Arizona's bald eagles maintained recent population gains during the 2010 breeding season, but conservation groups say the birds' success could falter if a judge strips them of their endangered-species status.
The number of breeding adult eagles grew to a record 104 this year, up from a previous high of 100, the Arizona Game and Fish Department reported Monday. Three new active breeding areas were found.
By the end of the breeding season, which typically starts in December and continues into mid-summer, 44 eaglets took their first flight from the nest, or fledged, a critical step toward their survival in the wild. That number is down slightly from 2009, but up significantly from 2000, when 23 birds fledged.
Biologists watch not only the number of birds that hatch and fledge, but also the number of locations where breeding pairs nest. The number of occupied breeding areas grew to 52 this year; there were 38 occupied areas in 2000.
"Identifying three new breeding areas in the state is a positive sign that our population of bald eagles continues to grow and do well," said Kenneth Jacobson, the state wildlife agency's bald-eagle-management coordinator.
Arizona's desert-nesting bald eagles remained protected under the federal Endangered Species Act, even after the U.S. Fish and Wildlife Service removed the eagle from the endangered list in 2007.
Conservation groups sued the government over its decision, arguing that the bald eagle, found almost exclusively in Arizona, was a distinct population segment that had not recovered to the same degree as eagles elsewhere in the United States.
A federal judge ordered the wildlife service to reconsider its findings, but the agency reaffirmed its decision earlier this year, concluding that the Arizona eagle is not important enough biologically to retain its protection.
The judge heard a final round of arguments on the case on Sept. 14 and could issue a final decision at any time.
If the judge dismisses the case and allows the delisting decision to stand, conservation groups say they will file a new lawsuit. Although other state and federal laws will protect the eagles, only the Endangered Species Act protects the birds' nesting habitat.
"This is a population that's been important, significant and critical to our wildlife enjoyment and our culture here," said Robin Silver, who follows the issue for the Center for Biological Diversity, a Tucson-based advocacy group. "The new numbers don't change the fact that this is a population that's in trouble."