Beavers do not eat fish. Beavers are strictly herbivores, but they don’t eat only trees either! As ‘choosy generalists,’ their diet consists of many species (80+) of woody, herbaceous, and aquatic plants. Most people blame author C. S. Lewis for the common misunderstanding about beaver diet, as he wrote in The Chronicles of Narnia that they eat fish.
Beavers are bigger than you think. Every time I watch beavers with someone who has never observed them in the wild, they remark about the animal’s large size. Beavers can weigh up to 70 pounds and are bigger than people expect!
Beavers do not live in dams. People often confuse the two main structures beavers build. The dam is what creates the pond in which the beavers travel, forage, store food, gather mud, and seek protection from land predators. The lodge is the structure in which the beavers actually live, sleeping the days away safe and warm.
Beavers do not quickly eat all the trees in an area and then leave. Perhaps if a habitat is not sufficient to support a beaver colony long-term, this may appear to be the case. In fact, beaver foraging and damming activity actually serves to promote the growth of many of the plant species they consume, such as willow and watershield.
Beavers do not multiply ‘like other rodents.’ Beavers often don’t reproduce for the first time until age two or three. A mated pair usually has between 2 and 6 babies, called kits, once per year. That’s it! Even the youngsters from the previous year (appropriately called yearlings) hang around and help care for the new generation.
Not all beavers build dams and/or lodges. If we think critically about the function of these structures, we quickly realize that beavers may not actually have to do all that building. For example, if a river is already deep and wide enough, it would be impractical and unnecessary to build a dam. There are also dispersing beavers who may just be passing through an area for whom a simple bank den or burrow suffices. Building consumes a lot of energy, so beavers only do so when needed.
Beavers don’t cause giardia. Yes, the parasite is also known as ‘beaver fever,’ but while beavers may amplify infection they are not often the original source. Other mammals like muskrats, livestock, bears, domestic dogs, and people are as much or more to blame. The parasites are even naturally occurring! Read more here.
Beaver ponds are bad for fish and/or their dams block fish migration. This is a tricky one, and often it depends on the habitat, type of fish, etc. It is important to remember that beavers and fish have coexisted for at least a million years. Current beaver populations are a fraction of what they were before the fur trade, and the fish survived then! Finally, in his book called Eager, author Ben Goldfarb writes about a bumper sticker that reads: Beaver taught salmon to jump.
Lethal management is not easier or cheaper or more effective than nonlethal methods. Lethal control is only a temporary solution and will need to be repeated year after year as new beavers disperse into the habitat left empty from beavers being trapped out. It is more effective to adopt nonlethal, coexistence strategies, like tree-wrapping and flow device installation, that address the problem long-term.
Beavers do not use their tails to carry and pat down mud. But wouldn’t it be cute if they did?!
This post was originally published at https://alisonzak.com/2021/04/07/beavers-eat-fish-and-other-myths/.