Whoever loves snow and cold, like we’ve had this month, please raise your hand.
Okay, you in the back. You may lower your hand now.
Let’s face it. As February grinds into March, the ranks of the smiling have thinned mostly to snowplow drivers, ski area owners and, perhaps, auto body repairers.
And white-tailed jackrabbits; brown in the summer and white like snow in the winter.
When your house is on the open prairie, and lots of things daily want to eat you, life is complicated. It sure helps if you can blend in with your surroundings. Montana hosts seven species of hares and rabbits. They are all in the same family, Leporidae, but have several differences.
Among the rabbits we are home to the pygmy rabbit and three species of cottontails.
The larger hares number three species: snowshoe, and black-tailed and white-tailed jackrabbits. Despite their name, jackrabbits are hares. And the white-tailed version, which can weigh up to six pounds, is much more numerous in Montana.
That is the species that more folks than usual are reporting this winter.
One fellow north of Great Falls even asked if there could be something like a damage hunt because he had too many jackrabbits and they were into his pasture.
I kid you not.
For years, it was more common to hear people ask what happened to all the jackrabbits they remembered from their younger days. This winter, however, there seems to be something of a resurgence in jackrabbit numbers.
What’s going on?
The short answer is no one knows for sure. Or it’s complicated.
What we do know is rabbits and hares are prey species, and predator and prey species populations generally go in opposite directions, occasionally intersecting.
When predator species are on the upswing, prey species numbers go down until they get so few, predator numbers decline. Then the prey species start to increase.
As prey, jackrabbits like their cousins the true rabbits, live short, fertile lives.
The jackrabbit breeding season extends from late February into July. Gestation lasts four to six weeks and litter sizes average four to five young.
Females can breed again soon after giving birth, so that a female can have four litters a year.
All those numbers mean one female jackrabbit can have an average annual output of 15 offspring. And females can breed when seven months old.
Again, looking at the numbers, if half of a jackrabbit’s young annually are female and half survive their first year to reproduce, one female in a year can have about 55 grandkids (grand bunnies?).
That’s a lot of food for their numerous predators; like coyotes, bobcats and fox on the ground and raptors from above.
But there are other factors involved in jackrabbit population cycles – things like habitat destruction, disease, and severe weather. Humans play a role, too, though mostly from habitat degradation and destruction.
Of the two jackrabbit species, our more abundant white-tailed species does not thrive as well as the black-tailed around cultivated sites.
Translation: When humans change prairie ecosystems to urban areas or predominately crops some species don’t handle the change well.
That would explain the long downhill population trend of white-tailed jackrabbits. But why do their numbers seem to be increasing now?