Beaver tails are wide, flat and paddle-shaped, while muskrats have long, skinny tails with flat sides. You can usually see a muskrat’s whole body when it is swimming. With beavers, you often see only their large wedge-shaped heads.
Let’s look at some other ways you can tell the differences between beavers and muskrats.
Size and color
Beavers, usually weighing between 35 and 60 pounds, are much larger than muskrats, which top out at 4 pounds. Both come in various shades of brown.
Look in the mud near the water for footprints. Both have claws designed for digging. Beavers have five very distinct toes on their front feet. Their hind feet are about 5 inches long and are webbed. A muskrat’s small front feet appear to be four-toed, but there is a tiny fifth toe that is hard to see. Their narrow hind feet, about 3 inches long, have five toes and are only partially webbed.
Also look for tail tracks between the footprints. Are they long and skinny or do they make a wide path?
Beavers and muskrats are the only mammals that build their homes in the water. Sometimes they create homes by burrowing into the banks bordering the water where they swim and fish. Beavers use a lot of mud to help hold layered logs and sticks in a dome shape, while muskrats pile plants, including cattails, over a firm base such as a tree stump, using a little mud to hold the shelter together.
Ahhh, but now it gets confusing. You spot a cute furry brown critter coming out of a definite beaver lodge. It must be a beaver, right? Not necessarily. Muskrats often move into beaver lodges, even while the beavers are there. Kevin Munroe, park manager at Huntley Meadows, said, “Muskrats may provide another set of eyes looking out for predators.” (Locally, minks, otters, foxes or hawks pose danger to muskrats and baby beavers. Adult beavers here don’t have to deal with their usual predators — bears or wolves.)
This is an easy one, because muskrats don’t build dams — only beavers do. Beaver dams create deeper ponds of water to allow for underwater entrances to lodges, to move food and building materials, and to help protect from predators. By building dams, beavers provide a safer habitat for muskrats, too. Muskrats help beavers by eating lots of cattails and opening up paths for beavers to swim through.
So, grab your detective hat now and see if you can tell which is which.
— Ann Cameron Siegal