Anticipatory parental care: acquiring resources for offspring prior to conception.

Many organisms acquire and defend resources outside the breeding season and this is thought to be for immediate survival and reproductive benefits. Female red squirrels (Tamiasciurus hudsonicus) acquire traditional food cache sites up to four months prior to the presence of any physiological or behavioural cues associated with mating or offspring dependency. They subsequently relinquish these resources to one of their offspring at independence (ten months later). We experimentally show that acquisition of these cache sites cannot be explained by conventional arguments such as enhanced survival of the parent or increased reproductive output. Instead this behaviour functions as a form of parental care.