PHOENIX — Two environmental groups filed a lawsuit Tuesday aimed at forcing the federal government to protect Arizona’s diminishing cactus ferruginous pygmy owl population under the Endangered Species Act.
The Sonoran Desert of southern and eastern Arizona is home to about 50 of the owls. While Arizona’s population is one of two small populations in the United States, there are significant populations of pygmy owls in Mexican states of Sonora and Sinaloa.
The lawsuit filed by Defenders of Wildlife and the Tucson-based Center for Biological Diversity calls for the U.S. Fish and Wildlife Service to list the owl as endangered. It also challenges a recent policy change by the agency that the groups say could make it more difficult to get the owls protected.
“We’ve seen repeated attempts to narrow the range of the Endangered Species Act and add hurdles to getting species listed,” said Jason Rylander, staff attorney for Defenders of Wildlife.
The Endangered Species Act states that a species can be protected if it is threatened or endangered in a “significant portion of its range.” In July, the Fish and Wildlife Service announced that a portion of range is significant only if the species would become in danger of extinction unless that range is protected.
Because of the populations in Mexico, the agency can avoid listing the owls under the Endangered Species Act, as they don’t need the Arizona population for the subspecies as a whole to survive, the groups argue.
“The current director (of the Fish and Wildlife Service) seems to believe that his sole directive is to protect extinction in the world,” Rylander said.
Jeff Humphrey, a spokesman for the Fish and Wildlife Service in Arizona, said the agency doesn’t comment on pending litigation. However, he provided links to the agency’s explanation of the change.
“The purpose of this final policy is to provide an interpretation and application of ‘significant portion of its range’ that reflects a permissible reading of the law and minimizes undesirable policy outcomes, while fulfilling the conservation purposes of the Act,” reads the agency’s final policy statement.
Pygmy owls were once more common in Arizona, but urban sprawl from Phoenix and Tucson in the 1970s and ’80s has eliminated much of their habitat, according to Noah Greenwald, endangered species director for the Center for Biological Diversity.
A change to the Endangered Species Act in 1997 defined the cactus ferruginous pygmy owl as a “distinct population segment” that could be protected under the Act.
Greenwald said that the designation lasted until 2006, when the Fish and Wildlife Service faced a lawsuit that questioned whether the Arizona population contributed to the subspecies as a whole. After the court concluded that it didn’t, and that the population wasn’t a distinct subspecies, the agency stripped the Arizona owls of their status.
“There are some genetic differences with the birds in Arizona, but it’s difficult to prove,” Greenwald said.
The most recent effort to return the owls to the Endangered Species List came in 2011, when environmental groups argued that the Sonoran Desert population’s increased resistance to heat made it a significant population from a genetic perspective. While the case was decided out of court, Rylander said that there was evidence that biologists from the Fish and Wildlife Service were beginning to consider the Sonoran Desert population as a significant part of the animals’ range, before the June reversal.
“What we have here is a policy determination, divorced from the best available science, and because of that they have denied protection to a very interesting and important animal,” Rylander said.