Troubling Drop in AZ and NM Gray Wolf Population
February 10, 2010
PHOENIX - Mexican gray wolf numbers are dropping in Arizona and New Mexico, down 20 percent in the past year. The 42 remaining endangered wolves are part of a reintroduction program that began in 1998.
Dr. Rich Fredrickson, a University of Montana wildlife biologist, says the falling numbers threaten the genetic diversity needed for the wolf packs to become self-sustaining, because many pups seeking to mate are closely related.
"So when those pups grow up and they look for mates, it's going to be hard for them to find a mate that's not closely related to themselves. And the likely result of this is that the fitness of the Blue Range population is going to decline with time."
Fredrickson says the U.S. Fish and Wildlife Service, which manages the reintroduction program, needs to develop a science-based recovery plan with explicit attention to genetic management and goals. For his part, Fish and Wildlife Service Regional Director Benjamin Tuggle pledges to find the reasons for the wolves' decline, and reverse it.
Fredrickson says one strategy, known as genetic rescue, would introduce genetically unrelated wolves into the Arizona-New Mexico border region.
"These immigrants bring increased fitness of the overall population, and that fitness increase can last for several generations after the immigrants themselves are dead and gone."
He sees the gray wolf recovery effort as part of the commitment society made when President Nixon signed the Endangered Species Act in 1973.
"The Endangered Species Act requires the federal government to do their best, to recover endangered species to levels where they can survive without strong intervention."
Some ranchers have opposed reintroduction because of instances in which wolves have killed livestock or pets. Conservation groups have responded with fencing projects, mounted patrols and reimbursement for losses.