Are predatory kills by mountain lions the reason for the decline in bighorn sheep numbers in the Tonto National Forest? The Arizona Game and Fish Commission's approval of a program to open a planned lion hunt in the area indicates officials consider the animals responsible for shrinking herd numbers.
But there are some, including Arizona Game and Fish big-game biologist Ray Lee and field officers, who say that the reasons could lie elsewhere. Acquisition of domestic livestock diseases by the bighorn and the quality of the habitat that sustain the sheep are among the causes.
Lee says a study to uncover the reasons began about four months ago and will continue for three years.
The study will focus on depredation by lions, the dwindling capacity of the land to support the animals and domestic livestock diseases.
Game officials are expected to focus much of their attention on the bighorns 'interaction with domestic sheep being herded through the Tonto National Forest each year. The contact occurs when sheep are taken to summer grazing fields near Springerville from their winter feeding grounds near Mesa.
Scientific studies of the bighorn indicate the animals could be contracting diseases from the domestic sheep, Lee says.
Because bighorns are wild and do not have the immune system that domestics possess, they cannot fend off the diseases.
Nancy Zierenberg, executive director of the Wildlife Damage Review in Tucson said she also believes infections acquired from domestic sheep could lie at the heart of the bighorn decline.
"I've had hunters come to me with their concerns about the diseases and parasites the species (bighorns) have picked up. They've seen them first hand," she said.
Zierenberg also said she was opposed to the commission's OK of the mountain lion hunt. "First, we don't know (the lions) are the reason (for declining bighorn herds), and second, (the lions) serve a purpose -- they help keep their prey in good health."
In addition to diseases acquired from domestics, Zierenberg is convinced bighorn populations have been adversely affected by declining habitat.
"We've pushed them into smaller and smaller areas. We must protect their habitat and solve the domestic disease problem, not kill (the mountain lions)," she said.
Zierenberg compared the mountain lion hunt to one the commission approved of last year when marksmen killed 67 coyotes from airplanes near Flagstaff. The coyotes were allegedly threatening the declining pronghorn antelope population.
Neither the lion or coyote hunts, Zierenberg says, are answers to the problems that threaten wildlife.