Refuge plan for lions, sheep complete
Under the U.S. Fish and Wildlife Service's new mountain lion management plan, when the bighorn sheep population on the Kofa National Wildlife Refuge is above 800, if a mountain lion kills two or more bighorn sheep within a six-month period, it won't have to be lethally removed from the refuge.
"Our goal is not to remove all the mountain lions from the refuge. That is not what we are trying to do," said Mitch Ellis, refuge manager of the Southwest Arizona National Wildlife Refuge Complex. "We just want to be able to control mountain lion predation to meet our sheep population objectives."
The USFWS announced Friday that it had completed its plan for managing mountain lions.
Ellis said the announcement of the plan comes after over two years of analysis and planning that included participation by the general public and other agencies and organizations.
Specifically, Ellis said, the management plan lays out a scientifically supported process for lethal removal and/or translocation of individually identified mountain lions that kill two or more bighorn sheep within a six-month period.
Under this program, mountain lion removals would only occur to meet desert bighorn sheep population objectives.
"It is very important that we maintain this herd to a sufficient size to be able to support the restocking of other herds elsewhere," Ellis said.
When the refuge sheep population estimate is below 600, active lion control would occur. When the sheep population estimate is between 600-800, limited lion removals may occur based on criteria outlined in the plan. When the sheep population is at or above 800, no lion removals would occur.
"We wanted some flexibility," Ellis said. "So if all the conditions were good, there would be no need for a removal."
Ellis explained that when the bighorn sheep population is between 600 and 800, a number of criteria would be looked at in determining whether to lethally remove a mountain lion, such as the population trends, how favorable the habitat conditions have been and whether a herd anywhere is in need of being restocked.
Kofa National Wildlife Refuge was originally established in large part for the protection of the desert bighorn sheep.
Unfortunately, Ellis said, the sheep population has declined significantly from a long-term average of 760 bighorn sheep to near 400 over the past four years.
"Between 2001 and 2006, the bighorn sheep population declined by about 50 percent," Ellis said.
This nearly 50 percent population decline prompted the development of an investigative report co-authored by the Arizona Game and Fish Department and the USFWS.
The resulting report outlined several management actions to address the declining population. Limiting mountain lion predation was a key management action identified for improving the status of the sheep on the refuge.
“We’ve taken a comprehensive look at the full array of factors impacting bighorn sheep on the refuge and ways to overcome those impacts," Ellis said. “We feel confident that judicious removal of offending lions is a tool that will help us in conservation of desert bighorn.”
A copy of the final environmental assessment, a list of questions and answers and a library of all other documents pertaining to the decision are available by visiting fws.gov/southwest/refuges/arizona/kofa.
Ellis went on to say that although the bighorn sheep population is still down from historic highs, it has remained at about 400 the past four years.
"We are happy it hasn't gone down, but we expected a slight population increase. We have had favorable weather conditions the past few years, which has led to favorable habitat conditions."
Ellis added that the mountain lion population has been stable over the years and staff is also trying to determine how many are currently on the refuge. He said there may be as many as five or six.
"Mountain lions are being seen in other parts of the state where they haven't been common in years past. They are starting to reoccupy marginal habitats."