We investigated the activity patterns of a European roe deer (Capreolus capreolus) population living in a forested Apennine area in central Italy, in order to shed light on the environmental and biological factors that were expected to account for the observed activity patterns on daily and yearly bases. Daily and seasonal activity patterns of 31 radio-collared roe deer were assessed through sessions of radio tracking for a total period of 18 consecutive months. Roe deer showed bimodal activity patterns throughout the year, with the two highest peaks of activity recorded at dawn and dusk. Activity patterns of males and females differed during the territorial period (from early spring to late summer), whereas they did not during the nonterritorial period. Most likely, behavioral thermoregulation can be held responsible for variation of daily activity patterns in different seasons. In winter, for instance, activity during the dawn period was significantly higher than in other seasons and daylight activity was significantly higher than at night. Nocturnal activity was highest in summer and lowest in winter. During the hunting season, moreover, roe deer showed lower activity levels than during the rest of the year. The prediction that roe deer would show lower activity levels during full moon nights, when the predation risk was assumed to be higher, was not confirmed by our data. Activity rhythms in roe deer were thus subjected to both endogenous and environmental factors, the latter working as exogenous synchronization cues. Accordingly, in changing environmental and ecological conditions, a circadian cycle of activity could be seen as the result of complex interactions among daily behavioral rhythm, digestive physiology, and external modifying factors.
This study investigated the anti‐predator strategies adopted by 19 radio‐collared female roe deer during the fawning season by monitoring their spatial behaviour and habitat selection by means of radio‐tracking. The study was carried out in a forest area of the Apennine Mountains (central Italy), where wolves are natural predators of roe deer and in summer fawns are more frequently predated than adult roe deer. The presence of fawns was monitored by means of direct observations. Roe deer fawns are known to adopt the hiding strategy during the lactation period, when they lie concealed for long periods waiting for their mothers' milk. As a consequence of this, the home‐range sizes of mothers were significantly smaller than those of non‐mothers during the summer lactation only. In contrast, no significant difference was found in spring, when fawns were absent, or autumn, when they were already weaned. In order to increase the success of the hiding strategy adopted by their fawns against wolf predation, mothers selected denser habitats (deciduous coppice forests) that provided denser undergrowth vegetation and limited visibility. In doing so, mothers traded open areas for forests throughout the fawning season. Indeed, mothers made significant habitat selection throughout the monitored period, and this was marked after the birth of fawns. In contrast, non‐mothers generally used habitat types according to their availability. During lactation, the correlation between habitat use by mothers and habitat visibility (assessed using the form of a standard‐sized roe deer) was inversely significant. These results taken together highlight the importance of anti‐predator strategies adopted by roe deer mothers during the critical phase for fawn survival.
The range-shifts of many species are lagging behind climate change, meaning that those species are likely to experience increases in average ambient temperature. Heat-sensitive species may experience increasingly precarious trade-offs between investment in thermoregulation versus other key processes as the climate warms. We investigated the potential for trade-offs to exist between behavioral thermoregulation and foraging, studying a typical heat-sensitive endotherm: the Alpine ibex (Capra ibex). Ibex use higher altitudes when it is hotter, which could restrict them from more profitable foraging areas at lower altitudes. We investigated this potential trade-off using data on the altitude-use and activity budgets of 43 marked males collected during the vegetation growing season in Gran Paradiso National Park, Italy. We used structural equation modeling to assess the support for models linking ambient temperature, altitude-use, vegetation productivity, and foraging time. Ibex migrated to higher altitudes during spring and summer, maintaining their ambient temperature within a very narrow band. Consequently, when it was warmer ibex utilized areas that were less productive, as indicated by lower normalized difference vegetation indices, and consumed lower quality forage, as indicated by lower levels of fecal crude protein. Ibex did not compensate behaviorally for reduced forage productivity by adjusting their foraging effort. We identify a trade-off between thermoregulation and foraging in ibex, which could affect this species negatively in the future. Such trade-offs could be a general phenomenon for heat-sensitive species. Our study reveals that behavioral thermoregulation can exert a strong influence on animal distributions, even overriding resource productivity in importance.