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Raven population growth creates headaches in Nevada

Henry Brean
A raven, center left, prepares to take off from a rock pile as other types of birds fly around at the Apex Landfill north of Las Vegas Friday, Feb. 2, 2013. Ravens pose a growing problem for ranchers, wildlife managers and two well-known species struggling to survive. The clever and adaptable black bird preys on both the desert tortoise and the sage grouse, the former already protected under the Endangered Species Act, the latter on track to join it. Efforts to save those species could mean death for more ravens. Already, the birds are killed by the thousands in Nevada each year. Some people think far more ravens need to die. Others believe the wholesale murder of them won't accomplish anything - and it might just make things worse. (AP Photo/Las Vegas Review-Journal/John Locherl)
John Locher
Ravens stand on gas pipes as other birds fly by at the Apex Landfill north of Las Vegas Friday, Feb. 2, 2013. Ravens pose a growing problem for ranchers, wildlife managers and two well-known species struggling to survive. The clever and adaptable black bird preys on both the desert tortoise and the sage grouse, the former already protected under the Endangered Species Act, the latter on track to join it. Efforts to save those species could mean death for more ravens. Already, the birds are killed by the thousands in Nevada each year. Some people think far more ravens need to die. Others believe the wholesale murder of them won't accomplish anything - and it might just make things worse. (AP Photo/Las Vegas Review-Journal/John Locherl)
John Locher

Nevermind the Super Bowl team from Baltimore.

In Nevada, real ravens pose a growing problem for ranchers, wildlife managers and two well-known species struggling to survive.

The clever and adaptable black bird preys on both the desert tortoise and the sage grouse — the former already protected under the Endangered Species Act, the latter on track to join it.

Efforts to save those species could mean death for more ravens. Already, the birds are killed by the thousands in Nevada each year.

Some people think far more ravens need to die. Others believe the wholesale murder of them won't accomplish anything — and it might just make things worse.

But the raven isn't waiting around to learn its fate. It just keeps reproducing, learning new things and expanding its range.

By some estimates, raven populations nationwide have grown by 300 percent in the past 40 years. In Nevada, the increase is thought to be more like 600 percent.

A PROBLEM WITH HUMANS

The raven succeeds on the spoils of our success. It feeds on our garbage, hunts from our transmission towers and follows our highways to new territory, dining on roadkill along the way.

"We're literally paving the way for ravens to move farther and farther into the desert," Jason Jones, a herpetologist with the Nevada Department of Wildlife, told the Las Vegas Review-Journal (http://bit.ly/VvUjoU).

Common ravens grow to about 25 inches in length and weigh more than 2 pounds. They can live for more than 20 years and survive almost anywhere.

"You find them in Death Valley in the summer and at Prudhoe Bay, Alaska, in the winter," said John Hiatt, longtime conservation chairman for the Red Rock Audubon Society. "They're everywhere there is something to eat."

They're also among the smartest birds around. They solve puzzles, avoid threats and exhibit behavior that resembles play.

Shawn Espinosa, a staff biologist for the Nevada Department of Wildlife, said we should all be glad the birds don't have opposable thumbs. "They might rule the world," he said with a laugh.

KILLING TO CONTINUE

Almost 20,000 common ravens have been legally killed across Nevada in the past 12 years, according to state figures.

Last year alone, the Department of Wildlife killed 1,997 ravens, three birds shy of the limit set by its U.S. Fish and Wildlife Service permit.

The raven, as it turns out, is a protected species as well. It falls under the Migratory Bird Treaty Act of 1918, which covers more than 80 percent of birds native to the United States. For the time being, state wildlife officials plan to keep killing as many ravens as the law will allow, though they acknowledge that such efforts might well be futile.

There is some research that suggests killing ravens could increase their concentrations — that when a mated pair is killed, two pairs of ravens will take over the open territory, effectively doubling the number of beaks to feed. Even so, the state has spent almost $150,000 to poison 6,850 ravens in 10 Nevada counties since 2007.

A FIELD 'BLACK WITH CROWS'

Hank Vogler has been running livestock in White Pine County for almost 30 years. His spread in Spring Valley, in the heart of sage grouse country, is home to more than 6,000 sheep.

It's also a magnet for ravens, which foul his water troughs, steal food from his rams and kill up to 100 of his lambs each year by pecking out their eyes and tearing at their umbilical cords.

"Let me go to the window," Vogler said by phone one recent Thursday. "Yep. Out where the rams were fed this morning, it's absolutely black with crows."

He can go out and blast away at them with a shotgun, but they're smart enough to keep their distance. If they see him with a gun, they will just wait for him to leave and go back to stealing feed.

As far as he is concerned, killing ravens has proven ineffective only because wildlife officials haven't killed enough of them yet.

"Do I want to see every crow on Earth, every raven, die? No," Vogler said. "But do we need 600 percent more of them than we did before? No."

He is convinced that if the government would declare open season on ravens, there would be no need to add the sage grouse to the endangered species list. But he is equally convinced that some people want the sage grouse listed no matter what. That will give them the excuse they need to end livestock grazing on federal land, he said.

"Like they did with logging and the spotted owls. That's the endgame. Their perfect utopian world can't exist until you get everyone off government land."

CIRCLING FOR SOLUTIONS

Ted Koch leads the U.S. Fish and Wildlife Service in Nevada. He said ravens do pose a threat to sage grouse, but habitat loss is a far bigger factor in the bird's decline.

Reduce the sagebrush cover and damage the "understory" of native grasses, and you leave grouse with little to eat and nowhere to hide from predators.

"We're much more concerned about the fact that 822 acres per day of habitat was lost to wildfire in 2012," Koch said. "You could declare Nevada a raven-free zone, but if you continue to lose 822 acres a day, that's not going to make any difference."

Ravens seem to pose a bigger threat to Nevada's state reptile. For the first five or six years of life, tortoises have a shell soft enough to peck through, and the birds are prolific hunters.

Espinosa said that if you walk along one of the big transmission corridors that cross the Mojave Desert from Hoover Dam, "a good proportion of those towers will have a desert tortoise carapace under them."

Koch said there are several nonlethal things people can do to control ravens. They include limiting the birds' access to garbage dumps; quickly clearing away roadkill; making towers and power poles harder for ravens to hunt from; and building fewer such man-made perches in areas where sage grouse and tortoise live.

Killing more ravens is at the bottom of the list, Koch said, but it is on the list.

As a bird lover, Hiatt can't help but feel bad for the raven. But managing the environment is about making choices, "and there is no danger of ravens becoming an endangered species," the Audubon Society member said.

"If it wasn't for people providing all this opportunity for an opportunistic bird, we wouldn't have this problem," Hiatt said. "It's a man-made problem. Now we have to deal with it."

 


HENRY BREAN
Las Vegas Review-Journal