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October 23, 2014

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Bighorns find summer home in Boulder City

When Pam and Greg Heilman were considering buying a Boulder City home in the River Mountain foothills overlooking Lake Mead two years ago, they saw members of a herd of desert bighorn sheep perched majestically on a nearby ledge.

"That pretty much closed the deal for us," Pam said. "Who expected to see bighorn sheep come so close to humans? It was amazing -- really neat.

"I still enjoy watching the sheep, but now, maybe there are too many of them" in the residential area.

The state Division of Wildlife, which oversees the herd that each summer treks to Boulder City's Hemenway Park to graze on the thick grass, agrees, and officials are concerned about the danger to Nevada's state mammal.

The animals will face even more danger as man further encroaches on their habitat by building new homes and carving out bike and hiking trails.

"In the last couple of years there have been 50 or 60 bighorns a day (at Hemenway Park), which is excessive from a management standpoint," said Patrick Cummings, a biologist for the state wildlife department who oversees several area sheep herds.

"It (mingling with man) is not a good thing because wild animals need to remain wild. Bighorn sheep are not desirable in urban areas because they are being hit and killed by vehicles and harassed by domestic dogs."

In the wake of the unknown causes of the recent deaths of 21 bighorn sheep in the McCullough Range south of Las Vegas, state officials more than ever want to reduce the danger level to the River Mountain herd.

This fall, several ewes and rams from the River Mountain herd that numbers about 200 adults will be captured and sent to the Virgin Mountains east of Mesquite.

That should reduce the numbers of sheep that come down to Hemenway Park, Cummings said.

Since at least the late 1980s, the bighorn sheep have made daily treks up and down the River Mountains during the hot and dry summer months because natural mountain vegetation has withered.

Cummings said at least three to five adult rams and ewes are killed by passing motorists each year even though yellow Nevada Department of Transportation signs are posted along U.S. 93 warning of potential sheep crossing.

But Cummings questions the accuracy of those statistics because they cannot possibly account for the unexplained loss of sheep who are hit by cars and limp off the roads to die and rot away in the triple digit desert heat, leaving no trace of such run-ins with cars.

"There are only about 5,000 to 5,500 bighorn sheep statewide," Cummings said. "The herds are intensely managed."

That management includes limited hunting -- and the River Mountain sheep are off limits to hunters, he said.

Kathy Longshore, a research wildlife ecologist with the U.S. Geological Survey, who has studied the bighorn sheep on and off since 1987, is in the midst of a lengthy study of nine River Mountain bighorns who are equipped with electronic tracking collars.

There originally were 10 sheep in the study, but one has been killed, which speaks volumes for the need of the study, she said.

"Some Boulder City residents have put out water sources for the sheep, and that is not necessarily good," she said. "The people are trying to be helpful to the sheep, but their homemade watering holes are encouraging the sheep to come down to an area where they face all sorts of dangers."

Longshore's study also is looking at whether the grass at Hemenway Park is as digestible and as nutritious as the shrubs and winter annuals that grows wild on the mountain.

"Just because the Hemenway Park grass is a lot greener than their natural shrubbery -- and just because the sheep might like it -- does not mean that grass is nutritious or good for them," she said.

The results of Longshore's study, which includes collecting everything from behavioral data to droppings, are expected to be released in a report in the fall of 2006.

Heilman said the sheep "are amazing to watch."

"The residents here really like them,' Heilman said. "We understand that some of them will have to be moved to thin out this heard. I wouldn't like it if they decided to move all of them away."

Even if left alone in the wild, bighorns face daily danger from predators such as coyotes, bobcats and the occasional cougar that wanders through the River Mountain. Sometimes, as in the case of the dead sheep in the McCullough Range, the dangers may not be so apparent.

Cummings, who was in that area early this week to be part of the investigation of the dead sheep that were found by all-terrain vehicle riders, said a number of possible causes of death are being considered, including lightning strikes, water contamination and the recent record heat.

No bullets were found in the area, Cummings said, noting that tissue was taken from the dead animals and sent to a laboratory at the University of California, Davis, for tests, the results of which could take several weeks to return.

Longshore and Cummings agree that the best chance the River Mountain bighorn sheep have of thriving in a world where man is forever stretching his wings is public awareness.

"Education can be a real plus," Longshore said. "After all, There is no true solution. Man will keep building and the sheep likely will keep coming down from the mountains to graze."

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