Résumé
Increasing rainfall deficits threaten the persistence of terrestrial large herbivores, yet, very few studies have investigated the effects of droughts on populations inhabiting anthropized areas, which dominate European landscapes. We investigated how rainfall deficits (measured using the Standardized Precipitation Index, SPI) and local agricultural land use shaped the early growth of fawns and the body mass that they attained by their first winter in a population of European roe deer (Capreolus capreolus) in southwestern France. Using data on 155 new-born fawns, we found that early growth decreased as local woodland availability increased, irrespective of spring rainfall conditions. In contrast, based on data from 218 GPS-monitored juveniles, aged 8-10 months, we found that local landscape composition and seasonal rainfall deficits had interacting effects on winter body mass. The juveniles were generally heavier with higher proportions of meadows in their predicted home range (mean 0.4 kg +/- 0.2 SE), but this difference disappeared following dry summers (SPI < 1). Juveniles with low access to summer crops (e.g., 5%) were significantly lighter following dry autumns (mean -0.9 kg +/- 0.3 SE), whereas this was not the case for those with higher access to these crops (e.g., 20%). Although populations of large herbivores may respond to harsh climatic conditions by exploiting anthropogenic resources, our results suggest that any compensation effects are strongly dependent on the type of anthropogenic land use and the timing of rainfall deficits, calling for explicitly considering how local climatic conditions and human practices may interact in shaping individual performance and, so, population dynamics.