Individual heterogeneity in resource selection has implications for mortality risk in white‐tailed deer

Influence of natal habitat preference on habitat selection during extra-home range movements in a large ungulate

Natal habitat preference induction (NHPI) occurs when animals exhibit a preference for new habitat that is similar to that which they experienced in their natal environment, potentially leading to post-dispersal success. While the study of NHPI is typically focused on post-settlement home ranges, we investigated how this behavior may manifest during extra-home range movements (EHRMs), both to identify exploratory prospecting behavior and assess how natal habitat cues may influence path selection before settlement. We analyzed GPS collar relocation data collected during 79 EHRMs made by 34 juvenile and subadult white-tailed deer (Odocoileus virginianus) across an agricultural landscape with highly fragmented forests in Illinois, USA. We developed a workflow to measure multidimensional natal habitat dissimilarity for each EHRM relocation and fit step-selection functions to evaluate whether natal habitat similarity explained habitat selection along movement paths. Across seasons, selection for natal habitat similarity was generally weak during excursive movements, but strong during dispersals, indicating that NHPI is manifested in dispersal habitat selection in this study system and bolstering the hypothesis that excursive movements differ functionally from dispersal. Our approach for extending the NHPI hypothesis to behavior during EHRMs can be applied to a variety of taxa and can expand our understanding of how individual behavioral variation and early life experience may shape connectivity and resistance across landscapes.

Extrinsic traits consistently drive microhabitat decisions of an arboreal snake, independently of sex and personality

One pivotal topic on habitat selection is to understand the influence of intrinsic and extrinsic factors on the selection process. Although the effect of some extrinsic variables and sex has been extensively studied, almost nothing is known about the effect of personality, particularly on snakes. Here we addressed the relative importance of extrinsic (tree-related) and intrinsic (sex and personality) factors driving microhabitat selection decisions of a nocturnal tree snake (Leptodeira annulata). We implemented a protocol to quantify the influence of personality and sex on the role of extrinsic variables on microhabitat selection. First, we conducted three behavioral experiments to extract the shyness-boldness and avoidance-exploitation personality traits of male snakes. Then, we evaluated the role of sex and personality on the effect of tree-traits (thickness, canopy cover and shelter availability) on microhabitat selection, using two-step conditional logistic regression. Snakes consistently selected tree trunks, preferably thick and with high canopy cover and shelter availability, independently of their sex of personality. For this species, only extrinsic variables determined microhabitat decisions. Our protocol will aid to quantify the role of personality on microhabitat selection of other species and understand whether this is an important variable in habitat decision-making or not.

Individual variability in space use near power lines by a long‐lived territorial raptor

Evaluating species responses to anthropogenic infrastructures and other habitat changes is often used to assess environmental impacts and to guide conservation actions. However, such studies are generally carried out at the population level, disregarding inter‐individual variability. Here, we investigate population‐ and individual‐level responses toward power lines of a territorial raptor, the Bonelli's eagle Aquila fasciata. We used GPS‐PTT tracking data of 17 adult eagles to model space use as a function of distance to transmission and distribution lines, while accounting for other habitat features known to affect this species. At population level, eagles increased the intensity of space use in the proximity of power lines (up to 1,000 m), suggesting an attraction effect. At individual level, some eagles shared the general population attraction pattern, while others showed reduced intensity of space use in the proximity of power lines. These differential responses were unrelated to the sex of individuals, but were affected by the characteristics of the power grid, with a tendency for apparent attraction to be associated with individuals occupying home ranges with a denser network of transmission lines and transmission pylons. However, the study could not rule out the operation of other potentially influential factors, such as individual idiosyncrasies, the spatial distribution of prey availability, and the availability of natural perches and nesting sites. Overall, these results suggest that power lines may drive different behaviors and have differential impacts across individuals, with those attracted to the proximity of power lines potentially facing increased risk of mortality through electrocution and collision, and those avoiding power lines being potentially subject to exclusion effects. More generally, our results reinforce the need to understand individual variability when assessing and mitigating impacts of anthropogenic infrastructures.