Sex-specific adjustments in habitat selection contribute to buffer mouflon against summer conditions
Abstract
In the context of global warming, investigating how animals buffer against the hottest conditions is a crucial issue. We focused on habitat selection in a French Mediterranean mouflon population during 2010-2012 summers. Using locations and temperatures recorded on GPS-collared individuals, we assessed thermal cover provided by different habitats and analyzed sex-and scale-specific habitat selection and its thermal consequences for mouflon. At the home range scale, females (n = 26) avoided unsafe plateaux and selected steep refuges, trading off thermal cover with better conditions for lamb survival. Larger males (n = 18), not constrained by young rearing and expected to respond more strongly than smaller females to hot conditions, rather selected forests on plateaux providing thermal cover. In terms of movements, both sexes selected forests during hottest days. Males also took advantage of food and thermal cover provided by moorlands on plateaux until twilight, whereas females traded off food and thermal cover with refuges. Thermal cover significantly influenced habitat selection when temperature at the closest weather station exceeded 17.1 degrees C (95% confidence interval = 14.9-19.7) in males and 15.5 degrees C (95% confidence interval = 13.9-16.5) in females. Above these thresholds, ambient temperatures experienced by mouflon increased more slowly than temperatures at the weather station (males: 0.77 degrees C [95% confidence interval = 0.74-0.79] per 1 degrees C rise at the weather station, females: 0.75 degrees C [95% confidence interval = 0.73-0.76]) and more slowly than below these thresholds (males: 0.89 degrees C [95% confidence interval = 0.85-0.93], females: 0.94 degrees C [95% confidence interval = 0.89-0.98]). These findings suggested that habitat selection contributes to buffer mouflon against summer conditions but raised questions on energetic and fitness costs in areas where summer temperatures are predicted to increase further.