Monday, November 26, 2012

Grizzly Bear in Missouri?

Grizzly Bear- Wikimedia
So what was the Ozark's top or apex predator before wolves?  How about the grizzly bear, Ursus arctos horribilis.   The presence of grizzlies in Missouri was a little hard to swallow (sorry)  when Steve Craig first presented the idea to me, but he made a solid case for their presence on the western edge as described below.

The current range of grizzlies is shown on the dark green portion of the map.  Recalling that the glaciers were retreating around 12,000 years ago and the climate, flora and fauna in the Ozarks was far different, probably more like their current range of Montana and Canada.  The grizzly faced adaptation to "climate change" just as we do now.

Grizzly range- then and now- Wikimedia
Within historical times there are records of grizzly bears on the Great Plains.   The following comes from the Mammals of Kansas:
"The grizzly bear was probably extirpated in Kansas by the middle 1800's. Its original abundance in Kansas is unknown, but it was reported to have been common, and to have depended heavily on the great herds of bison for food."
I have been unable to find any mention of grizzly bears in Missouri historical documents.  They certainly occurred on the Great Plains which extend into the far western edge of Missouri.   Whether they ever prowled the deep river valleys of the Ozarks is open to conjecture.

And what did the grizzly eat?  Anything it wanted to- after all, who can refuse a 300-800 # omnivore.  Wolves coexist with grizzlies but while still the top dog, they arguably share the honors as the apex predator.  Wolves and grizzlies generally share their territory peacefully but on rare occasion one may kill the other.

The story of the reintroduction of wolves in Yellowstone Park is a great example of the influence of an apex predator on the diversity of an ecosystem.  The wolf's primary prey is the elk.  Wolves have reduced the elk, decreasing the browsing pressure on riparian plants.  This in turn has led to expanded populations of beaver, moose and other species.

Surprisingly, even the vulnerable grizzly population benefited from the wolf reintroduction.  Grizzlies frequently eat wolf kills, increasing their food supply before hibernation and in the critical period when they come out of hibernation with their hungry cubs.    Even black bears, coyotes, eagles and ravens will eat the remains of a wolf kill.

Grizzly bears therefore are a keystone species, shaping the whole ecosystem.  The salmon they harvest replenishes the soil, both as the uneaten salmon deposited on the ground and by recycling nutrients as feces.  More on this subject can be found in the Wikipedia article on keystone species.

So what is the top predator of the Ozarks?  It depends on when you ask the question.  Excluding humans it may be the coyote.  But as Wiley Coyote repeatedly learned from the Road Runner in the cartoons, he better watch out.

On the lighter side, you can see what a grizzly can do to a Toyota SUV at carbuzz.com.