by Mike Thompson
Montana Fish, Wildlife & Parks
Seeley Swan Pathfinder
October 1, 1998
This summer has probably had the same biological effect on black bears as the harsh winter of 1997 had on elk and deer.
FWP's Bob Henderson found himself nodding along as he heard a biologist from Idaho Fish and Game offer that observation on this year's bear situation. Unless you've been hibernating, you're already aware that bears seem to be everywhere this year. What might be catching you by surprise is the idea that the hungry bears on your porches this fall may have a lot in common with the hungry deer that were on your porches two winters ago.
And, just like the deer that came to you in a desperate attempt to escape winter, so will an unusually high number of begging bears eventually succumb to the lingering effects of this summer's food shortage. It is certainly reasonable to expect that our black bear populations are in the midst of a decline that will likely continue through next year, at least.
Quite possibly, there will be fewer black bears next year than there are this year, whether FWP liberalizes hunting regulations or whether we stand pat.
What information would support this view?
Research has shown that nutrition is the single most important factor determining reproductive success in black bears. Bears are so in tune with their food supply that the fertilized egg in a pregnant female will not implant in the uterus if the bear is not in satisfactory physical condition by fall. Mature females breed every spring or summer in years when they're not nursing, but they do so with an unconditional guarantee. "Try your fertilized egg for 90, or even 120 days, and if you don't agree that a growing fetus is the best thing that could happen to you this fall, send the undeveloped egg back for a full refund."
Although the reproductive process in bears differs from deer and elk, the ultimate result of harsh environmental conditions on the coming crop of newborns is much the same. Just as we lost most of our elk calves and deer fawns before they were born during the harsh winter of 1997, we can also expect to see very few bear cubs next spring.
We can also expect exceptionally high losses of cubs that are already among us this year. Food shortages in bear country mean exceptionally hard times for those in the bear population that are least experienced and skilled in finding food, and for those who need high quality forage for early skeletal growth. Those are cubs.
Based on the number of lone cubs we're finding in back yards and barbecues, some biologists are wondering if more females are abandoning their cubs entirely, due to extreme nutritional stress. You would also expect higher than normal rates of predation by adult males on cubs and sub-adult bears due to unusual nutritional stress felt by males and a lack of protection offered by maternal females for their young.
That makes two (at least) years worth of cubs lost to the harsh conditions of this summer and fall.
On top of this substantial interruption in reproduction, consider the unusual losses of older bears this year to all sorts of demises associated with human conflicts. Like deer and elk in the winter of 1997, bears re responding to their problems by gathering around highways, and FWP is handling an exceptional number of road-killed bears. It's also unlikely that trapped, drugged and transplanted bears have bounced back very well in unfamiliar habitats under the difficult conditions they face this year. And, damage to beehives often leads to the destruction of offending bears.
With bears congregated at low elevations in people's back yards, the only thing preventing an exceptionally high harvest of bears this fall will be limitations in finding a safe situation to fire a rifle.
So-called problem bears normally make up a relatively small proportion of the overall bear population. But in years like this, a higher proportion of the entire population is subjected to the stresses and hazards of living with people, due to the nutritional shortages faced by the population at large. Substantial population impacts may be felt during such times when a large proportion of the bear population is vulnerable to hunting and control actions.
FWP's response to the deer population decline caused by the harsh winter of 1997 was to reduce hunting pressure and allow populations to rebuild. In most hunting seasons, many bears live in refuges from all but the most dedicated bear hunters, behind locked gates and in back-country areas, so additional restrictions in hunting regulations may not be necessary to conserve core bear populations. On the other hand, it may be difficult to justify any increase in hunting pressure with biological information.
As was the case for deer and elk after the harsh winter of 1997, it will be interesting to follow events in the aftermath of this harsh summer and fall for black bears. And, you can add "Game Range Ramblings" to the list of autumn casualties. It's not road-killed, bit it's tired and needs a short break. I'll talk to you again in a couple weeks or so.