Southwest Environment

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Department of Soil, Water and Environmental Science
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Delisting of Bald Eagle challenged for Arizona population

By Matt Lewis

watching nest through spotting scope


Photo by Matt Lewis
Nest watcher Leah Vader peers through the spotting scope at a fledgling eagle about half a mile while her colleague Jennifer Ottinger takes notes.
“The baby is out there,” Leah Vader said, pointing in the distance toward a tree that looked dime-sized to the naked eye. She gestured toward the spotting scope, inviting a guest to peer through it at the brown-feathered fledgling. Did she know its age?

“Of course I know how old it is. I can tell you to the exact day,” Vader responded with a smile. As an official nest watcher, she and her co-worker Jennifer Ottinger had been stationed at this nest site since February taking copious notes about every move made by the bird and its parents.

The Arizona Bald Eagle Nestwatch Program continues despite the 2007 delisting of the American Bald Eagle from the protection of the national Endangered Species Act. U.S. Fish & Wildlife delisted the iconic raptor, stating the national population showed evidence of being sufficiently recovered. The agency noted on an August 30, 2006, petition that 7,066 breeding pairs of bald eagles lived in the conterminous 48 states, up from an estimated 417 in 1963.

However, many groups in Arizona – such as the Arizona Game and Fish Department, the Center for Biological Diversity, and some biologists with the U.S. Fish and Wildlife Service – argue that the state contains a distinct population of bald eagles. There are about 50 known nesting pairs in Arizona, with 95 percent of the population residing below the Mogollon Rim, said Kenneth Jacobson, the Bald and Golden Eagle Management Coordinator for Game and Fish.

Jacobson and others maintain the Arizona population should qualify for a "distinct population segment” because they are the only eagles in the world that nest, breed, and live in the desert. This distinction, if met, would afford the local population coverage under the ESA.  

The Center for Biological Diversity is leading the lawsuit against the FWS to get protection for the desert nesting bald eagle as a distinct population segment under the Endangered Species Act. The Arizona population, which some call the Sonoran Bald Eagle, is the only population of eagles in North America that lay their eggs in low such a hot and dry environment, according to Robin Silver, a co-founder of the center who is spear-heading this lawsuit. 

One distinction is that their eggs are thicker and less porous than a typical eagle egg, which Silver attributes to an adaptation to the dry desert climate. The population also meets the standard for being isolated, he said, because of  only two eagles outside of the population in the past 40 years have been recorded entering or leaving the breeding grounds.

Twenty tribes in Arizona joined the lawsuit as “friends of the court.” Members are providing information to help support the case, Silver said, noting that the tribes have shared their long documented record of past eagle nest locations that are now non-existent because of human encroachment. 

“The Bald Eagles in Arizona have a special cultural and religious significance to all tribes in Arizona,” states a March 9, 2007, resolution by the Intertribal Council of Arizona, which represents the 20 tribes.  The resolution specified that they want proper protection for the eagles that only the Endangered Species Act can provide. 
12 week old bald eagle
Photo by Matt Lewis
A 12-week old bald eagle explores the area around the nest. Eaglets typically start flying at around 15 weeks, and don’t get the white head feathers for about three years.
The Arizona Game and Fish Department supports viewing the population as distinct, but concludes the eagles are in no immediate danger even though they have been delisted, Jacobson said.

“Even though we are delisting, we are going to continue these positive actions for bald eagles,” Jacobson said, referring to the Nestwatch program.  

Everywhere there is a known nesting site in the state, Game and Fish assigns a team of nest watchers to ensure that the breeding pair of birds has sufficient space without interference by humans. With support from land management agencies and the Heritage Fund, the department hires nest watchers to monitor the status of all nest sites.  From February until May, they keep a daily log of all movements and activities of the eagles and any other animals in their buffer area, and report that information to Game and Fish, explained Leah Vader, a nest watcher at the Fort Mcdowell Yavapi Nation site.  

Robert Mesta, a biologist with the U.S. Fish and Wildlife Service, said the agency has substantial reasons for not finding the Sonoran bald eagle a distinct population segment.  He said that the population of bald eagles in North America as a whole has sufficiently recovered since the species was listed as endangered.  Agency officials have expressed concerns that relisting the bald eagle as endangered might lead the public to think that the Endangered Species Act is not effective, Mesta said.  He cited examples, such as the peregrine falcon, of species that have recovered as a whole population but are still struggling in certain areas. 

The U.S. FWS decision, however, has created some turmoil within the agency that is creating discord among employees.  Many Fish and Wildlife employees in the state side with the Center for Biological Diversity and the Arizona Game and Fish Department regarding the issue. The lawsuit challenging the Fish and Wildlife Service’s decision in the fall not to make the Arizona eagles a distinct population segment is expected to go to court in the spring.

The Center for Biological Diversity hopes to win the lawsuit because they want to ensure that the bald eagle’s habitat is fully protected, Silver said.  Silver called Kenneth Jacobson “a hero for the eagles” because of continued efforts to monitor and protect the bald eagles.  But Silver calls on the Fish and Wildlife Service and the politicians in Washington “to obey the law and protect our unique and special, imperiled population.”


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