Biologist explains run on big Maine bears

Over the first two weeks of this year’s bear-hunting seasons, a number of large bears have been shot by hunters here in Maine.

Matt Knox of Pennsylvania (left) and guide Steve Monroe of Grand Slam Guide Service in Shirley pose with Knox’s state record 699-pound bear. (Photo courtesy of John Lonergan)

Indiana hunter Richard Paro went home with a 600-pounder that he shot in Township 39. Ben Cottrell of New York bagged a 522-pounder while hunting in New Canada. And Matt Knox of Pennsylvania (with help from guide Steve Monroe of Grand Slam Guide Service in Shirley) set a Maine record with the 699-pound black bear that he shot in Greenville Junction.

All are big specimens — once-in-a-lifetime bears for the lucky hunters — and all fell within a two-week span.

The obvious questions: What’s going on here? Is the recent run on big bears due to some underlying conditions that exist in the Maine woods?

The answer to the second question, according to Department of Inland Fisheries and Wildlife biologist Randy Cross, is a resounding “yes.”

His explanation, however, might not make much sense at first.

Cross’s theory: Bears are getting big (and making themselves available to hunters) because natural food isn’t as abundant as it is most years.

“[It makes sense] to me, but I understand it is counterintuitive to say the bears are fat because the food resource is particularly low this year,” Cross said in an email. “So it requires more [explaning].”

Cross, who has been studying Maine bears for more than 30 years, said a similar situation arose in 1995, when a very good year for natural food was followed by a very poor one. During poor years, those bears (which fared well in dens the previous year and emerged healthy and comparatively heavy, because food was so plentiful) have to work harder to find the food they’re seeking.

And when that happens, Cross has learned that the bears will essentially give up their quests for nourishment much earlier in the year, and head to their dens earlier.

In order to do that, they embark on a prolonged period of non-stop feeding, which biologists call “hyperphagia,” in order to pack on as much weight as possible before their long winter of inactivity.

“Many years, the bulk of the bait harvest occurs (during the first two weeks of bait season) before bears are in their heaviest binge feeding,” Cross wrote.

And during most of those years, the bears that are harvested by hunters will not have begun truly packing on the pounds. This year, that’s not the case.

Cross said he expects bears to head to their dens very early this year, and because of that, they’re already feeding voraciously. In addition, that sense of urgency makes bears more vulnerable to bait. In fact, even the more experienced, older, larger bears become more vulnerable. Cross said those 12- to 18-year-old bears have largely learned to avoid daylight feeding at bait. This year, that’s not the case nearly as often.

Which brings us back to 1995, when Cross said a similar situation arose.

“In 1995 the nuisance levels were beyond what anyone had seen up to that time (and maybe since). Bears were on the nightly news regularly,” he wrote.

Cub survival was poor — “miserable” according to Cross — after bears went into their dens in 1995. Cross said just 40 percent of cubs survived overall, with about 33 percent surviving in the state’s northern study area.

“The few yearlings that were still alive in our northern study area averaged only 23.5 pounds that winter,” Cross wrote. “For reference, yearlings her averaged 64 pounds after the strong food year in 2006, and 61.8 pounds last winter.”

The good news: Cross doesn’t think a single year will have long-lasting effects on the state’s bear population.

“Bears quickly bounce back from a poor food year like this, causing relatively insignificant lasting effects on the population,” Cross wrote. “However, if we see two or three years in a decade [with particularly poor food production] that would result in a significant change in recruitment [the addition of new bears to the population], age of first reproduction and other parameters that would impact population dynamics in the end.”

Cross said that the most recent decade was marked by conditions much different than those that existed this year.

“In fact it has been the richest 10-year period in terms of bear food in the 30-year window that I have been looking through,” he said.

And Cross pointed out that there’s a natural ebb and flow when it comes to supplies of bear foods: Many bear-preferred berries or nuts just don’t produce bumper crops in consecutive years, and bears adapt to that.



John Holyoke

About John Holyoke

John Holyoke has been enjoying himself in Maine's great outdoors since he was a kid. Today, he's the Outdoors editor for the BDN, a job that allows him to meet up with Maine outdoors enthusiasts in their natural habitat. The stories he gathers provide fodder for his columns, and this blog.