Wily coyote outgunned by bigger canine cousin
YELLOWSTONE NATIONAL PARK, Wyoming (Reuters) -- Wily coyote has run into a spot of trouble, at least in Yellowstone National Park, where the canine once reigned supreme, until his bigger cousin the wolf came on the scene with great fanfare in 1995.
Things have not been the same since.
When 31 gray wolves were released in Yellowstone in 1995 and 1996, all the attention was on the great predators: Would they thrive? Would legal challenges from ranchers groups fearing the loss of young livestock send them packing?
Now the legal challenge is settled and the wolves have done just fine, expanding their numbers to 168 in as many as 16 packs. But the biological effects are reverberating throughout the Yellowstone ecosystem. Coyotes, long overabundant because of no competition from wolves, have been hit the hardest, with populations in some parts of the park sliced in half.
"Certainly the species that is going to be impacted the most in the short term, which I call the first 10 years, is the coyote," said Bob Crabtree, founder and science director of Yellowstone Ecosystem Studies, a private nonprofit research group that has studied coyotes there for more than a decade.
"You might think a 50 percent reduction is big, and it is, but remember, coyote populations likely increased in the 1930s after wolves were extirpated," Crabtree said.
Since they were reintroduced in 1995, the wolves have already expanded beyond the boundaries of the 2.2 million acre park, just as they have taken over territory formerly occupied by their smaller cousins.
No longer the park's top dog, coyote populations in an intensively studied portion of extreme northern Yellowstone have dropped by about 50 percent, to between 250 and 300, since the wolves returned, researchers say.
In the Lamar Valley east of park headquarters in Mammoth Hot Springs, coyote packs once averaging five animals each now number only two or three. Coyote territories in northern Yellowstone have shrunk, with the wolf now dominating open grassland in the central Lamar Valley, and many coyotes have been outright killed by wolves protecting their elk carcasses.
Wolves attract packs of tourists
Visitors flock to the Lamar Valley to see the Druid Peak wolves, which scientists call the most visible and studied wolf pack in the world. More than 3 million people a year visit Yellowstone -- the world's first national park -- and officials say the wolves are quickly becoming one of the park's top draws, often causing traffic problems when a pack is in view.
Wolf watchers love to catch sight of them hunting and feeding, but a coyote hanging around for a look and maybe a nibble at leftover elk carcass can get into trouble.
Once the wolf pack has gorged itself, the animals nap and digest their meal; raptors and other animals then feast on the remains. But it is a different story when it comes to coyotes: Wolves are territorial and much faster than coyotes, even with a belly full of meat, and they have been known to deal the ultimate blow to many a coyote trying to lunch on leftovers.
Before the wolves returned, the most common cause of coyote deaths was traffic, Dave Bopp of Yellowstone Ecosystem Studies said. "Now that the wolves are here, they kill most of the coyotes," he said.
Crabtree said the coyote population has not decreased evenly. In core areas of wolf activity, the reduction might be 80-90 percent, while less-used areas within wolf territory have seen a 30-50 percent reduction. "Between wolf territories, coyote populations are doing just fine and may even in some cases have benefited," he said.
Bopp said coyotes have apparently learned that roads represent a safe haven from wolves, who are extremely shy and will do anything to avoid human contact.
Ripples in the food chain
Park Spokeswoman Marsha Karle said some visitors, despite warnings, have been tempted to make friends with the coyotes, which often show little fear of people. But feeding animals, as well as calling to animals, is banned in the park, she said.
"You start getting these beggar coyotes ... they hang around the roads more and they get hit by cars," Karle said. "They should be eating things that it is natural for them to eat, rather than Twinkies."
Coyotes feed largely on rodents, so fewer coyotes should mean more rodents. Theoretically, that means more food for another canine cousin, the fox, as well as owls and hawks.
As the presence of the wolf ripples through the food chain, canine populations should come into healthier proportions, according John Varley, Yellowstone's chief scientist and director of the Yellowstone Center for Resources.
The fox already appears to be prospering, Varley said, adding, "You drop the pebble in the pool and you watch the ripples, and they go out and go out and go out, and they seemingly last forever."
Copyright 2001 Reuters. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
|Back to the top|