Beaver biology

Beavers felling trees

I'm pretty sure this is a diorama somewhere, but you get the idea.

Beaver skull

The orange on the front surface of the front teeth is a special enamel coating that helps that side wear slowly, giving each tooth a sharp edge. And sharp they are: a beaver can drop a tree two inches in diameter in just a few minutes.

Here are a bunch of cool things to know about beavers:

  • The American beaver is the largest rodent in North America. And in all the world, only the South American capybara is bigger.
  • Unlike other mammals, beavers grow throughout their lives. In the wild, a beaver might live ten to twelve years and weigh as much as 70 pounds. (The largest modern beaver on record weighed in at a whopping 110 pounds.)
  • A beaver's brain is small relative to its body weight. A beaver-sized human would have a brain fifteen times larger than a beaver's.
  • All rodents, including beavers, have front teeth (incisors) that just keep on growing. It's the constant chewing that beavers do that wears them down and keeps them even.
  • A beaver couple cuts down some 400 trees to make a dam.
  • The largest beaver dam on record is 2,790 ft in length—more than half a mile long—and was discovered via satellite imagery in 2007. (That's twice the width of the Hoover Dam, which spans "only" 1,244 feet.) It's located on the southern edge of Wood Buffalo National Park in northern Alberta.
  • Beavers are vegetarians, eating bark, twigs, roots, and aquatic plants.
  • They stay active all winter, living off a supply of branches that they stockpiled and anchored to the bottom of the pond earlier in the year.
  • When beavers run out of trees near their ponds, they dig canals to nearby areas with more. (That way they don't have to leave the water. Which is good, because they're slow and awkward on land.)
  • These guys are made to swim. They have thick, waterproof coats and a layer of fat to keep them warm in the water. Their webbed toes act like swim fins, and their broad tails help steer, like rudders. Valves in their noses and ears close up when swimming to keep water out. Clear membranes cover their eyes, like goggles, to protect them from things like wood chips in the water. And flaps of skin on both sides of a beaver's mouth close behind its front teeth to keep it from swallowing pond water.
  • A beaver can swim five miles per hour and spend 15 minutes underwater without coming up for a breath.
  • A small, land-dwelling beaver called Paleocastor lived here in North America some 20 million years ago. It built complex, spiralling burrows. Some filled with debris and fossilized, creating twisted stones called "devil's corkscrews."
  • Animal Planet puts beavers at number two on their list of the top-ten animal troublemakers, because they cause some $100 million in property damage every year.
ChocolateOreo123's picture
ChocolateOreo123 says:

I <3 Beavers! they are so cute! especially in cartoons. and platapusses

posted on Sun, 01/20/2013 - 3:50pm
Anonymous's picture
Anonymous says:

These are my new sixth or seventh favorite animal. Adorable.

posted on Fri, 01/27/2012 - 4:24pm
Anonymous's picture
Anonymous says:

they are so cute

posted on Thu, 10/28/2010 - 10:00am
Anonymous's picture
Anonymous says:

beavers are cool and the only thing i know about them is that they swim,eat wood, and paople made hats out of them in the old days!!!

posted on Fri, 10/15/2010 - 10:50am
Anonymous's picture
Anonymous says:

this is the coolest thing i've ever seen....here in Minneapolis. I have only been here for like 5 mins and i am very impressed. the beavers are encredibly adorible and i just want to cuddle with them. It's very interestin got see the behavior of these magnificent animals.
-A

posted on Sun, 09/19/2010 - 12:23pm
Anonymous's picture
Anonymous says:

Baby bevers are so cute :) i just want to go up to one and pet it because it's fur looks soft.

posted on Sat, 09/04/2010 - 9:02am
Anonymous's picture
Anonymous says:

i like the bevers they are interesting and i want to see beavers in person.

posted on Sat, 09/04/2010 - 8:59am
Anonymous's picture
Anonymous says:

i am soooooooooooooooooo with you

posted on Thu, 10/28/2010 - 9:58am
Anonymous's picture
Anonymous says:

how old is the beavers mom and the beavers

posted on Mon, 08/16/2010 - 2:44pm
Anonymous's picture
Anonymous says:

what do beavers eat?

posted on Fri, 08/20/2010 - 11:12am
Anonymous's picture
Anonymous says:

the eat logs

posted on Thu, 10/28/2010 - 10:01am
Anonymous's picture
Anonymous says:

how long does a bever grow into a adelt

posted on Sun, 08/08/2010 - 12:40pm
Anonymous's picture
Anonymous says:

the beaver are reley cool iliket it alot the babies are reley cuite

posted on Wed, 08/18/2010 - 11:41am
Anonymous's picture
Anonymous says:

Baby Beavers are so awesome and cute! in some way they are different then the Older Beavers. They have a personalitly that is strang...they actually aren't that afraid of the human and would get along but the adult beave don't alow it. They believe that human should always stay away and that they are the King of the humans.

posted on Thu, 08/05/2010 - 1:39pm
Anonymous's picture
Anonymous says:

BEAVERS ROCK AT THEIR JOB.

posted on Mon, 08/02/2010 - 10:23am
Anonymous's picture
Anonymous says:

beavers are awesome

posted on Mon, 08/02/2010 - 9:24am
Anonymous's picture
Anonymous says:

they swim

posted on Wed, 07/21/2010 - 12:08pm
Anonymous's picture
Anonymous says:

my mom made me run into the shore!!!!!!!!!!!!!!!!

posted on Tue, 07/13/2010 - 10:50am

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Allowed HTML tags: <a> <h3> <h4> <em> <i> <strong> <b> <span> <ul> <ol> <li> <blockquote> <object> <embed> <param> <sub> <sup>
  • Lines and paragraphs break automatically.
  • You may embed videos from the following providers vimeo, youtube. Just add the video URL to your textarea in the place where you would like the video to appear, i.e. http://www.youtube.com/watch?v=pw0jmvdh.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Images can be added to this post.

More information about formatting options