American Beaver

NPS photo

American Beaver

(Castor canadensis)

Did you know that Zion National Park is home to the American beaver? You may not immediately think of these aquatic mammals when in the Southwest, but the Virgin River provides a welcome habitat for this river specialist. Sightings are rare, but evidence of the beaver's activity can be seen on many of the park's Fremont cottonwood trees (Populus fremontii). They do most of their tree-chewing during the night when the cover of darkness helps them to avoid predators.

What may surprise you is what you will not see –beaver dams or lodges. Because the Virgin River experiences frequent flooding (10-15 times a year), the beaver has learned better than to try and alter the river's natural course. Zion's beavers instead burrow into the banks of the river to create a lodge that won't be washed away in a destructive flood. These lodges function in the same way as a traditional beaver lodge with a large, dry living area and a submerged entrance to protect the family from unwanted intruders.

Beavers have a very strong social structure and raise their families inside of these bank lodges. A beaver pair can produce two to three young (called "kits") who reach maturity in about two years. Year-old kits will help to care for their younger siblings while their parents are away but will usually move out of the lodge when they reach maturity.

 

NPS photo

There are several aquatic adaptations that beavers use to make the Virgin River their home. One is their distinctive, flat, leathery tail which helps propel them through the water. Beavers also use their tails to warn other beavers of danger. By slapping their tail on the water's surface they send a warning signal that can even be heard by beavers submerged underwater. The beaver's rear feet are also webbed to help them swim. Beavers can hold their breath for up to fifteen minutes, and a two-layered fur coat helps keep them warm and comfortable while underwater.

 

NPS photo / Marc Neidig

Zion's beavers often leave behind clues for you to discover on your visit: head to the Zion Lodge or Grotto stops along the Zion Canyon Scenic Drive and take a moment to inspect the trees growing near the riverbank. Many of these trees will bear chew marks on the base of their trunks, reminding us of the secret lives of Zion's beavers.

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