BigHornRam
Well-known member
Canyon bighorns lose most of their lambs
Tuesday, January 08, 2008
BC-WST--Bighorn Die-off,0376 ENTERPRISE, Ore. (AP) -- Disease killed about 80 percent of the lambs born last spring to the bighorn sheep in Hells Canyon, and biologists call it the worst die-off since the breed was reintroduced there in the early 1970s.
Researchers believe the deaths were triggered by one bacterium that inhibits the bighorns' ability to fight off another bacterium that leads to bronchopneumonia. Lambs appear to be most vulnerable because of undeveloped immune systems, said Vic Coggins, an Oregon Department of Fish and Wildlife biologist.
"This was the worst year I've ever seen for lambs," said Neil Thagart, spokesman for the Foundation for North American Wild Sheep in Cody, Wyo.
The canyon of the Snake River is home to about 900 RockyMountain bighorns. Thagart has visited it after lambing season for about 10 years. The river separates Idaho from Oregon and Washington.
The die-off appears to have spared a big share of the wild adult rams and ewes, Coggins said.
In an average year, 35 percent to 40 percent of lambs survive and up to 60 percent occasionally make it through their first year, he said.
But big die-offs are not uncommon. In Hells Canyon, 71 percent of bighorn lambs died in 2006, Coggins said. In 2004 and 2005, 74 percent died.
An estimated 2 million bighorns once lived in the American West, compared with about 15,000 in 1975 and about 70,000 today.
The bighorns of Hells Canyon represent a long-term effort begun in 1972 to replace herds that had disappeared by 1940.
California bighorns, a related breed, were gone from eastern and central Oregon from 1910 until 1954, and they now number about 3,500, Coggins said.
Biologists and environmentalists have insisted for years that a relationship exists between bighorn deaths and disease-resistant domestic sheep and goats, which serve as infection hosts.
The U.S. Forest Service ordered more than 7,000 domestic sheep off the Oregon side of Hells Canyon in 1996, ending a sheep-grazing tradition dating to the 1870s.
But domestic sheep still are found on federal allotments in Idaho and on private property, Thagart said, and Coggins said he has seen bighorn rams swimming the river.
Tuesday, January 08, 2008
BC-WST--Bighorn Die-off,0376 ENTERPRISE, Ore. (AP) -- Disease killed about 80 percent of the lambs born last spring to the bighorn sheep in Hells Canyon, and biologists call it the worst die-off since the breed was reintroduced there in the early 1970s.
Researchers believe the deaths were triggered by one bacterium that inhibits the bighorns' ability to fight off another bacterium that leads to bronchopneumonia. Lambs appear to be most vulnerable because of undeveloped immune systems, said Vic Coggins, an Oregon Department of Fish and Wildlife biologist.
"This was the worst year I've ever seen for lambs," said Neil Thagart, spokesman for the Foundation for North American Wild Sheep in Cody, Wyo.
The canyon of the Snake River is home to about 900 RockyMountain bighorns. Thagart has visited it after lambing season for about 10 years. The river separates Idaho from Oregon and Washington.
The die-off appears to have spared a big share of the wild adult rams and ewes, Coggins said.
In an average year, 35 percent to 40 percent of lambs survive and up to 60 percent occasionally make it through their first year, he said.
But big die-offs are not uncommon. In Hells Canyon, 71 percent of bighorn lambs died in 2006, Coggins said. In 2004 and 2005, 74 percent died.
An estimated 2 million bighorns once lived in the American West, compared with about 15,000 in 1975 and about 70,000 today.
The bighorns of Hells Canyon represent a long-term effort begun in 1972 to replace herds that had disappeared by 1940.
California bighorns, a related breed, were gone from eastern and central Oregon from 1910 until 1954, and they now number about 3,500, Coggins said.
Biologists and environmentalists have insisted for years that a relationship exists between bighorn deaths and disease-resistant domestic sheep and goats, which serve as infection hosts.
The U.S. Forest Service ordered more than 7,000 domestic sheep off the Oregon side of Hells Canyon in 1996, ending a sheep-grazing tradition dating to the 1870s.
But domestic sheep still are found on federal allotments in Idaho and on private property, Thagart said, and Coggins said he has seen bighorn rams swimming the river.
