Thursday, December 07, 2006

No Listing for Cerulean Warbler

The US Fish and Wildlife Service has declined to list the cerulean warbler under the Endangered Species Act. Conservation groups had asked the government to list cerulean warblers in 2000; the FWS began a status review in 2002. The decision announced this week was based on a review of data and petitions submitted as part of a public comment period.

Although there is no precise estimate of the current abundance of the cerulean warbler, the Service used a 1995 population estimate of 560,000 warblers during its review of the species’ status. Based on 40 years of data obtained through the Breeding Bird Survey which indicates the population is declining at about 3 percent each year, the estimated population in 2006 would be approximately 400,000. At this rate of decline, the Service estimates the cerulean warbler population would number in the tens of thousands 100 years from now.
The FWS does plan to maintain some involvement in conservation efforts, as is noted in the press release linked above. The decision not to list removes some of the legal muscle that would assist conservation efforts. I can understand the decision to focus on species in greater trouble, but I have to wonder whether assuming a steady rate of decline is valid. The response by the Southern Environment Law Center notes that recent estimates of rate of decline have indicated an increase to a 6% decline each year.
The Fish and Wildlife Service failed repeatedly to meet federally mandated deadlines under the Endangered Species Act for responding to the petition. In the intervening years, scientists believe the bird's annual rate of decline increased from 4% to 6%, and threats to its habitat have worsened. ...

The Cerulean population has dropped almost 82% throughout its U.S. range over the last 40 years, making it the fastest declining warbler in the country. ... Once common, it has grown increasingly rare as forest habitat in both hemispheres has been destroyed and fragmented by logging, surface mining and development. In the U.S., the worst of the Cerulean's decline has been in the core of its range - 80% in the Cumberland Plateau in Tennessee, Kentucky and West Virginia, and 65% in the Ohio Hills in Ohio, West Virginia and Pennsylvania.
I have some comments about cerulean warblers in an older post.