You’ve probably seen the statistic tossed about that our current beaver population is about a tenth of what it used to be. That’s always seemed right to me, but today I really looked a little closer at the numbers. This article, (which dissapointingly isn’t so much an article as it is the back-of-a-cereal-box collection of facts, some of them accurate), describes a pre-contact population of American beaver at 60,000,000 animals. I was curious how that would actually play out regionally. Leaving out Hawaii which never had beaver, and Alaska which I don’t think was included in this guestimate, that leaves 125000 beavers per state. Not really a helpful statistic when you think about the differing sizes and amounts of water per state.
But what if you look at water miles for the entire contiguous US, Wikipedia tells me we have 160,820.25 square miles of water. Now, this makes a little more sense. 60,000,000 beaver means about 373 beavers per every 27,878,400 feet of water. That works out to be about 46 colonies for every square mile of water. Or if you are looking at the 35,000,000 miles of river in the United States, that’s about 17 beaver per every mile of stream.
17 per mile! That means that the beaver population of Martinez between Safeway and the train station would more than triple. For California’s 7736 miles of stream that works out to be about 131,512 beavers historically. That’s still not exactly right either because some of them were in lakes and larger bodies of water, but you get the idea. That’s A LOT of beaver.
So the next time you read an article saying that the beaver population has rebounded, think about the 90 percent of those numbers that are still missing. I’m not even sure that the existing population of beavers is larger than or equal to the number of beavers killed every year. Does Fish & Game keep those statistics?
