The Effects of the Mating Season on Activity of River Otters, Lontra canadensis, at Latrines Located in the Humboldt Bay Area, California

Northern river otters, Lontra canadensis, deposit scat and anal gland secretions at locations known as latrines. There are several hypotheses for what river otters communicate through scent-marking at latrines, include: signaling identity, social status, territoriality, resource depletion, and reproductive status. This study will examine the hypothesis that latrines are used for communication of breeding status by testing the prediction that there should be an increase in the amount of activity at latrines during the mating season compared to the non-mating season in the Humboldt Bay area. To observe river otters in their natural habitat, we used non-invasive videography. Remote cameras that are activated by motion and heat were placed in 18 latrines located in the Humboldt Bay area in coastal Northern California. Visitation rate, duration of visits, and behavior during the mating season (February-May) was compared to the non-mating season (June-September). The information from this study helps clarify that latrines are used to signal mating status for river otters, and it has provided additional behavioral details of river otters at latrines.