12 February 2008

moose learn from bear, humans


…read all about it in the New York Times:

Grizzlies tend to avoid humans. In the part of Yellowstone that I’ve been studying this past decade, the Grand Teton National Park, grizzlies don’t go near the roads because they know that’s where the humans and cars are.

I collar and track moose as part of my wider research on prey-predator relationships. For the past 10 years, we’ve noticed that Grand Teton moose are, each year, moving about 375 feet closer to the roads when they are about to calve. We think they are doing it because they’ve figured out that the paved road is a bear-free zone where their newborns stand a better chance of survival. Up in Alaska, grizzly bears have been observed killing between 50 and 90 percent of the newborn moose population. We think that the Grand Teton moose have figured out a way to use humans as shields for their babies.

Q. Is this a new behavior for them?

A. It’s recent. Until the mid-1990s, the moose of the Yellowstone basin lived in a kind of moose paradise, without predators. The wolves had all been shot out about 70 years earlier. Grizzly bears were heavily hunted, and there were few of them. Without their traditional predators, Grand Teton moose were docile, naïve.

That all changed in the mid-1990s when the grizzlies rebounded because of a ban on their hunt and when wolves were reintroduced to the Yellowstone region. The first Grand Teton moose to encounter a wolf probably thought it was nothing more than a big coyote, which she didn’t fear. We reconstructed the interaction from tracks we found in the snow. From what we could see, the wolves just walked up to the moose and grabbed her 300 pound calf and ate it.

Grand Teton moose have learned a lot since then. Most of us think of moose as these dim lumbering Bullwinkles, but they figure things out. Today, if I were to play wolf calls over a loudspeaker to a herd in the park, they’d become vigilant — and they’d move away.

Q. Isn’t this just moose instinct at work?

A. No. They didn’t do it 15 years ago.

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