The Rise and Fall of the Snowshoe Hare
- The Rise and Fall of the Snowshoe Hare
Decline has predators on the prowl
By TIM MOWRY
You don't have to tell Randy Zarnke that the snowshoe hare population has
crashed in the Interior. He sees it every weekend when he walks his trapline
north of Fairbanks on a pair of snowshoes.
"Last year when I walked my line you never were out of sight of rabbit
tracks," said Zarnke, a part-time trapper and full-time wildlife biologist
for the Alaska Department of Fish and Game. "Now you only see a few."
It happens every 10 years or so, almost like clockwork.
The snowshoe hare population grows so big, so fast, that the food supply
can't keep up. The hares basically starve themselves out because they
reproduce too fast.
"When they get to the top of their cycle like they did a couple years ago,
the majority of high-quality forage is gone," said Zarnke.
The lack of good food causes the reproductive rate of female hares to
plummet and the population begins to decline. Predators, especially lynx,
force it farther down, into what biologists refer to as a "predator pit,"
the point where the population can't keep up with the demand of predators. A
year or two later, when there are no more hares to eat, it's the predators'
turn to crash.
"Hares crash and generally a year or two later lynx hit the bottom," said
Fish and Game furbearer biologist Mark McNay. "Last year the number of hares
was down and this year it's down even more. We're getting down toward the
There is no predator-prey relationship more closely tied than that of the
snowshoe hare and lynx. When the hare population peaks, so does the lynx
population. When the number of hares drops, so do the number of lynx.
"In the 23 or 24 years I've been here we've never had a hare population go
this high and we've never had a lynx population as high as it's been the
last two or three years," Zarnke said.
While lynx sightings are usually rare, Fish and Game has received several
reports of lynx over the past few months as the stealthy cats get bolder and
search farther for food.
"We've been getting lots and lots of reports of lynx in places where we're
not used to seeing them," said Fish and Game's Cathie Harms. "They're having
to work a lot harder right now to find food."
While snowshoe hares are not the sole food source for lynx--the cats also
eat grouse or ptarmigan and have even been known to kill young caribou and
Dall sheep on occasion--they are the primary one. During lows in the
snowshoe hare population, lynx are hardpressed to find enough food to eat.
Many of them don't.
"Those lynx that survive have varied diets that include things like red
squirrels, grouse and microtines," McNay said. "Those that can do it
effectively are the ones that make it through the cycle."
The increase in lynx sightings doesn't surprise wildlife biologists. With
fewer snowshoe hares, lynx are looking for alternative food sources wherever
they can find them.
"When predators are in dire straits they'll do things they normally wouldn't
do," said Zarnke.
Judging from the number of tracks they saw prior to the season, trappers
thought this would be another big lynx year but that hasn't been the case,
"A lot of us said, 'Geez, there's lynx tracks everywhere; it's going to be
another great year for lynx,"' Zarnke said. "We're not seeing that. I think
what happened is there were fewer lynx out there but they were running
around more than the year before because they were looking for something to
One trapper told Zarnke he caught only two lynx this year on his trapline in
the Yukon Flats after taking 26 a year ago.
Lynx aren't the only predators who may have growling stomachs because of the
low number of snowshoe hares, either.
A great-horned owl has been terrorizing one neighborhood in the Goldstream
Valley, said Harms.
The owl has attempted to make off with several small dogs and has been more
than a little brazen. One dog owner kicked the owl twice to get it to let go
of her dog.
Another person was walking a puppy on a leash and the owls swooped down and
grabbed the dog. It didn't drop the puppy until the leash got wrapped around
the owner's leg.
"It goes right down the line, from lynx to fox to coyotes to birds of prey,"
said biologist Jeff Selinger. "They all benefitted from the hare high. Now
that the hares have gone away they're looking for something to eat."