Bear den surveys reflect influence of summer drought

WALDRON — Last summer’s drought may have some lingering impact on
Arkansas’s black bear reproduction, but there’s no immediate cause for
alarm, according to Myron Means, the Arkansas Game and Fish Commission’s
large carnivore program coordinator.

Each year Means works with biologists and technicians from the AGFC’s
Wildlife Management and Research divisions during February and March to
visit female bears at their dens and evaluate their condition and the
condition of their cubs to identify trends that may impact the entire

“We try to maintain about 60 female bears with radio collars throughout the
state to help us with our monitoring work,” Means said. “Of those, about
half will be with yearlings and the other half will have cubs with them in
their dens.”

Means explains that female bears typically take two years to have and raise
their young. During the first winter, the sows will have their cubs with
them and allow them to nurse. Those cubs will stay with the mother
throughout the year and through the next winter “learning to be bears.”
Upon emerging from their second denning cycle, the yearlings will be pushed
from the mother’s home.

“She’ll actually let her female yearlings stay in a part of her home range,
but she’ll push the males out,” Means said. “That does two things:it
ensures that her female cubs have a good place that provides adequate food
and resources, and it prevents issues that can arise from inbreeding. It’s
one of those ways Mother Nature works that’s just really interesting.”

Typically, a female black bear is sexually mature at 3-5 years old.
Arkansas bears tend to begin reproducing at age 3 or 4. They can have cubs
until they are around 20 years old. That gives them 16 years of opportunity
to reproduce.

“But with an every-other-year cycle, we’re really only looking at raising
young eight times at most,” Means said. “With the average litter size being
two cubs, a female bear will produce about 16 cubs if she survives
throughout a bear’s typical natural lifespan.”

This fascinating two-year reproductive cycle also means biologists must
keep constant tabs on the population, as it is much slower than other game
species in Arkansas.

“We have much fewer bears than deer and other game, and they reproduce much
more slowly, so we really want to identify trends as soon as possible,”
Means said. “That means we really need to keep a close eye on reproduction
each year. If you overharvest bears, it can take a long time to recover. We
have different regulations and season frameworks that can help prevent that
if we have this annual data.”

The process of bear den monitoring actually begins in
summer when biologists and technicians across Arkansas’s bear range set and
monitor snare traps to catch bears they are seeing on game cameras and
during their work on wildlife management areas. They sedate the bears, take
their measurements and outfit them with radio collars. Each collar has a
signal emitter that biologists can later use to locate the bear using
special equipment. It can take days of driving and hiking to discover
exactly where a female bear has decided to make her den for the winter.

“Our south Arkansas bears were given GPS collars, which give locations a
bit easier,” Means said. “Those are much more expensive, so the majority of our collared bears still use the radio-signal version for now.”

Biologists look for the dens in late winter and have a list of bears that
should be with cubs to visit. They will quietly approach the mother bear
and again sedate her using a special mix of chemicals.

“We’re actually working with researchers from Texas testing a new drug for
the trips,” Means said. “The previous drugs we used were highly monitored
by regulatory agencies, and this one should be safer for the bears. It has
the ability to be reversed. This lets the mother bear get back to the
business of raising her cub as soon as we’re gone.”

Despite popular belief, Means says bears aren’t true hibernators. Many
animals like groundhogs can lower their body processes – for example,
pulse rates and breathing rates – to the point they are catatonic. It can
take several hours for a hibernating animal to rouse from this state. This
is not the case with a mother bear.

“She’ll lower her heart rate and breathing rate as well as other bodily
functions during the winter denning cycle, but not to that catatonic
state,” Means said. “If she sees, hears or smells an intruder, she can
instantly respond. Just about every bear we approach in our research will
be awake when we arrive to sedate her.

So far this year the bears in the Ozarks and Ouachitas have shown
reproductive rates at roughly 45 percent of what they typically record.
While this might be cause for concern, Means says the bear population is
still very healthy and should be able to withstand one poor year of

“We’re seeing sows without cubs and sows with only one cub,” Means said.
“The female bears and the cubs produced are in good condition, there are
just less cubs this year. “That’s normally an indication of poor habitat
quality during the first few months of the bear’s reproductive cycle.”

Means says that although breeding takes place in spring, the bear’s body
can reject the pregnancy if conditions are not good.

Last year’s drought hit the berry crop hard in the northern half of the
state, reducing the amount of wild blackberries and wild cherries these
female bears would normally have been eating. But the acorn crop was good,
so those bears who did have cubs recovered quickly and are showing very
good health. The drought conditions weren’t as bad in the southern half of
the state, and we had a really good berry crop in the Gulf Coastal Plain.
Those bears continue to show good reproduction.”