From: http://www.azstarnet.com/allheadlines/156726

Refuge bighorn numbers shrinking

The Associated Press

Tucson, Arizona | Published: 11.19.2006

YUMA — The population of desert bighorn sheep on the Kofa National Wildlife Refuge, in southwestern Arizona near Yuma, has plummeted, a recently completed survey shows.

The survey estimated the sheep population at 390, down by 230 animals from the last survey estimate of 620 in 2003 and fewer than half the 812 sheep estimated in 2000.

The numbers mean that the decline in bighorn sheep on the refuge seen in 2003 continues and that those numbers may have reached or are close to the lowest levels recorded.

U.S. Fish and Wildlife Service officials pointed to drought and possibly predatory mountain lions as the likeliest contributors to the decline.

But environmental groups say there's a much broader reason for the decline, and it's not just predators or lack of water.

"What they do is they look for what I consider is the easy answer, versus taking on the bigger issues," said Sandy Bahr, conservation outreach director for the Sierra Club's Grand Canyon chapter. "For bighorn sheep, certainly, habitat fragmentation is the biggest issue."

The government report noted that the falloff in 2003 came after a severe drought year in 2002.

Fish and Wildlife, which is in charge of the 665,000-acre refuge, has conducted the surveys jointly with the Arizona Game and Fish Department every three years since 1992.

The data reflect an overall downward trend in numbers of the bighorn sheep in southwestern Arizona that began with the drought year of 1996, Fish and Wildlife said.

Among possible factors for the decline being studied by Fish and Wildlife is predation by mountain lions, disease, availability of permanent water and public recreational disturbance in areas where female sheep give birth.

The Kofa population of bighorn sheep has been a significant source for repopulating other herds in Arizona and from Colorado and New Mexico to Texas, including 30 sheep captured and transported in 2005 to the San Andres National Wildlife Refuge in New Mexico.