Endangered Species Law & Policy

On April 13, 2010, the Pacific Legal Foundation (PLF) filed a petition (PDF)  to remove the coastal California gnatcatcher, specifically, the subspecies Polioptila californica californica, from the Fish and Wildlife Service’s list of threatened species. Considerable controversy surrounded the 1993 listing and subsequent designation of critical habitat for the coastal California gnatcatcher because its range includes prime real estate and agricultural land in the southern California counties of Los Angeles, Orange, San Diego, Riverside, and San Bernardino.

In its petition, PLF argues, in essence, that scientific studies indicate that no such subspecies exists, i.e., there is no such thing as the coastal California gnatcatcher. PLF cites scientific studies published since the 1993 listing that undermine the original basis for the listing. The decision to list the gnatcatcher relied heavily on research published in the early 1990s indicating that the relatively small population of gnatcatchers in southern California formed a subspecies of the much larger population of California gnatcatchers that extends from Los Angeles to the southern end of Baja, Mexico. But studies based on genetic analysis and re-analysis of the original data set that led to the listing conclude that there is no biological basis for the P. c. californica taxonomic classification. If there is no such subspecies, then, according to PLF, the gnatcatcher is not threatened because the larger population inhabiting southern California and Baja, Mexico is not vulnerable to extinction in the near future.

If the Fish and Wildlife Service delists the gnatcatcher, the designation of nearly 200,000 acres of land as critical habitat will be withdrawn. Delisting, however, would not result in the removal of all regulatory protections for the gnatcatcher in southern California. Much of the coastal California gnatcatcher’s range is already subject to conservation under the terms of Habitat Conservation Plans that collectively cover millions of acres, and the gnatcatcher is also protected under the Migratory Bird Treaty Act. Accordingly, delisting may have little or no practical effect for many landowners and developers in the region.

It is possible that the Fish and Wildlife Service could deny the petition if the Service designates the population of gnatcatchers in southern California a Distinct Population Segment (DPS). Indeed, it has been considering such a DPS designation since 2003. But PLF’s petition cites an scientific article in which the authors conclude that not only is there no scientific basis to consider the gnatcatcher population in southern California a subspecies, there is also no basis to consider the population an Evolutionarily Significant Unit (ESU), which would undermine the argument that it forms a DPS.