North American River Otter (Lontra canadensis)

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Body length: 1.25m both males and females (Kruuk 2006) 

North American River Otter Photo by Jeff Gerew

Weight: Males 9 Kg and females 8 Kg (Kruuk 2006)

Color: Dark brown with a slight variation from upper side to underside with larger nose than some other otters (Kruuk 2006)

Lifespan: About 10 years in the wild and up to 20 years in captivity (Sacramento Zoological Society 2011)

Feet: Fully webbed feet with small circular scent glands on the middle pads of the inner toes (Kruuk 2006)

Range: Historically, in most major waterways in the US and Canada.  Currently in Canada as far north as trees grow, Alaska, California, Utah and the all of the East Coast from New Foundland to Florida (Kruuk 2006)

Home Range: Have a home range of about from 6km to a maximum of 250km of river/lake/ocean shoreline (Kruuk 2006)

North American River Otter Range Map from

North American River Otter Range Map from

Habitat: Rivers, streams, bogs, and lakes in undeveloped forests or developed towns.  Also can be found in rocky sea coasts.  (Kruuk 2006)

Behavior/ Social Structure: North American river otters can be found living alone but often live in family groups of one or two mothers with cubs or in groups of unrelated males. (They live in larger groups at sea).  They have been knows to hunt cooperatively within these groups.  Males and Females live independently of each other for the most part, with some overlap in home ranges.   Can be both diurnal and nocturnal and are active year round (Kruuk 2006).

Communication:  Communicate through scent marking at latrine sites through feces, urine and anal gland secretions (Ben-David).  Also have scent glands on the feet for marking soil and piles of debris (Kruuk 2006).  They also communicate vocally with whistles, grunts, chuckles, snorts, chirps, and growls (Kruuk 2006)

Diet:  Mostly fish, but also occasionally frogs, crayfish, small mammals, birds, and small reptiles (Kruuk 2006)

Reproduction: Typically have one to three cubs but can have as many as five.  Gestation is about 60 days but they can have delayed implantation Stay with mothers for 10 month or more.

Conservation Status: Listed as Least Concern.  Though it is not threatened/endangered, trapping for pelts eradicated River Otters from much of their historical range. CITES Appendix II (ICUN 2011).

Species Survival Plan (SSP) Status:  Green (captive population can maintain 90% gene diversity for 100 years) (AZA 2011).