Sunday, December 16, 2012

Muskrat Moochers

At Secret Pond, the beaver colony has stored an impressive pile of branches to serve as their winter food supply. This food cache would also appear to be sustaining a large family of muskrats. Though I’m sure that it doesn't constitute their entire diet, just about every time I visit the pond, I see one or several muskrats making away with some of the beavers choice cuttings.  Muskrats are far smaller than beavers –they only weigh 1 to 4 pounds on average, while beavers range from 25 to 65 lbs. Still, when you have at least 8 muskrats, consistently helping themselves to a single food cache, it makes a difference.  To compensate for this, the beavers have to do extra work, which means more trips over land to find more trees to cut and bring back.
A young muskrat helps itself to the beaver's stored branches
In most areas where muskrats live, there tends to be lots of aquatic vegetation for them to eat. The species is very closely associated with cattails, which they utilize both as food and as a primary building material for their lodges. However, in upland areas like ours, where cattails are scarce, muskrats have to rely on different foods like tree bark –and this puts them into direct competition with beavers.
Muskrats propel themselves largely with their whip-like flat-sided tail
The muskrat's back feet are only partially webbed 
The reaction of the beavers to the muskrats is interesting. They rarely lash out at them or try to chase out of their territory. The closest they come to this is when a muskrat is literally trying to steal something right from a beaver’s mouth. When that happens, the beaver will give a nasal whine and maybe execute a downward slap with its front feet. The quick and maneuverable little muskrats can easily avoid being scolded –and often enough, they are able to make off with a bit of stolen food.
One youngster grooms its sibling's back
Lately, when I bring apples down to the pond for the beavers, I can be sure that the muskrats will get most of them. It’s obvious to me that the muskrat’s sense of smell –at least when it comes to detecting apples, seems to be much keener than that of the beavers. Muskrats can zero-in on an apple piece in seconds, while in comparison, the beavers fumble around almost blindly –often missing a chunk floating right next to them in the water. Muskrats move in quickly, and they regularly out-maneuver the beavers in getting to the fruit.  Also, the muskrats anticipate my trips to the pond, and all 6 young ones will often swarm around in the water in front of me, waiting for me to throw something in. The beavers on the other hand, may or may not show up at all. They love apples, but they live by their own schedules, which are generally unpredictable and not so much influenced by the promise of snacks.
The kits start to gather on shore
In cattail marshes, muskrat houses are easy to see. They are 2 to 4 foot high mounds of mud and reeds, which rise from the marsh beds. However, in our area, where there are few cattails to work with, the muskrats inhabit beaver lodges. They don’t live inside the main chamber where the beavers are; instead, they have their own little apartments, usually located off of one of the lodge’s auxiliary entrances. I've seen muskrats bring bedding materials –mostly grasses and sedges into these apartments. And I've seen their young kits huddled in the entrance way, waiting anxiously for their parents to return with food.
"Patches" a white-sided muskrat, adds sticks to the beaver lodge "apartment" 
Some literature states that muskrats will not build lodges with sticks the way that beavers do, but I remember watching one particular muskrat do something similar. This individual –named Patches, was seen adding sticks and mud onto the roof over the part of the beaver lodge that she was living in. You’d think that this would be a job for the landlord to do, but I guess that the muskrats don’t really pay rent –do they.

I often talk about how the beavers are habitat creators and how their work creating ponds benefits so many other animals –from Kingfishers and mink to Wood Ducks and turtles. Still, I don’t think that any creature benefits from the beaver’s good work quite as much as the muskrats. They get a pond, regular food deliveries and a home. Now that’s a pretty sweet deal for the muskrats.
Muskrat kits wait at the lodge entrance for their mother to return with food

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