Just thought I'd post this to make other folks aware of what's happening in Nevada.

Thursday, June 10, 2004
Copyright © Las Vegas Review-Journal

Officials worry about loss of bighorn sheep

Respiratory ailment has caused major die-off of herd in mountains of Northern Nevada

THE ASSOCIATED PRESS

RENO -- Wildlife experts say about one-third of Nevada's largest herd of California bighorn sheep might have died of a respiratory ailment that began claiming animals last winter.

Another dead bighorn was found Sunday 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 that experts believe already has reduced the Santa Rosa herd from about 290 sheep in 2003 to 190 today.

In Southern Nevada, state wildlife biologists are also suspicious that there might be disease-related problems with desert bighorn sheep.

They are monitoring a herd of desert bighorns in the Specter Range west of Mercury, the government town at the Nevada Test Site, 65 miles northwest of Las Vegas.

The herd's 113 animals might have been stressed by the 2002 drought, making them more susceptible to disease, said Geoff Schneider, spokesman for the department's Las Vegas office.

Officials have seen only "very few lambs in that population over the past couple years," he said in an an e-mail message Wednesday.

He noted that there was a major disease-related die-off of desert bighorns in 1980 in the Mormon Mountains, northeast of the Las Vegas Valley.

"After that, the population rose and peaked in 1993. Then there was a die-off in 1995-96, although it wasn't as significant as the 1980 event."

During a project last year to relocate 25 desert bighorns from the Lake Mead area to the Delamar Range in Lincoln County, researchers checked the captured animals for evidence of pasteurella, a bacteria that produces a sometimes-fatal infectious respiratory disease.

In Northern Nevada, experts are particularly concerned because the Santa Rosa herd of California bighorns 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 had approached 300.

Concern arose just before Christmas when state officials started hearing stories of hunters finding sick and dead bighorns.

Alton Ward, a microbiologist and retired professor with the University of Idaho, prepared a report on the die-off that recently was submitted to the Nevada wildlife agency.

Whatever the source of infection, what does appear clear is that the Santa Rosa bighorns were weakened substantially 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 diminished nutritional intake further and made the bighorns more susceptible to infection resulting in the pneumonia that killed them.

Review-Journal writer Keith Rogers contributed to this report.

The above can be seen at: http://www.reviewjournal.com/lvrj_home/2004/Jun-10-Thu-2004/news/24069877.html
Other appearances of this information can be found at: http://www.nctimes.com/articles/2004/06/10/special_reports/science_technology/21_57_136_9_04.txt and http://www.azcentral.com/news/articles/0609bighornsheep-ON.html