This week, I had the opportunity to spend some time with an under-recognized species, the muskrat. I had always classified them in my mind as small beavers, without the landscaping abilities and keystone position beavers hold. In my narrow view, they did many of the same things that the beaver did, just to lesser degrees. Smaller vegetation, smaller lodges, everything just....well....smaller. Many people seem to have a genuine disdain for them starting right with the name --- MUSKrat, for those that don't like musk; and muskRAT for those that don't like rats. I'm starting to favor the native term for them - muskquoshes which feels more dignified and fitting. After all, muskrats are more than big swimming rats with long tails (even though that is what they look like). In fact, they are actually much more closely related to voles than they are rats!
I came across this pair while looking for ducks - and discovered how curious, social, and NOISY they are. They were non-stop action, bringing greens and root balls in constant fashion into a bank den which they had built on the side of a quiet pond. During the warmer seasons, they will move into beaver lodges, or tunnel into the bank of a pond. In the winter, they construct mini-versions of a beaver lodge, only crafted with with soft grasses and perhaps a few sticks. These "push-ups" don't provide much predator protection for the animal, but rather gives it a spot to get out of the water, dry off, and the dry grass helps to retain some body heat. However, these are very easily invaded by predators of muskrats such as members of the weasel family, bobcats, foxes, and coyotes. The bank dens however, are much more elaborate and provide for areas to store food, dry off, sleep, and raise young. They are generally also harder for predators to invade. Muskrats will even share a lodge with beavers (especially in winter) but if there is conflict, it is generally the muskrats that move out.
Muskrat sign is certainly more subtle than beavers, since they construct homes which are easily overlooked as balls of grass. They will often forage underwater, taking foods like cattails (especially the roots), reeds, tender green aquatic plants, as well as mussels, crayfish, and a variety of insects. When they eat plant material, they will generally make the "classic" 45 degree angle cut of the stem - much like is seen with animals like hares; but the large teeth may leave "steps" in the forage like that from porcupines and beaver. Being fairly large rodents, their tracks have the typical rodent shape with the interesting addition of having stiff hairs along the toes which sometimes show in mud or soft snow. These hairs are thought to provide some "lift" (like tiny snowshoes!) as well as add propulsion when swimming. While watching this pair swim, I noticed how powerful they are in the water - with the tail aiding in providing propulsion, by moving in a serpentine fashion. When moving outbound to forage, they moved cleanly and quickly through the water. Returning with food in their mouths, they more resembled snow plows -- but still cut through the water with amazing speed and power.
What I found most interesting - and confusing - was the amount of noise that one of the pair made. Although one animal moved about completely silently (as you would expect for a prey animal moving in bald eagle, snapping turtle, and mink habitat!) the other had a constant running dialogue that almost sounded like a dog squeaky toy. When it went into the bank den, I could still hear it moving underground beneath me, still commenting. I would occasionally lose the animal in the thick reeds at the edge of the pond - but all I needed to do was follow the sound, and soon enough - I'd be back on the trail. I have done some research on muskrat sounds, and come up empty handed. A sample of a similar sound can be found here: https://macaulaylibrary.org/asset/138594 -- in which the recordist speculated that the sounds were of a male attempting to copulate with the female. There was no indication of this here - the animals were sometimes separated by thousands of feet and the sounds continued. If anyone has some insight, I would be most interested!
Another interesting feature of muskrats is visible in the photo above -- the orange teeth. Muskrats (along with beavers, porcupines, and most of the rodents except the groundhog) chew a remarkable amount of roughage, so the large, sharp incisors in the very front of the mouth are fortified with iron to make them stronger, and they are backed with softer dentin. These teeth grow continuously throughout the life of the animal - and without them, they would likely starve to death. Mother Nature has put these teeth into overdrive, protecting them with a strong cover. They also meet in the front of the mouth in a "scissor" pattern, with each tooth sharpening the opposite one of the pair- this way, they are always in ideal condition to chew the roughage which makes up the bulk of their diet.
Although I couldn't find proof of my theory, I suspect that the "talking" muskrat was gathering soft greens and foods to feed a young litter. Muskrat breeding season runs from March through August, and the gestation is only 28 days --- and they are weaned at 21-28 days. The average litter is 6-7 young. Doing the math shows that they can breed like rodents! Feeding that many young takes a lot of deliveries of groceries, and I can certainly say that the talkative muskrat made an immense number of trips, each carrying bouquets of food into the bank den. Equally interesting is that all of these animals need to disperse and find their own territory once they wean in order to avoid over-populating the natal area. At any given time over the summer, there are a lot of muskrats looking for homes!
An afternoon encounter brought into perspective an unrecognized species for me - an animal which I had largely taken for granted, shared space with but never actually understood. And I realize, watching the steady, constant work pattern of these animals, that I still don't understand them, but I did gain an appreciation for their industrious nature and it left me wanting to know more, looking for the opportunity to watch them again and get a wider view into their world.
For those of you that have enjoyed my Instagram quizzes --- it seems that my page may have been deactivated. At a minimum, I'm not even able to login nor recover my password. If anyone is good at teasing apart Instagram problems, I'd appreciate a hand! I've done as much self-help as I know how to do...... And once I've re-established a page, the quizzes will be back!
'Tis the season for nest building!