Chemical Signals in the Beaver

Abstract

We examined the information coded in the chemical signaling system in the beaver (Castor canadensis), which has two pheromonal sources, castoreum and the anal gland secretion. It seems that castoreum is used to advertise territoriality and maybe also mediates in the recognition of family members, neighbors and non-neighbors. The anal gland secretion contains multiple types of information including individuality, kinship, family membership and sex. The gas chromatographic profile of the anal gland secretion is individually specific, but profiles are more similar between genetically related individuals than between non-related individuals. Thus, information about kinship can be coded by using the codes for individuality. Family membership can be similarly coded by using the codes for kinship information. This is because beavers live in closed family units, resulting in a higher within-family relatedness than between-families relatedness. Coding for sex information using compounds from the anal gland secretion is both digital (present/absent) and analog (present, but consistently different in the amount between the two sexes). The interrelationship between sex information and other types of information is not yet clear. Although castoreum does not contain sex information while the anal gland secretion does, beavers do not show differences in their behavioral response to either castoreum or the anal gland secretion from males or females.