In boom, bust cycle of hare, future is moot

The trail was packed just deep enough to form a bit of a trench, and though the sides of that trench were by no means an impediment to an animal that can launch itself airborne nearly 10 feet at a bound, the hare was overcome by its fear. It sought not the best escape route, but the easiest.

Thus it remained caught in the beam of the light, running along in front for an inordinately long time, swerving wildly down the trail, it's eyes almost visibly enlarged in fright, before finally stumbling into a spot where the side of the trail ramped off into the woods. It was there the hair finally disappeared into the surrounding forest of spruce.

It was hard not to feel a little sorry for the poor, scared animal.

It was not a good night to be a hare at a time when it is not a good winter to be a hare.

The killers are everywhere in the country.

Along the trail on this day, there were fresh tracks of lynx, coyote and fox, and in the evening sky just before dark, a pair of goshawks were on the prowl overhead. They would roost in the darkness, but then the owls -- which have been filling the night air with their hooting -- would take over the hunt.

Beside the neighborhood trails, the dogs have been finding evidence of their deadly proficiency almost daily, the leg and some strips of fur from a snowshoe hare here, the feet of a snowshoe hare there.

That old belief about a lucky rabbit's foot? Don't believe it. It's lucky only for the foot.

The foot seems to be the only part of a snowshoe hare some predator doesn't want to eat, and with hare numbers now at or near a peak, there are a lot of predators.

This happens on about a decade-long cycle across much of North America. The last peak was 1997 to 1999, which would put us at or near the height of another one.

Judging from the hare living in my yard, a somewhat unusual occurrence over a couple of decades in Anchorage, I'd guess that if we're not already at the peak locally we're very close.

It will end shortly. The boom and bust of hare populations are among the best documented phenomenon in nature.

It was once thought to be linked to lynx numbers.

Lynx are a snowshoe hunting specialist, and trapping records from the Hudson Bay Company going back hundreds of years in northern Canada and Alaska show that as hare numbers increase so do the number of lynx until the latter reach a peak at which they were thought to have the consumptive power to collapse the entire system.

Only it isn't quite that simple.

Although lynx play a major role, Charles J. Krebs at the University of British Columbia and other Canadian scientists who've spent decades studying hares, have found the cycle involves predation by a wide variety of species -- even red squirrels get involved in killing and eating the young of hares -- along with a change in reproductive behavior on the part of the hares themselves.

As hare numbers go up, reproductive success, oddly enough, goes down.

Hares, like many of the prey animals at the base of the pyramid of life, can be prolific breeders.

They start young at only a year's age, and a female can have three or four litters averaging five leverets, as the young of hares are called, over the course of a summer.

At the peak of reproduction, one female hare can produce 16 to 18 young each year. But reproduction begins to falter even as the hare population is building toward its peak.

At times like now, when hares seem to be everywhere, reproductive rates may have dropped to half or less of their highest.

This was long theorized to be due to changes in food quality or abundance as mushrooming hare populations aggressively browsed forests. But that theory was proven wrong by the Canadian scientists early this century. They now theorize that the cause for the reproductive slow down might simply be stress.

Hares have so many predators chasing them so often at the peak of their cycle that they are too busy running for their lives, or preoccupied with running for their lives, that they don't or can't breed.

It is a dangerous life, that of the hare.

The snow-white fur of winter might make it easier to hide, but it is not like a claw-proof, fang-proof vest.

Not by a long shot.

Tracking of radio-collared hares found that at the peak of predator abundance, an individual hare has about a 30 percent chance of being caught, killed and eaten within a month.

Factor that over the many months of winter and, well, you get the idea.

Be thankful you're not a hare, because the world of the hare is full of other animals that want to kill and eat you even if they don't really need to.

That is the other interesting part of the study by Krebs and others. They found predators live in the moment, like many of us do, without any thought about the future.

Forget all that nonsense about the "balance of nature." It exists only as a see-saw driven by the prime directive of the wild which dictates that every animal strive to grow fat. When the eating is good, eat. This simple concept drives the lives of everything from voles to hares to coyotes to moose to bears.

When hares are abundant, the Canadian scientists observed, the kill rates for all predators were "well in excess of energy demands. Surplus killing seems to be a characteristic feature of these predators."

In simple terms, they kill more than they need, and if you're a lynx or a coyote it probably makes a certain sense. Putting on some extra fat to help get through the lean times likely just feels good.

Little do they know that they are, in the process, setting the stage for the serious decline of their own kind. But then, wild animals live for today, not tomorrow, and they give no thought to the future of their species.

We do, or at least we're supposed to. It is really about all that separates us from the other animals.

Find outdoors editor Craig Medred online at adn.com/contact/cmedred or call 257-4588.