Sub-adult beavers remain with their natal family to help maintain the lodge and to help collect food for the younger generation of kits for two years (Sun-Lixing, 1997). All members of the family maintain the dam, lodge, and territory (Rosell 1997, Grzimek 1975). These actions are known as cooperative because it increases the fitness every member in the colony. The breeding pair is able invest more energy in their young because the sub-adults decrease their burden. The sub-adults are able to live in a secure, established territory until they sexually mature while helping to maintain and defend their natal colony’s habitat (Cahalane 1947).

Phenotype matching and kin recognition:

Kinship information is thought to be coded in the anal gland secretions of the beaver. By utilizing phenotype matching, beavers are able to identify relatives without previous contact with the individual. Phenotype matching can be learned as a way to identify unrelated individuals that are related to the mate. By sniffing scent mounds marked with the ASG, beavers are able to differentiate between scent mounds created by unfamiliar siblings as opposed to unfamiliar non-relatives (Lixing Sun 1988, 1997).

By using phenotype matching, individuals are able to recognize siblings from another generation that they have not previously come into contact with. Dispersing beavers travel a short distance for their natal family’s territory, on average 10-3 km (Lixing Sun 1988). Males are thought to disperse shorter distances and establish territories and the first available site found. It is observed that beavers exhibit a less aggressive response to neighbors scent markings, as opposed to those of a transient beaver. It is hypothesized that this is due to kin recognition, since neighbors are most likely related. (Rosell, 2002)

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This page was completed in partial fulfillment of the requirements for Biology 323, Animal Behavior, at Davidson College in the Spring Semester 2003.