Mostly nocturnal, but frequent diurnal activity. Travel distance is highly variable, and related to food supply, suitable habitat, and inherent wandering. No information available. Individuals establish scent posts using their urine, feces, and musk. Most young probably born in March and April in California.
Females have postpartum estrus.
Young weaned in about 4 mo. Few predators other than humans. Food habits of the river otter in Suisun Marsh, central California. Grinnell, J., J. S. Dixon, and J. M. Linsdale. Fur-bearing mammals of California.