It had been a while since I had driven down the road that passes beside a large marsh west of here. In the summer, it is dense with cattails. It’s hard to see past the line of cattails lining the road. But now, the weight of the snow and the breaking down of the cattails has revealed…Muskratville!
The snow piled on domed roofs catches the eye and dozens of muskrat abodes have suddenly (it seems) been made visible. Muskrats (Ondatra zibethicus) build a couple of kinds of structures, lodges and pushups. Pushups are smaller than lodges and serve as resting places where muskrats can eat in safety.
Muskrats forage underwater for roots and underground stems of plants such as pondweed, water milfoil, and burr-reed. Using a line of pushups stretching away from its lodge, a muskrat can gather food farther away form its lodge than it could otherwise reach. As well as providing a feeding station, pushups also provide an insulated shelter out of the icy water that can quickly rob heat from the muskrat’s naked tail and feet.
Pushups are created in autumn, when the pond first freezes over. The muskrat chews a hole through the thin ice, often around an air bubble or a spot where marsh gas is escaping. Then the muskrat pushes up a pile of fine roots, submerged vegetation, and other debris to form a dome. As the pile grows, it forms an enclosed cavity on the ice surface.
The muskrat visits the pushup throughout the winter to keep the ice open. Pushups are generally constructed in straight lines, about 12 yards apart, in line with a favoured feeding ground. I’m not sure which of these structures might be lodges, and which might be pushups, but the many structures certainly suggest an active community.
For more on muskrats, see my November 17th post, Busy as a Beaver. You can also learn more at The Marvelous in Nature at Muskrat in our Meadow, and see another muskrat push-up at Back on the Blades.
I so seldom get to see muskrats or muskrat evidence, so this was a pleasant visit to your blog (not that visits here aren’t always pleasant and informative!). We have beavers. I sometimes wonder if the presence of the latter pushes out the presence of the former.
Ellen, I don’t think beavers and muskrats really compete, as they prefer different habitat. Muskrats are closely associated with marshes and cattails, while beavers need young trees, so I wouldn’t think there was a conflict there, but haven’t read anything specifically about it.
Fun to see evidence of both species.
I first read about pushups in the blog of an excellent naturalist, Seabreeze or Seaborne or something, can’t quite recall… 😀
I so appreciate reading blogs where I gain new knowledge of our natural world. Today I learned something I didn’t know about muskrats and I thank you. –barbara
Thank you Barbara. There is so much to know!
LB, it’s good to know you are paying attention! I added a couple of links.
Just found your blog and really enjoying it. Beautiful photographs and informative posts. Thank you for this one. I live very near a marsh and walk our dog everyday on the country road that runs through it. I see these push-ups all over it. Until I read your blog, I was sure they were beaver dams. Some could be however as the local conservation authority was trapping beavers there this past Fall.
Hi Paula, glad you dropped by. Beaver lodges are quite a bit larger than muskrat structures, and use branches, while muskrats work with cattails and plants. Sadly, beavers are often considered a nuisance and trapped and/or killed. They are amazing creatures.
[…] For an assortment of posts about dogs and cats and other animals, drop by the Friday Ark! This week, Willow House Chronicles is represented by Muskratville. […]
[…] One of the routes I can take into town leads through a wetland. I love this attractive place. On one side of the road, cattails line the ditch and it is difficult to see inland. In winter it becomes obvious that this marsh is home to a host of muskrats, whose winter shelters become snow-covered igloos. You can see pictures of Muskratville here. […]