Better safe than sorry: antipredatory response of female ibex under multiple reproductive and environmental constraints

Predation represents a major selective force for animal populations, with direct consequences on their dynamics and evolution. In most mammal species, antipredatory tactics are expected to be exacerbated in reproductive females, due to parental care and higher fitness cost of predation. Several studies on mountain ungulates have identified steep rocks as elective antipredatory refuges. We used GPS-determined movement behaviour to test the use of refuge areas in Alpine ibex, Capra ibex , from a colony in the eastern Italian Alps (Marmolada massif). We compared movements of reproductive and nonreproductive female ibex along an altitudinal gradient and with respect to refuge areas throughout the spring–summer phases of the reproductive cycle, and between daytime and night-time. Regardless of their reproductive status, females moved towards higher elevation during the peak of the summer and to lower elevation at night at the diel scale. However, reproductive females exhibited a smaller altitudinal shift between day and night and stayed closer to the refuge areas, both during the day and at night, but only after births and during the more demanding phases of reproduction (lactation). We argue that this behaviour is related to females' need to protect their kids from predators because of their kids’ lower mobility, especially in the first phases after birth. By contemporarily showing that differences both in the use of refuge areas and altitude used (linked to resource availability and temperature) between reproductive and nonreproductive females vary throughout the maternal phases, our results also support a resource acquisition–thermoregulation–predation risk trade-off.