| ||||
|
|
Nevada bighorn sheep continue to die
RENO, Nev. (AP)--Wildlife experts say about a third of Nevada's largest herd of California bighorn sheep may have died of a respiratory ailment that began claiming animals last winter.
Another dead bighorn was found June 6 in the Santa Rosa Mountains north of Winnemucca, leading scientists to suspect the die-off is not over.
"It's not a good sign," Mike Dobel, a game biologist with the Nevada Department of Wildlife, told the Reno Gazette-Journal.
"We were hoping that the event would have exhausted itself. It appears we still have something going on."
The latest animal showed evidence of pneumonia and lung damage--the same fatal condition experts believe already has reduced the Santa Rosa herd from about 290 sheep in 2003 to 190 today.
Experts are particularly concerned because the Santa Rosa herd represents one of the biggest success stories in Nevada's efforts to re-establish bighorn sheep, which nearly disappeared across the state after the arrival of European settlers and disease-carrying domestic sheep.
Twelve California bighorns were introduced in the Santa Rosa Mountains in 1978, and by last year the population approached 300.
Concern arose just before Christmas when state officials started hearing stories of hunters finding sick and dead bighorns.
Samples taken from dead and healthy bighorn provide some clues but few solid answers as to the source of the problem.
Although domestic sheep were seen in the area before the first dead bighorns were discovered, there's no evidence directly linking those animals to the infection, experts said.
"We can't say that it did, we can't say that it didn't," said Alton Ward, a microbiologist and retired professor with the University of Idaho.
Ward prepared a report on the die-off recently submitted to the Nevada wildlife agency.
Whatever the source of infection, what does appear clear is that the Santa Rosa bighorns were substantially weakened by a variety of factors last winter, Ward said.
Prolonged drought reduced forage and lack of food might have weakened the herd, Ward noted in his report. Twice-normal snowfall in December further could have weakened the animals by causing them to burn more energy pushing through deep snow.
Parasites, while common in bighorn, could have further diminished nutritional intake and made the bighorns more susceptible to infection resulting in the pneumonia that killed them.
"Those factors could have all contributed," Ward said.
The combination might have resulted in a biological "perfect storm" that combined to produce the die-off, agreed Rick Furman, a Reno veterinarian and vice president of Nevada Bighorns Unlimited.
"It was probably the additive effects of multiple factors," Furman said. "What we're suspecting is that this population of sheep was debilitated and that made them susceptible to viral infections."
What's particularly worrying, Furman said, is that the die-off appears to be continuing. Typically they are over in a month or less, he said.
"This happens, but it's heartbreaking that it happens," he said.
Date: 6/24/04
Copyright 1995-2008. High Plains Publishers, Inc. All rights reserved. Any republishing of these pages, including electronic reproduction of the editorial archives or classified advertising, is strictly prohibited. If you have questions or comments you can reach us at High Plains Journal 1500 E. Wyatt Earp Blvd., P.O. Box 760, Dodge City, KS 67801 or call 1-800-452-7171. Email: webmaster@hpj.com
 
| |||||||||||||||||||||
