North American Beaver

North American beaver (Castor canadensis) are nocturnal or crepuscular (active at dawn or dusk) so are not often seen by a casual observer. I wanted a picture of a beaver, so Leonard and I staked out the beaver lodge along Ash creek (Ash Creek Wildlife Area Modoc County CA) mentioned in my last post (Beaver Lodge 08-30-21). We discovered (at least for us) the best time to see a beaver was just before the sun rose as the beaver were returning to their lodge after an active night. From a distance we were able to watch the beaver several mornings.

North American beaver are the largest rodent in North America and the second largest living rodent after the capybara of South America. They can be found wherever there is appropriate habitat throughout most of North America including Mexico. They are golden to dark brown above and lighter below. The hind feet are fully webbed with a divided claw on the second digit. The tail is scaly and flattened from top to bottom.

Each sex has two pairs of large glands in its abdomen, which open through the cloaca. One pair secretes a yellow substance called castoreum while the other pair secretes an oil. Both are used during the mating season and are deposited on piles of leaves, sticks and mud near the lodge (scent mounds) to mark territory.

When excited or alarmed beaver dive and splash the water with their flat tails causing a resounding splash. One night Leonard and I were canoeing on the Pit River in complete darkness – something about me forgetting that although there was a full moon the buttes surrounding the river blocked the moonlight. The “splash” as the beaver dove around us sounded more like a rifle shot than anything else and I felt as though we were in a war zone.

Beaver eat green bark, rootlets, grasses, cattails, tules, pond lilies and other vegetation. Aspen, cottonwood, birch, and willow are favorite foods. Pines are also debarked (particularly in winter).

Beaver were almost hunted to extinction for their pelts and dam-building habits. After reaching dangerously low populations levels, they have rebounded with protection.

Watching the curious beaver swimming in Ash Creek and returning to their lodges was worth the very early morning starts.

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2 Responses to North American Beaver

  1. usermattw says:

    Apparently castoreum smells somewhat like vanilla and is sometimes used in perfumes, and is even FDA-approved as a food additive (though it’s rarely, if ever, used for that anymore).

    Liked by 1 person

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