Information on Beavers for Kids

Beavers are amazing creatures. These rodents are fast swimmers, and they’re no slouches on land either. They breathe air, but they live in a lodge which can only be reached underwater. They can take down trees many times their size. They live all through northern North America, Europe, and Asia, anywhere there are trees and water. Their dams affect the whole local ecology!

A beaver’s work is never done

If you worked as hard as a beaver, you’d be working the whole night through whenever the pond’s not frozen. Beavers are nocturnal animals, and they’re always busy building and fixing their dams. Some beavers have to rebuild their dams every year!

You’d start by finding a nice stream of just the right size, with lots of nearby trees. Beavers need those trees to build a dam across that stream. First, they plant vertical poles across the stream. Then they fill in the spaces between the poles with branches and plug the holes with weeds and mud. When it’s done, the dam holds back the water in the stream and turns it into a beaver pond. The pond has to be nice and deep, because the only entrance to the lodge will be underwater.

The largest beaver dam in the world is nearly half a mile long. It was found in northern Alberta, Canada, near Fort McMurray (where the oil sands are). It’s the only animal-made structure that can be seen from space!

When the water’s deep enough, you can build your lodge. First, the beaver piles up all the sticks and weeds and mud. Then the beaver gnaws out an entrance and living quarters inside that pile. The passageway starts off underwater and leads above the waterline.

Inside, there’s usually two platforms. One’s for shaking off the water, drying off, and eating. The other is where the beaver family sleeps. There’s also a small air hole up top.

In late fall, it’s time to get ready for winter. That means plastering the lodge with lots of insulating mud. When the mud freezes, it’s as hard as concrete. This helps to make the lodge safe from hungry predators who’d want to dig the beavers out. That way, beavers can stay safely in their lodge after the pond freezes and the weather gets really cold.

Getting ready for winter also means storing a winter supply of food. Beavers don’t hibernate, so they have to eat. They like eating the under-bark of tree branches, but it’s hard to get to trees when the pond’s frozen and the snow’s high. It’s also dangerous, because there’s all sorts of hungry predators out there. That’s why beavers collect their winter food before the pond freezes, and poke all those branches into the bottom of the pond. That way, they can swim out under the pond ice and get a nibble any time they like, all without ever leaving their pond.

Not all beavers have dams! Beavers who find a nice, deep pond don’t need dams. Instead, they build their lodges straight against the bank. The same goes for beavers who live in tidal river mouths, which are called estuaries.

Super-powered beaver teeth

A single beaver can cut down dozens of trees a year. They do it by gnawing at each side, a little at a time, until the tree comes down. You can always tell when a tree’s been taken down by a beaver, because the centre will have a pointy stump and teeth marks will be visible. An adult beaver can take down a six-inch tree in just ten minutes!

Beavers eat the under-bark of most trees, and use the rest of the log for their dams and lodges. They also eat cattail shoots and pond lilies. They’re strict vegetarians, and never eat fish or other animals.

With all that gnawing, a beaver’s teeth wear down a lot. It’s a good thing they also grow back fast. A beaver’s teeth never stop growing. If they didn’t keep gnawing them down, they’d grow out of control!

If you get a chance to see a beaver up close, you’ll see that the outside of its teeth is orange. This is a hard enamel coating. The back of the beaver’s teeth are covered with a softer dentin, which wears down faster than the enamel. This keeps the edges of the beaver’s teeth nice and sharp.

The beaver’s multitasking tail

A beaver’s tail is just as long as the rest of the beaver. That makes it a great kickstand for balancing the beaver when it’s sitting up and gnawing at a tree.

When the beaver is swimming, the tail stretches out behind it. It’s buoyant and it steers the beaver. It’s like the beaver’s rudder.

Beavers are social animals, so over a dozen beavers may be sharing the same pond and lodge. If a beaver sees danger, it slaps the water surface with its tail to warn the others. This warning signal is very loud and can be heard a long way away.

In the fall, a beaver’s tail is where it stores extra fat. At this time of year, the tail can grow up to three times its regular size! All that extra energy’s going to be useful in the winter.

Just about the only thing a beaver doesn’t do with its tail is use it to slap down mud into its dam. That happens only in cartoons.

Ponds to meadows

A beaver dam slows a stream right down. All the sediment that the stream carries slows down as well, and sinks down to the bottom of the beaver pond. Cattails love the still water and filtre out many of the pollutants. That’s why the water downstream of a beaver dam is cleaner than the water coming into the pond.

By making a new pond, the beaver has made a brand-new wetland. Wetlands are very important environments. They provide habitat for many different types of animals and plants. They store water during droughts, and keep spring runoff and heavy rains from wide scale flooding.

As the sediment builds up, the pond gets shallower. In a few years, it gets too shallow for the beaver to use, and it goes to look for a new place. Even when the abandoned beaver dam breaks, a lot of that sediment remains behind, and more gets built up all the time. The pond gradually turns into a meadow with very rich soil.

Oops!

Beavers don’t ask people ahead of time where to place their dams or which trees to cut down. That’s resulted in a lot of flooded farmers’ fields and even a few flooded suburbs. People aren’t happy when their houses flood because of a rodent’s architectural aspirations.

One small family of beavers even took out some of the historic cherry blossom trees in Washington DC. It became a federal issue which was argued in the US House of Representatives. Some people were pro beaver, arguing that the beavers were native sons and the cherry trees weren’t. Other people were pro cherry blossom trees, although they didn’t really want the beavers harmed. As the National Park Service biology technician Julia Long said, “This is one optimistic beaver. He thinks he can build a dam across the Tidal Basin.”

Did you know:

* That beavers can weigh up to 100 pounds?
* That there’s a picture of the beaver on the Canadian nickel?
* That beavers respond to the sound of running water, even if it’s on dry land?
* That beavers also build canals to float logs to their dam?
* That beavers helped cause the birth of Canada?
* That beavers were once declared to be fish?
* That a beavertail is not made from beavers’ tails?
* That the beaver is the national symbol of Canada?

What is a beavertail?

BeaverTails are a fried dough pastry that’s stretched and shaped to look like a beaver’s tail. They’re usually sprinkled lightly with sugar and cinnamon before being served, although you can also get BeaverTails with all kinds of different toppings. You can get BeaverTails in Ottawa’s Bywater Market, which is where they were first made, but there’s a lot of other places selling BeaverTails now as well. They’re amazingly good!