Vernal behaviour of the yellow-bellied marmot ( Marmota flaviventris)

Abstract

Reproductive and agonistic behaviour were studied in the first 5 weeks post-hibernation. A single male, 5 adult females and one yearling female formed the colony during the first 2 weeks when reproductive behaviour occurred. Three adult females and a second yearling female joined the colony in the third and fourth weeks. The male evidenced a decline in reproductive behaviour throughout the 5 weeks. All adults were agonistic to yearlings. The yearlings did not evidence reproductive behaviour. The rate of agonistic behaviour per female per hour was highest during the fourth week when parturition probably occurred. There was a significant positive correlation between activity of adult females and rate of agonistic behaviour and between activity of all females and per cent, of submissive responses. Older animals had a power percentage of submissive responses than younger animals. Agonistic behaviour occurred between nearest neighbours. During the vernal period, females moved from being concentrated in the centre of the colony to being more widely dispersed. The dispersal was associated with changes in home ranges and with the avoidance of dominant animals by subordinate animals. Subordinate animals failed to raise litters.