Change Of Partners In A Giant Otter Alpha Couple

Very few data are available on the social behaviour of giant otter (Pteronura brasiliensis). In this note I report a change of partners in a giant otter alpha couple observed in the Xixuau Reserve in Roraima, Brazil. The male of the breeding pair disappeared and was replaced by another adult male, previously sighted within the group's territory. The calf of the original alpha couple survived the whole transition and was adopted by the new adult male; the group remained stable in its new form and one year later the couple had a litter of two cubs. For each individual, the frequency of alarm behaviour was recorded and the results show an adjustment of the alpha female to the different behaviour of the two partners.