Bad news for bighorns
Small bighorn sheep herd near Gunnison suffers major losses



By DAVE BUCHANAN
The Daily Sentinel

Sunday, January 06, 2008

A small herd of Rocky Mountain bighorn sheep that live east of Gunnison suffered a major population loss recently when at least eight of the animals were found dead during the last week of December.

The first report of dead sheep was made by a rancher who called the Gunnison office of the Colorado Division of Wildlife to say he found three dead bighorns near one of his fields.

When DOW officers showed up to investigate, another sheep was so sick it had to be euthanized. A subsequent search by DOW officers turned up four more dead sheep.

Bighorn sheep are notoriously sensitive to environmental and physical impacts, ranging from too much pressure from curious wildlife watchers to illnesses contacted from domestic livestock including sheep, goats, horses, cattle and llamas.

Several herds of bighorn sheep, including those near Georgetown and in southwest Colorado, have been wiped out or nearly so after coming in contact with domestic sheep herds. The main cause of death was reported to be pneumonia, a result of infections of the Pasteurella bacteria from domestic sheep.

Chris McDaniel, a researcher with the University of Idaho, wrote that “Pasteurella has been linked to severe die-offs of wild bighorn sheep in all of the western United States ... through contact with domestic sheep and yet (Pasteurella) has no negative effect on the domestic sheep†which have become immune carriers of the bacteria.

In his paper “From Me to Ewe: Interactions between Wild Sheep and Goats and Domestic Livestock,†McDaniel noted that bighorn herds in the San Juan Mountains of Utah “experienced a 98 percent herd reduction over an 18-year period due to Pasteurella related die-offs.â€

The DOW isn’t yet pinpointing any certain causes of the Gunnison die-off, according to J Wenum, area wildlife manager, although early findings from field postmortems suggested that pneumonia was the likely cause of at least some of the bighorn deaths.

While any unexplained wildlife losses are of concern to biologists, these animals were part of the Fossil Ridge herd which numbers only around 50 sheep. Without much to go on, about the only thing biologists can do for now is monitor the rest of the herd, Wenum said.

It’s extremely difficult to administer antibiotics to wild animals and past attempts to treat pneumonia outbreaks in bighorns around the state have not been particularly successful, he said.

“It’s not like cattle, where you can run them into a pen and make sure they get the proper dose,†Wenum said.

Wenum also reminded winter wildlife watchers to keep their distance when viewing wild animals, whether it’s bighorn sheep, mule deer, elk or moose. Winter is a time of stress and slow starvation for wild animals and even the smallest disturbance might push an animal to the point between survival and death.

Big-game animals can lose 30 percent of their body weight during the winter, said a DOW biologist. People getting too close, whether simply curious or seeking shed antlers, could force animals to move and burn extra calories that cannot be replaced.

“If people want to watch wildlife during the winter, we ask that they use binoculars or a spotting scope and observe from a distance,†Wenum said. “If animals move when they see you, you are too close.â€

On the national front, Ducks Unlimited says enough Conservation Reserve Program grassland acres were lost last year in North Dakota alone to equal plowing a three-mile swath of wildlife habitat across the state.

Figures released by the U.S. Department of Agriculture’s Farm Service Agency show nearly 420,000 acres of North Dakota CRP were converted to cropland in 2007, an amount equal to more than 12 percent of all CRP acres in the state.

“If this trend holds for CRP contracts across the country, we won’t have many acres of CRP left in a few years and wildlife populations will suffer serious declines,†said Scott McLeod, Farm Bill specialist with DU’s Great Plains Regional Office.

According to the U.S. Fish and Wildlife Service, CRP acreage is vital to waterfowl nesting, particularly in the Prairie Pothole region where such lands produce more than 2 million ducks each year. Losing CRP lands means few ducks in all 48 states and loss of hunting opportunity.

Biologists from DU say rising commodity prices, especially the focus on corn as a source of ethanol, have created a push to return CRP lands that provide valuable wildlife habitat back to crop production once the CRP leases expire.

One of the negatives, in addition to loss of unfarmed lands for wildlife, is that most CRP lands are marginal farmlands and often highly erodible once plowed.

At the crux of the concern is the country’s newest energy policy that pulls billions of federal dollars from natural resource programs, a DU spokesman said.

“Conservation is in for a long swim against a strong current when trying to fight the tide of land rolling out of CRP,†said Jim Ringelman, DU’s director of conservation programs in the Prairie Pothole Region.

“The loss of CRP is certainly a severe blow to waterfowl and other grassland-dependent wildlife, but native prairie cannot be replaced,†he said. “Native prairie and wetland complexes are critical habitats for nesting waterfowl and ranchers alike.â€

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This exact same thing happened in a small herd we had here in South Dakota.

The population went from approx 200 bighorns down to about 40. Appropiately the season was closed.

The second bad part of the equation is, with the high mountain lion depredation, they don't really expect the herd to recover.