|
You can
easily see muskrats feeding or swimming about,
as
well as their houses (large) and feeding platforms (smaller heaps of
vegetation). Not able to hibernate, the muskrat usually spends all
his life in the water, dredging up roots and shoots of water plants
from the bottom to eat. In
winter, he still swims below the ice but may eat part of his house
from the inside if food is scarce. Where water is shallow
or absent, muskrat survive the
winter by burrowing in steep banks and feeding on the upland grasses
or crops. The trail here is occasionally
undermined by a bank muskrat.
Muskrats would overpopulate, like rabbits, if not controlled by
winter die-offs (deep freeze), predation by mink and trapping by
man, and by a curious territorial mechanism: In the fall, the
surplus muskrats (the weaker ones) are driven out of the marsh by
the others - mostly to wander until eaten by some predator or run
over by a car.
Muskrats in turn control the cattails, bulrushes, and duck potato
population by eating them out in places, leaving sunny open water
for ducks, fish and the small plants and animals they feed on. The
ideal nesting habitat for water-fowl has a checkerboard of 50%.
openings and 50% dense vegetation. Since plants tend to close in to
form uniform dense stands, the muskrat is vital for creating the
needed openings by dredging moats around each house and "leads" or
"marinas" radiating out from each house.
Rat houses are also much used by ducks and turtles for resting and
sometimes nesting; by smartweeds and cattails for seedling starting
sites; and (when decayed and floating) by grebes and terns for
nests. The new smartweeds and cattails in turn feed new ducks and
muskrats, respectively.
|
