WASHINGTON (CN) – The Sonoran Desert population of bald eagles is not a distinct population segment and may not be protected under the Endangered Species Act, the U.S. Fish and Wildlife Service has determined, again.
The USFWS removed all bald eagles in the lower 48 states from the list of threatened and endangered species in 2007 claiming that the species had fully recovered under protection of the act.
The Sonoran desert population was excluded from the delisting by a court order after conservation groups and Native American tribes successfully challenged a 2004 decision by the USFWS that the Sonoran population did not meet the definition of a distinct population segment (DPS).
Under USFWS and National Oceanic and Atmospheric Administration Fisheries Service policies, a population of a species may be designated a distinct population segment if it is discrete from the general population, and if its survival is significant to the species.
In 2008, the U.S. District Court in Arizona ordered the USFWS to conduct a 12-month status review to reconsider its previous decision. In February 2010, the USFWS completed its review, sticking by its previous conclusion that while the desert eagle population was discrete from the larger population it was not significant to the species.
By October 2010, the Center for Biological Diversity and the Maricopa Audubon Society were back in court arguing that the USFWS had ignored significant evidence that the dry land bird was different from other bald eagle populations and that policy mandated from Washington D.C. ran rough-shod over science in Arizona.
In December 2011, U.S. District Judge David Campbell agreed, set aside the 2010 12-month review and ordered the USFWS to complete a new study by April 2012.
Campbell allowed the USFWS to conduct the new review based on information gathered in its previous attempt and ordered the service to determine if it had adopted a new interpretation of the DPS policy and to justify why loss of the desert eagle would not lead to a significant gap in the range of bald eagles.
This time around, the USFWS also found that the desert eagles were discrete from, but not significant to, the general bald eagle population.
The USFWS insisted it did not employ a new interpretation of the DPS policy, and detailed each step of its analysis consistent with congressional guidance that DPS listings be used “sparingly.”
“Significance” boils down the impact on the species if the discrete population were lost.
Because Sonoran eagle breeding pairs represent less than one percent of the total breeding pair population in the lower 48 states and much less than half of one percent when the breeding pairs in Canada and Alaska are included, the USFWS says loss of the entire population would have negligible impact on the species.
The review also found that the desert eagles were neither genetically distinct, nor particularly adapted to their environment in ways that were vital to the larger population.
As for the land itself, the review determined that the actual amount of suitable habitat in the Sonoran desert is minute relative to the habitat available to bald eagles throughout their range, and that it plays no particularly important role in the life history of the species.
Even if the desert eagles were eligible for listing as a DPS, the USFWS found that none of the threats it faces pose a significant risk of extinction to the population.
In fact, the service found that, by every demographic category, the Sonoran eagle population is on par with populations delisted in 2007. So listing it as threatened or endangered would not be warranted.
While bald eagles are no longer listed as threatened or endangered under the Endangered Species Act, they are protected by the Bald and Gold Eagle Protection Act and the Migratory Bird Treaty Act, which prohibit anyone from hunting the birds, taking their feathers, eggs or nests without a permit issued by the Secretary of the Interior.