by Stan Tekiela
August 8, 2003
Photo by Stan Tekiela©
Nothing in nature ever stays the same. It's always in a constant state of flux. Just
as the prairie will gradually transition into a forest and the lake will someday fill with sediment and become
a marsh, everything in nature is changing.
Animal populations fluctuate also. Ducks, pheasants and white-tailed deer are good examples of this on-going
change. The over all populations of these animals go up and down depending upon many factors.
Snowshoe hares and lemmings populations cycle up and down in predicable patters. Roughly every ten years
the population of snowshoes reaches a peak and then suddenly drops off. These ebbs and flows of populations
are not fully understood. Many speculate the population booms and busts are tied to crowding, available food,
and the number of predators such as the Northern Goshawk and the Canada Lynx which feed heavily on the snowshoe.
The Eastern Cottontail (Sylvilagus floridanus) is not a species with a well defined population cycle like the
snowshoe but it seems to me that they are at an unusually high population right now. Seems like no matter where I
go there is another bunny.
The Eastern Cottontail is the most common rabbit throughout the northland. And its uncommonly high population
might have something to do with the fact that this bunny reproduces at an astounding rate. Females initially breed
in late February and March. Gestation lasts only a month so the first baby cottontails are born very early in
the season. Most litters range from four to eight with six as average. In the northland a typical female will
produce up to 4 liters per year.
In some areas the female population reproduces synchronously (all at the same time). Litters are born to
various females within a few days at two week intervals. This synchrony lasts through the entire season.
The blind, naked young open their eyes at one week of age and are weaned from their mother's milk in less
than a month. As soon as the babies are furred and hopping around on their own the mother has nothing more to do
with them. Young females are sexually mature at 3 months old.
Within hours after giving birth the female often mates again. Presuming that none of the offspring die, a single
pair of cottontails, together with their offspring, could produce 350,000 baby rabbits in five years. However the
death rate of the Eastern Cottontail is incredibly high with few individuals living longer than one year.
Combine the cottontail's prolific reproduction ability and a sharp decrease in predators such as the Red Fox
which is highly susceptible to mange, a fatal disease, and you can have very high numbers of cottontails.
So enjoy the cottontails while you can. Because, as I mentioned earlier, nothing ever stays the same in nature.
Next year the Eastern Cottontail may be scarce again.
Until next time...
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