Persistence of southern flying squirrel winter aggregations: roles of kinship, familiarity, and intruder squirrels

Abstract Southern flying squirrels (Glaucomys volans) are seasonally gregarious and rely on the thermoregulatory benefits of well-constructed nests and presence of nest mates to survive harsh winter conditions. Prior work has shown that kinship components are important to how winter aggregations form in captivity and that relatedness between individuals is higher than expected in undisturbed populations examined in the field. Over the course of 2 falls, 2006 and 2007, we created related and unrelated groups in a laboratory colony at Wake Forest University. We presented each group type with related and unrelated individuals as intruders. Once formed, aggregations persisted when presented with an intruder squirrel. Squirrels from existing aggregations were found in the same nest box 98% of the time. Factors of relatedness and familiarity were crucial in determining whether the intruder was accepted into an existing aggregation or nested alone. We found that related groups were more tolerant of truly novel (...