In 1975, the beaver was named the official state animal of New York. The decision was not without controversy, because the animal had already been claimed by Oregon 6 years prior. However, legislators and the governor felt that the animal’s ties to New York were too strong to ignore.
In the early 1600s, a beaver pelt trading post near what is now Albany encouraged exploration and settlement of upstate New York. And through the 19th century, trapping of beavers and trading in their pelts remained an important part of the state’s economy.
These days, trapping of beavers is only used to control their population, which has rebounded since the early 20th century. This has allowed beavers to return to areas they had previously abandoned. Beaver populations are in such rebound that they’ve even been able to build a 2800 foot long dam in Canada that’s visible from space!
What’s even more remarkable is that beavers use their teeth for this job. Beavers have remarkable adaptations to their teeth that make this possible. You should not take this as an indication that chewing on wood is a good thing for your teeth!
Beaver Bonus: Teeth That Don’t Stop Growing
Beavers are the largest rodents in North America. Rodents have very different teeth from most mammals. Most mammals develop a couple sets of teeth, which grow during development then stop. If you think your teeth are growing later in life, it’s probably receding gums or hypereruption caused by a loss of contact with an opposing teeth. But rodents have teeth that keep growing all their lives.
This is both a benefit and a burden. Rodents have to constantly gnaw hard substances to keep their teeth from getting too big for their mouths. Beaver teeth have really extreme growth, up to 4 feet a year! That’s longer than the entire body length of an adult beaver!
Because they’re not worried about wearing their teeth down, beavers are free to chew on as many hard objects as they can get their incisors on!
Teeth That Are Literally Made of Steel
If you’ve ever looked at the incisors of beavers, you might have thought they were good candidates for teeth whitening. Their teeth usually look orange or brown, not bright white like human teeth. This isn’t staining from their environment, it’s actual iron in their tooth enamel! As you might suspect, that iron makes their teeth stronger and better able to cut through wood.
But here’s what’s strange about these beaver incisors: they only have enamel on the front of their teeth. The back surfaces of their incisors are exposed dentin. This might seem like a disadvantage, but it actually helps keep the beaver teeth sharp. Because the dentin at the back wears away faster, it creates a sloping angle on the teeth, a perpetual edge.
Beaver teeth are so good at cutting wood that they were used a tools by early humans. The oldest known wooden statue is believed to have been carved in part with tools made from beaver jaws!
Your Teeth Are Meant for Chewing Food
Understanding beavers’ special adaptations for chewing wood can help you understand why they can chew on wood, but you shouldn’t. Our teeth are meant for chewing food only. Using your teeth for chewing other things, such as fingernails, pen lids, even ice or unpopped popcorn kernels can badly damage them.