Arizona #Endangered Species: River Otters

From Smithsonian

Credit: painting by Consie Powell from Kays and Wilson’s Mammals of North America, © Princeton University Press (2002)

The North American River Otter (Lontra Canadensis) is a dark brown, long-bodied, web-footed, big-whiskered mammal weighing between 10 and 30 pounds. Otters live in burrows beside streams, lakes, swamps, and ponds.  They are superb fishermen, but they also hunt frogs, turtles, crayfish, small mammals, and birds.


Like other predators, Otters help control the numbers of their prey species. They happily take introduced alien species along with natives. In a few instances, people have complained that River Otters might be eating trout introduced to Arizona waters for sport fishing.

Otter, Northern River

Otters often eat and sleep floating on their backs. In the picture, a mother is holding her big-nosed child on her stomach.


tracksRiver Otters live where there is permanent food and water. They prefer riparian communities dominated by willows, cottonwoods, birches, and spruce, cattails, red-osier dogwood, black hawthorn, common snowberry, grasses, horsetails, bulrushes, and sedges (Tesky, 1993).


River Otters lived throughout Arizona. Unfortunately, their thick fur made them a favorite of 19th Century fur trappers. It takes 20 to 30 otters to make a fur coat. By 1900, most of the Otters were gone and the fur coats had worn out. During the 20th Century, water pollution and stream diversion for irrigation, flood control, and recreation eliminated most of the best habitat. Today there are few if any Otters left in the State. Ponds and pools along the Agua Fria River near my home in central Arizona might be  suitable for otters, but it is unlikely that any live here.

The State of Arizona Game and Fish Department conservation status ranking for otters and many other wildlife species is included in the species checklists on this website.

Bringing Otters back to Arizona:  Reservoir Dreams

Returning Otters to Arizona would be difficult. Otters are sensitive to water pollution, and could not survive in many of the State’s streams and lakes. Moreover, the banks of irrigation canals and reservoirs aren’t suitable for Otter burrows. We can imagine that we might set aside one of our reservoirs for Otters. Stocked with native fish, protected from pollution and recreation, and planted with preferred vegetation, Otters brought to the reservoir from other locations might set up a colony and the species might once again live in Arizona.

The header image is from Animal Photos.


  • Arizona Game and Fish Department (AZGFD).  List of “nongame” species includes bats:
  • Arizona Game and Fish Department. 1995 (Second Draft). Animal Abstracts Lontra Canadensis sonora. PDF. Unpublished abstract compiled and edited by the Heritage Data Management System, Arizona Game and Fish Department, Phoenix, AZ. PDF.
  • Hoffmeister, D.F. 1986. Mammals of Arizona. The University of Arizona Press. Tucson. Pp. 515-517.
  • Jones, et al. 1987. North American Mammals North of Mexico. Texas Tech Univ.
  • Kays, R.W., and D.E. Wilson.  2009.  Mammals of North America (second edition).  Princeton Univ Press, Princeton, NJ.  248 p.
  • National Wildlife Federation:
  • NatureServe.
  • Navajo Nation Fish and Wildlife Department. 2000. Navajo Endangered Species List. Navajo Nation Fish and Wildlife Department. 2005. Navajo Endangered Species List. P. 2.
  • Smithsonian National Museum of Natural History:
  • Tesky, J.L. 1993. Lutra canadensis. In U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station Sciences Laboratory (2002, September). Fire Effects Information System,
  • Endangered Species Act.  1973. The act and related laws discussed at:
  • U. S. Fish and Wildlife Service:
  • USDA, Forest Service Region 3. 1999. Regional Forester’s Sensitive Species List. The latest update (2007) does not list the River Otter.

I am beginning a series of short articles about the state’s endangered species. For  species that the Department considers Critically Imperiled (S1), Imperiled (S2), or Vulnerable to Extinction (S3).  Please send me your comments and suggestions or bring them to a meeting. The inaugural meeting is at 10:00 am, August 15, 2015, at the Dewey-Humboldt Historical Society Museum on Main Street in Humboldt.

2 thoughts on “Arizona #Endangered Species: River Otters

  1. We canoed the Bill Williams River yesterday (Saturday, April 25, 2020) and saw a baby otter about two miles east of the 95 bridge, right at the mouth of where the north branch of the river comes back into the main branch. I see them regularly when canoeing rivers in the Missouri Ozarks and was surprised to see them here. I know from studying the fur trade that they were once numerous in Arizona so I was happy to see a very young otter in Arizona. We also encountered a couple of beaver dams as well another one about a half mile west of the Alamo Dam spillway a couple of weeks ago while up there hiking. (We also encountered a Mohave rattler and got a picture of him, but unfortunately weren’t fast enough to get the otter on camera. We’ll be back next weekend and we plan to lounge around that area in case one makes a dash between the reeds along the river’s banks so we can try to snap a picture.

    Liked by 1 person


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