Red Lodge Clearinghouse

On May 30, the U.S. Fish and Wildlife Service announced that federal protection for the cactus ferruginous pygmy owl may be warranted, launching a one-year status review.

The bird inhabits parts of southern Arizona, including patches of land considered prime real estate. Given the intense development interest in that area, developers successfully sued in 2001 to have the owl removed from the list.

FWS' decision to review the birds' status follows a May 20 notice from three environmental groups -- the Center for Biological Diversity, Defenders of Wildlife and Public Employees for Environmental Responsibility -- indicating they would file suit if the agency did not respond to their petition urging FWS to restore protections to the diminutive raptor.

"We find that the petitioners have provided reliable and substantial scientific information that a taxonomic revision may be warranted," the agency wrote in its finding on the petition, which was published in the Federal Register on June 2.

If FWS decides that the bird's listing is, indeed, warranted, it will be the owl's second appearance on the ESA roster. The agency named the cactus ferruginous pygmy owl population in Arizona an endangered "distinct population segment" in 1997. Developers sued a few years later, and in 2003, the 9th U.S. Circuit Court of Appeals ruled that in listing the bird, FWS had failed to show that it met all three criteria for its classification as a distinct population segment. Specifically, FWS did not demonstrate that the bird was significant to the survival of the species as a whole, the court said. The agency subsequently delisted the Arizona bird in 2006. The delisting decision remains on appeal in the 9th Circuit.

Meanwhile, environmental groups also petitioned FWS to restore ESA protections to the owl, arguing that the agency had ignored scientific information that suggests the pygmy owl in Arizona, which is part of the same subspecies found in Sonora and Sinaloa states in northern and central Mexico, still needs federal protection.

"The pygmy owl should never have been removed from the endangered species list," said Noah Greenwald, a conservation biologist with the Center for Biological Diversity who helped write the petition. "The pygmy owl is near extinction in Arizona and sharply declining in northern Sonora. It desperately needs the protection of the Endangered Species Act to survive."

The Arizona population constitutes the last remaining U.S. population of the Western subspecies of cactus ferruginous pygmy owls, according to the groups' petition.

New taxonomic data

While the birds in Arizona may share genes with their cousins south of the border, the new taxonomic data indicates that cactus ferruginous pygmy owls in Arizona and northern Mexico are distinct from other owls in Texas and eastern Mexico -- a distinction that effectively cuts the Western population's range in half, said Jeff Humphrey, a spokesman for FWS in Arizona.

"There's information that suggests that the cactus ferruginous pygmy owl [in Arizona and northern Mexico] may belong to a smaller taxon than it did historically," he said. "So by that virtue, it may be more significant."

Scientifically speaking, under the original taxonomy, the pygmy owls in southern Texas were classified as the same subspecies as the owls in Arizona. The new data will likely lead to reclassification of the Arizona and northern Mexico owls as a different subspecies from the Texas owls, according to the Federal Register notice.

Humphrey said the new studies were not peer-reviewed at the time FWS issued its finding in 2006. Those new analyses, which have since been published in peer-reviewed journals, will carry more weight during the status review, he said, adding that the agency will also consider other, nonpublished data that can contribute to FWS's understanding of the bird's status.

Ecological challenges

The reddish-brown, white-bellied owl nests primarily in the cavities of the saguaro cactus. Urban development around the fringes of the city of Tucson has reduced the numbers of the cacti that the owls depend upon, and global warming has also played a role in diminishing habitat critical to the raptors, according to a recent report by the Defenders of Wildlife.

As a result, the population of cactus ferruginous pygmy owls in Arizona has decreased from 41 birds in 1999 to 30 birds in recent years, according to the petition. The bird appears to be ecologically challenged south of the border as well: Recent research conducted by the University of Arizona showed that the pygmy owl population in Sonora, Mexico -- immediately south of the Arizona border -- has suffered a 26 percent decline since 2000. Humphrey said part of that decline is due to the expansion of African buffelgrass, an invasive species that outcompetes the saguaro cacti whose cavities provide shelter for the bird.

"The reality of the owl's status never actually changed," said Matt Clark of Defenders of Wildlife's Tucson, Ariz., office. "Just the political, legal reality."

FWS will consider the numerous threats to the owl, but it will also take into account conservation measures aimed at reversing the bird's decline, Clark added. Those include the Sonoran Desert Conservation Plan, Pima County's Multiple Species Conservation Plan and a new effort being developed by the city of Tucson, Humphrey said.

Clark warned that those plans are not enough to recover the pygmy owl. "I don't think they could justify not listing the owl because of the mere existence of these plans," he said. "The entities that have developed these conservation plans generally do not have the funding required to recover the species, and it needs federal protection."

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