Under cover of the night: context-dependency of anthropogenic disturbance on stress levels of wild roe deer Capreolus capreolus

Abstract

Wildlife populations are increasingly exposed to human-induced modifications of their habitats. To cope with anthropogenic stressors, animals can adjust their behaviour—for example, by shifting their activity to more sheltered habitats, or becoming more nocturnal. However, whether use of spatial and temporal adjustments in behaviour may regulate the endocrine response is poorly documented. Here, we analyzed faecal cortisol metabolites (FCMs) of wild roe deer (Capreolus capreolus) living in a human-dominated agro-ecosystem. Using Global Positioning System monitoring of 116 individuals, we assessed their spatial behaviour and tested whether proximity to anthropogenic structures (linear distance to built-up areas) and the use of refuge habitats (woodland and hedges) influenced FCM levels. In accordance with our predictions, individuals ranging closer to anthropogenic structures during daytime had higher FCM levels, but this relationship was buffered as use of refuge habitat increased. In addition, this link between proximity to anthropogenic structures and FCM levels disappeared when we analyzed spatial behaviour at night. Finally, FCM levels were higher when the ambient temperature was lower, and during years of low resource availability. Our results demonstrate that the stress levels of large mammals may be strongly influenced by their proximity to anthropogenic activities, but that these effects may be buffered by behavioural adjustments in terms of space use and circadian rhythm. Whereas most studies have focused on the influence of environmental heterogeneity, our analysis highlights the need to also consider the fine-scale spatial response of individuals when studying the hormonal response of wild animals to human disturbance. We emphasize the potential to mitigate this hormonal stress response, and its potential negative consequences on population dynamics, through the preservation or restoration of patches of refuge habitat in close proximity to human infrastructure.

Short-term telomere dynamics is associated with glucocorticoid levels in wild populations of roe deer

“…Once this individual was removed, individual concentrations of FGMs in 2016 and 2017 were no longer correlated (r = 0.18, p = 0.34, n = 29), but the repeatability of FGM concentrations (i.e. ratio of among-individual variance to total variance, Nakagawa and Schielzeth, 2010) between 2016 and 2017 was 0.35, which is within the range generally observed for glucocorticoids in vertebrates (Taff et al, 2018) and more specifically in roe deer (Carbillet et al, 2020).…”

Reflections of ecological differences? Stress responses of sympatric Alpine chamois and red deer to weather, forage quality, and human disturbance

“…Among our expectations regarding the stress responses of chamois and red deer based on species-specific adaptations to different environments and feeding type, we had to reject our hypotheses The fact that FGM concentrations of both chamois and red deer were independent of visitor numbers during the hiking season between June and October at site 1 stands in contrast to other ungulate studies which showed significant stress responses to anthropogenic disturbance (Carbillet et al, 2020;Creel et al, 2002;Zbyryt et al, 2018). Zwijacz-Kozica et al ( 2013 increasingly independent young posing fewer demands on mothers toward autumn.…”

“…Interestingly, this was the small (1 ha) low-fertility meadow characterized mainly by forest vegetation. Where possible, even forest-dwelling red deer at lower elevations forage on meadows when undisturbed at night, as grasslands provide higher quality (and quantity) food than the forest floor (Bützler, 2001). The larger meadows at sites 2 (a rich meadow) and 3 (also low-fertility overall, but highly heterogeneous; Könz, 2016;Zoller, 1995) thus seemed to provide adequate forage quality for red deer at all times over the summer, while site 1 with its forest vegetation did not.…”

“…show different flight responses to potential predators: The larger and heavier (up to 200 kg; Bützler, 2001) red deer typically flee by trying to outrun a predator, while the smaller (up to 44 kg; Corlatti et al, 2020) and more agile chamois retreat to escape terrain that consists of steep rock faces. Indeed, rocky outcrops providing escape terrain appear to represent a necessary feature of chamois habitat even in forests (von Elsner-Schack, 1985).…”

Artificial Reproductive Technology (ART) Applied to Female Cervids Adapted from Domestic Ruminants

“…Stress is often associated with negative consequences, including decreased immune response and increased susceptibility to disease, reduced growth, and decreased reproductive performance. These adverse effects can impact individual fitness and, ultimately, population dynamics [55]. Stress is defined as anything that throws the body out of homeostatic balance.…”