At their peak, snowshoe hares become forces of nature
This year, a biological force of nature bigger than a bull moose lives in the boreal forests of North America. It’s most visible around dawn and twilight. That’s when the biggest animals of the northern woods – by total species weight – come out to hop around and nibble on twigs and grass.
Snowshoe hares are mid-sized herbivores that weigh 3 to 4 pounds and are named for their furry hind feet that help them travel through deep snow.
They’re not nearly as iconic as Alaska’s moose, bears or wolves, but Alaska’s snowshoe hares play a disproportionately important role in the food chain around Fairbanks and throughout the boreal forest across Canada and in the northern Lower 48 states.
When the snowshoe hare population does well, it does very well and transforms the landscape. Hares breed quickly, with females producing 15 or more young in a year. About every 10 years, snowshoe hares reach particularly high population densities.
In the Fairbanks area, the snowshoe hare wave is building but has not yet crested. The last year the Fairbanks area hit the snowshoe hare peak was 2009. Roadside surveys show hare numbers are growing still and are likely to peak in a year or two, said Cameron Carroll, small game biologist at the Alaska Department of Fish and Game office in Fairbanks.
At their peak, hares in Alaska can reach a density of 600 per square mile. That’s about half the density of humans in America’s most densely populated state, New Jersey. At the snowshoe hare peak, the weight of all the hares in an area easily exceeds the weight of moose in the area, despite the fact moose weigh several hundred times more.
Hares and the food chain
Hunters and trappers have long observed the relationship between snowshoe hares and other creatures. The connection between snowshoe hares and lynx is especially strong and is visible in the regular spikes of lynx skin availability in fur trade records. The wildcats are especially dependent on hares and their populations regularly drop off a year or two after the hares decline.
Other connections have been observed between hares and animals such as upland birds, squirrels and raptors. One often-cited study of Kluane Lake tracked populations of hares and other animals in the 1980s and 90s. Kluane Lake is between Fairbanks and Whitehorse, Yukon, along the Alaska Highway. The study concluded that in addition to lynx, populations of predators such as coyotes, goshawks and great-horned owls correlated with hares. Among prey species, the study found willow ptarmigan, spruce grouse and Arctic ground squirrel species matched the population swings of snowshoe hares.
The Kluane Lake study, published in the Danish journal Oikos in 1995, concluded the snowshoe hare was a key distinguishing feature of northern North America’s ecology as compared to northern Europe, where life revolves around vole populations.
Randy Zarnke, president of the Alaska Trappers Association, has been trapping in Alaska through the past four snowshoe hare peaks. Trappers have long observed the snowshoe hare cycle isn’t the same everywhere, he said. This year, the snowshoe hare spike appears to have arrived early in the Eastern Interior. For the past few seasons, trappers around Tok have been catching lynx, but lynx haven’t arrived in Fairbanks, he said.
“The trappers in the Fairbanks area have been waiting with bated breath,” he said. “We even heard that straight north of here there were quite a few lynx around and they just didn’t seem to have made it here. So the expectation in the trapping community is that we will start to see them this season.”
The hare cycle connection to lynx is particularly obvious to trappers, Zarnke said. Other animals, such as coyotes and upland birds, are more random and don’t have an obvious connection to hares, but to a lesser extent, he’s observed a correlation between hares and fox, he said.
While the 10-year cycle between hare population peaks is fairly regular, the magnitude of the peak can range dramatically, Zarnke said. When he first moved to Alaska, he heard stories about hunters easily shooting a half dozen hares in 10 minutes of hunting. But he wasn’t particularly impressed by the first snowshoe hare peak he saw in the 1970s.
The next peak was different.
“The second time, when the cycle came back around, there was a real high peak,” he said. “And I remember just having a big smile on my face saying ‘Oh, this is what they’ve been talking about.’ It was good catching the lynx, but it was equally as interesting to experience that huge change, just being part of it.”
Living with snowshoe hares
Alaska’s wildlife managers regulate small game hunting liberally with long seasons and high bag limits. In most of Alaska, including the Fairbanks area, no bag limit exists and the season is open year-round for snowshoe hare.
Alaska’s hare harvest isn’t well known because, unlike for large game hunts, hunters don’t have to record hare harvests. The most recent study concluded hunters in 2013 harvested roughly 23,000 snowshoe hares, based on numbers from hunters who participated in surveys. Hunters also took roughly 7,500 Alaska hares, a significantly larger hare found in western Alaska. The year 2013 was a relatively low population year for hares because of a population crash after the 2009 peak.
For gardeners, the growing hare population can mean more pests to protect against. Snowshoe hares have a reputation for liking vegetables and flowers such as tulips, said Julie Riley, horticulture agent at the University of Alaska Fairbanks Cooperative Extension Service. However, this summer Riley said she has received many calls about voles causing problems in gardens and none about hares.
At her own home, she’s seen several hares within her fenced garden but hasn’t had problems from them, she said. The Cooperative Extension office has resources for how to build garden fences that will keep hares and other pests out.
As winter approaches, hares turn to eating woody materials and can kill ornamental trees by eating bark around the base, Riley said. Stems that have been gnawed on by hares have distinct 45-degree angle chew marks. People who want to protect favorite trees can do so by putting a ring of heavy-duty wire mesh near the bases, she said.
The rise in hares also can bring an increase of tularemia cases. Tularemia is a bacterial infection that often infects hares and can spread to humans, cats and dogs. Two years ago, a North Pole man was sickened by tularemia after skinning an infected hare. In humans, tularemia can cause fever, chills and headaches. It can be fatal.
This summer, two cats in the North Pole area died from the infection, said Laurie Boeck, wildlife biologist at the Alaska Department of Fish and Game. Infected hares become lethargic and can be caught easily by dogs and cats. A dog or cat that has become ill after spending time alone outside should be taken to a veterinarian, Boeck said. Animal owners who encounter dead hares should bury them while wearing gloves, or dispose of them somewhere where pets won’t get the carcasses.
Hunters should use gloves when handling hares. If the hares have inflamed livers and spleens, it’s a sign they are infected.