring, we investigated the relationship between individual traits (morphometry, personality, health status) and adjustments in the use of space relative to risky features (hedgerows, roads/tracks, woodlands, built-up areas) with regard to predation risk. We used the gray partridge (Perdix perdix) as a study model (captive-reared birds released into the farmlands). During the diel cycle, predation risk mainly occurs by carnivores at night, whereas human hunting pressure occurs during the day. We found that personality and health status had an effect on adjustments in the use of space as response to risky features. At night, when carnivore activity is expected to be high, bolder individuals were farther from hedgerows relative to the day. Similarly, individuals in good health were located farther from hedgerows, roads/tracks, and woodland at night relative to the day. We discuss the need for better consideration of individual traits in management and conservation programs, with a particular focus on recovery programs that rely on translocation of captive-reared individuals. [ABSTRACT FROM AUTHOR]

Interspecific competition is expected to occur between phylogenetically closely related species when sharing resources. In birds, interspecific competition often occurs by song-mediated interference and frequently implies asymmetrical outcomes between the species pairs involved. Habitat loss resulting from agricultural intensification is expected to have aggregated bird species in the remaining suitable habitats, thus increasing the likelihood of interspecific competition. However, this process has rarely been considered as a potential factor limiting population recovery in farmland birds. We investigated whether interspecific competition occurs between grey, Perdix perdix , and red-legged, Alectoris rufa , partridges, two phylogenetically related species. Originally parapatric, they have suffered an artificial increase in their contact zone due to huge human-mediated gamebird releases. We analysed territorial behaviour through a playback stimuli experiment and investigated shifts in habitat niche in the absence and presence of a hypothetical competitor. Results showed that the grey partridge appeared less territorial when co-occurring with the red-legged partridge and shifted its habitat niche away from the latter, while no such change was detected for the red-legged partridge. These asymmetrical patterns in behaviour and ecology are predicted under an interspecific competition scenario beneficial to the red-legged partridge, and therefore suggest that they are competitively dominant to grey partridges where they co-occur. This result has potentially strong implications for the management of grey partridges as gamebirds, and for their conservation in areas where they are almost extirpated. [ABSTRACT FROM AUTHOR]

Changes in agricultural practices have reshaped agricultural landscapes and triggered a drastic decline in spatial and temporal heterogeneity leading to changes in habitat quality and food resources for birds. However, the precise relationships between landscape changes, spatial and temporal heterogeneity, and habitat preferences in response to those changes remain poorly known.We investigated patterns of habitat selection and causes for changes over the years 1997–2017 for the gray partridge Perdix perdix, an iconic farmland species which has experienced a severe decline since the 1950s. Using a long‐term (1997–2017) dataset collected over 435 km2, we modeled relationships between annual land‐cover maps and partridge sightings over 17 5‐year moving windows, assessing the effects of landscape metrics, the strength of the relationships, and the dynamics of habitat suitability.We detected a shift in gray partridge habitat preferences over time, toward more risky habitats. Avoidance of predator reservoirs (woodlands and buildings) has weakened, and selection of human infrastructure, such as roads and tracks, has increased. Since 1997, the mean size of suitable patches has also decreased by about 26%.We have interpreted these changes in habitat selection as being the result of decreasing habitat quality and the increasing prevalence of captive‐reared birds, currently released in their thousands in the study site.Synthesis and applications. The gray partridge has not adjusted well to changes in farming practices, and the low, still decreasing, population density suggests that it is not sustainable, despite local initiatives and the investment in captive‐bird releases. We emphasize that efforts must be redirected toward habitat improvement to restore the density of refuge cover, insects, and seeds in the landscape, hunting management to ensure self‐sustainable populations and massive releases of high‐quality birds. Only integrated local management, involving hunters, farmers, gamekeepers, and scientists can ensure the recovery of this species. [ABSTRACT FROM AUTHOR]