Sherri Guzzi of Tahoe sends this photo and wonders whether beavers could possibly build this rocky dam or whether humans are responsible. I know beavers incorporate rocks into their dam, but I had never seen a dam OF rocks. I decided to ask around like I usually do and thought I’d share the responses.
Sharon Brown of Beavers Wetlands and Wildlife writes “I wouldn’t be surprised if beavers built it as they’ve been known to use whatever is available, including corn husks, old tires, and in one case, money discarded by a bank robber during his escape.”
Skip Lisle of Beaver Deceivers Int’l says “Yes, they will use whatever materials that are available, and can be moved. If there was human involvement, beavers will also adopt any small man-made dam.”
Sarah Summerville of the Unexpected Wildlife Refuge says “Sarah Summerville of the Unexpected Wildlife Refuge writes “I would say yes. Look at all the rocks laying around! They use tires,trash, corn stalks, etc. why not rocks?!”
Mike Callahan of Beaver Solutions says “I’ve never seen a beaver dam made of rock before, but that doesn’t mean it isn’t possible. As we all know beavers certainly do incorporate rocks into their dams. But building the entire dam out of rocks? Unlikely but it is possible since there is such an abundance of rocks at that location. I find it interesting that the shape of the dam certainly looks like something that beavers would build. Plus it seems to have some beaver chewed sticks on it.Since the dam is effectively holding back water it means that either beavers built the entire rock dam, or the rocks were placed by humans and the beavers filled the leaks between the rocks with mud to seal the deal. They certainly do that with old farm stone walls here in New England. It’s always hard to say without seeing it in person, but beavers are likely involved at some level I would guess.
Sherri Tippie of Wildlife 2000 says “This is amazing but I believe it because I’ve seen beaver incorporate large rocks is their dams lots of times.”
Leonard Houston of the Beaver Advocacy Committee in Oregon “we have seen beavers build small rock dams in mountain streams of southwestern Oregon time and time again, seems beavers are quite capable of using whatever is at hand.. we have seen tires, shopping baskets , pasture fencing and a Have-a Heart trap incorporated into dams. Beavers take advantage of down trees roadbeds rock weirs and well just about anything they find in the riparian area…great photo Thanks for Sharing”
And our own Cheryl Reynolds says she’s seen beavers use rocks in dams in Sonoma.
