I’ve been noticing a few hares (Lepus americanus) in our neighbourhood over that past few years, but nothing like this summer. During my evening stroll, I can see as many as six hopping around the swings in a local schoolyard. It will be interesting to see how many of them survive the winter.
Checking my old copy of Soper’s book, The Mammals of Alberta, (1964), I find that the snowshoe hare follows on average a 9.6 year cycle. I’m thinking that this year must be at or near a population peak. Soper says that the variation is remarkable: in low years, “it almost completely vanishes from the scene; conversely, at the peak the total population at times is almost unbelievable.” It is reported that in the peak of 1912-1914, the “woods everywhere were infested with hares”; another writer estimated a population of “several hundreds in a 30-acre woodlot.”
Once the peak is reached, the die-off is dramatic, occurring in the space of a few months to a couple of years. As this happens, other populations, especially lynx, follow suit.
How can a population increase occur so rapidly? I guess the expression relating to breeding like rabbits is true. They can have several litters per year. Presumably the inevitable die-off occurs when the population reaches a critical mass that is unsustainable by the existing food supply and the proximity of individuals creates a situation where diseases can spread easily. The resulting surge in predator populations may also be a factor.
For many years, we have had a resident snowshoe hare in our neighbourhood. It’s presence is mostly detectable in the winter months. First thing in the morning there are a new set of tracks in the backyard. The route it follows seems consistent. First a visit to the area under the bird feeders, then down to the spruce tree at the end corner of the yard, and finally along the fence to the front yard, and leaving to explore the neighbouring yards.