More than 17 years after developers filed a lawsuit to remove federal protection from the cactus iron pygmy owl of the Tucson area, the U.S. Fish and Wildlife Service is back in action to protect the tiny desert owl.

Federal officials added the pygmy owl to the endangered species list on Wednesday, ruling that the small raptor faces habitat destruction and fragmentation by development, climate change and invasive species such as fire-causing baffled grass.

This relisting is a change from the previous list, when the owl was listed as endangered from 1997 to 2006, preventing construction of several housing developments in the Tucson area.

But Adelita Grijalva, chairman of the Pima County Supervisory Board, said the redesignation would not create new “land use conflicts” because the county has spent the intervening years building its own conservation efforts.

Federal officials said the cactus pygmy owl, a small owl that measures 7 inches long and weighs about 2.6 ounces and weighs just over a tennis ball, should be classified as endangered under the Endangered Species Act of 1973. The decision comes after a 12-month survey of pygmy owl habitat that was initiated after the Tucson-based Center for Biodiversity and Wildlife Conservation Group filed multiple petitions and lawsuits seeking protection for the pygmy owls.

Research shows that there are only a few hundred small Aedes remaining in the Tucson area.

“The ferocious little cactus iron pygmy owl needs our care and protection, and after a long battle, we finally have it,” said Noah Greenwald, endangered species director for the Tucson-based Center for Biodiversity. “If we lose this owl, we will lose the Sonoran Desert and much more. To stop this extinction crisis, we must protect more of the natural world, invest in remediation, and phase out fossil fuels.”

In December 2021, the FWS said it would reconsider the owl as a threatened species, writing, “After reviewing the best available scientific and commercial information, we have determined that listing the subspecies is justified.” The agency said the owl’s “endangered” status was necessary because, while it did not face immediate threats to extinction, it faced stressors severe enough to put them at risk of extinction in the future.

The agency said Wednesday that owls need stronger protection and that the changes “are based on an additional decade of threats, land-use change and climate change that have impacted the landscape within the pygmy owl’s range.”

“Enough time has passed since the initial projections of climate change impacts to confirm evidence of projected impacts on vegetation communities throughout the pygmy owl’s range,” officials said. “Generally, these impacts were in line with or worse than projections. New climate models and projections, and generally updated information were available for our analysis.”

The agency said the development was related to the disappearance of owls in Pinal County and northwest Tucson, where they were spotted in the early 2000s.

“Although there is no direct correlation between the area of ​​pygmy owl habitat loss and human population growth, it is reasonable that the amount of native habitat loss or fragmentation increases as the human population increases,” officials said.

The FWS also noted that the owl “has become reliably undetectable at the Organ Pipe Cactus National Monument for the first time since records were kept,” and noted that this was likely the result of the Trump administration’s attempt to build a 30-foot-tall steel “bollard” wall across the reserve.

FWS said it “concluded that the designation of critical habitats is prudent and determinable at this time.”

The owls will receive new protection, but Pima officials said they have changed the way the county manages land around Tucson.

“The endangered listing of the cactus pygmy owl in the 1990s created uncertainty about where and how our region will grow,” Grijalva said in a press release. “Pima County has taken the lead in creating a Conservation Land Management System to bring greater development certainty to our region and balance the conservation of fragile deserts with the need for community growth and prosperity.”

In 2004, county voters “voted overwhelming support for the plan by approving more than $100 million in bond financing for sensitive land acquisitions,” and Pima County now owns or controls more than 250,000 acres of sensitive land.

“With the county’s Landmark Sonoran Desert Conservation Plan, its accompanying Multispecies Conservation Plan, and the U.S. Department of the Interior’s Section 10 permit, the re-registration of the pygmy owl and its designated critical habitat will not provoke the kind of land-use conflicts that it did in the 1990s and early 2000s,” Grijalva said. “The pygmy owl only adds to the list of other endangered species whose habitat is protected and preserved by the people of Pima County,” the Environmental Plan said.

Little owls cause big fights

In 1992, the Center for Biodiversity successfully petitioned federal authorities to protect the pygmy owl as an endangered species. However, the owl was delisted after a long-running battle over its habits, including its role in maintaining the 6,500-family housing block in Marana that led to the establishment of the 2,400-acre Tortorita Sanctuary.

The FWS removed the owl from its endangered species list, arguing that it was unclear whether the decline in the bird’s population in Arizona would have a significant negative impact on the survival of the subspecies as a whole.

In 2014, environmental groups in Tucson sued federal officials over their decision to delist the pygmy owl, and a federal court agreed, ruling that federal officials misinterpreted the Endangered Species Act. In 2019, a federal court gave the FWS a deadline to reconsider the status of pygmy owls, ruling that the agency must publish by August 5, 2021, the results of a 12-month investigation into whether listing pygmy owls is warranted.

FWS began investigating the owl’s situation months after the court-imposed deadline.

While the lawsuit is pending in court, new data and research methods show that while there are positive signs across the owl’s range, future threats over the next 30 years are likely to result in habitat loss and fragmentation.

The FWS applauds Pima County’s efforts to protect pygmy owls, and a survey completed under the county’s Species Conservation Plan shows that many birds live in the Alter Valley, about 29 miles west of Tucson, between the Tucson and Babokbari Mountains.

Dr. Aaron D. Fresh, a researcher at the University of Arizona Desert Research Institute in Tumamook Hills, surveyed pygmy owls on protected land in Pima County and produced a June 2021 report as part of the county’s multispecies conservation plan.

In 2020, Fresh spent several weeks studying pygmy owls, first during the breeding season in April and again in October when young owls were dispersing and choosing their range.

Fresh said in his report that he had found “significant owl populations” in Altar Valley and that his research “confirmed the value” of the Pima reserve. He also recommended the woodpecker, noting management efforts to promote “saguaro breeding, adoption and survival,” and that owls use cavities carved into the saguaro by woodpeckers as nests.

However, in Texas and Chihuahua, Mexico, pygmy owls are threatened by agricultural development and population growth. Farther south in Mexico, pygmy owls are more numerous, but are expected to continue to decline due to habitat loss due to urbanization and agriculture.

The agency said the owl’s “endangered” status is less restrictive than the endangered classification, but registration would require education and outreach efforts under the Migratory Bird Treaty Act, and may also require habitat restoration or “strengthening activities” to improve the pygmy owl’s habitat.

A 2020 study by Arizona Game and Fish estimated the bird population in Arizona to be in the low hundreds.