(Image from San Elijo Lagoon Conservancy, sanelijo.org)

The California gnatcatcher, the little blue-gray songbird that sounds like a kitten, may come off the U.S. Fish & Wildlife Service's list of threatened and endangered species — a result of a series of DNA tests that found the few American birds have the same DNA as the abundant Baja California gnatcatcher.

The Pacific Legal Foundation, which represents two groups of property owners, last June submitted a petition to delist the birds to the U.S. Fish & Wildlife Service. The California Building Industry Association and the National Home Builders Association cosponsored the petition. The comment period opened December 31 and ends March 2.

"Tens of thousands of acres of land have been designated as critical habitat in California," said legal foundation attorney Tony Francois. "The [federal] service itself estimates that by 2025 steps taken to protect the bird will have cost Californians $1 billion in land-use decisions."

This is the group’s second push at delisting the California gnatcatcher, which is listed as a distinct subspecies of gnatcatcher, separate from the Mexican bird with the same name.

Five years ago, the legal foundation submitted the findings of professor Robert Zink of the University of Minnesota, who examined and compared the mitochondrial DNA of the California gnatcatcher to that of the Baja gnatcatcher. Zink, a biologist who has won grants from the National Science Foundation, concluded that the California and Mexico birds were not genetically separate and distinct.

After a Fish and Wildlife review of the DNA evidence, the federal service denied the petition and said that nuclear DNA comparison would be more accurate, according to Francois. So, Zink went back to work and found the nuclear DNA of the California and Mexican birds were not distinctly different. Then, the federal service accepted the petition.

For Andrea Jones, director of bird conservation for the Audubon Society and a biologist, the fight over the potential delisting has consequences beyond the gnatcatcher — though the gnatcatcher will certainly be affected.

"Coastal scrub sage is one of the most endangered habitats on Earth, and if we lose the gnatcatcher, we lose the ability to protect this habitat that protects so many other birds," Jones said.

When the Fish and Wildlife comment period ends on March 2, according to Mendel Stewart. the agency will solicit a third party to look at the science and the arguments.

"Our job is now to gather unbiased information about the scientific rigor of these studies," Stewart said. "Then we will take that information and make our own decision."

At the heart of the decision is the question: what defines a subspecies? The arguments will focus on some combination of genetics, how the birds appear (morphology), and the geographic separateness of the various gnatcatchers, Stewart said.

"Some people are lumpers and some people are splitters," Stewart said.

Francois says the petitioners are guardedly optimistic they will be able to bump the bird off its costly perch.

"They have to take the best available science — they can't endlessly issue people homework," Francois said.

Meanwhile, the Audubon Society says that the science can't be trusted, since it was purchased with building-industry money.

"Researchers we have faith in have discredited the science," said Audubon spokeswoman Daniela Ogden. "They should not have used genetic markers to determine the subspecies."

California gnatcatchers were declared a subspecies of gnatcatcher (Polioptila Californica) in 1991, based mainly on their appearance. The underlying research — which relied in part on paint-wheel identification of color of taxidermied birds, wasn't made public for years and was later partly repudiated by the scientist who did it, according to the legal foundation.

In 1993, the subspecies made the threatened and endangered list, despite differing opinions from respected scientists who supported and opposed the listing — a relatively common occurrence, all sides agree.

Since then, the subspecies' presence in coastal sage scrub has triggered countless legal actions and imposed building and land-use restrictions throughout Southern California, from Ventura County to the Mexican border.

That, says Audubon spokeswoman Ogden is what is driving the move to delist the California gnatcatcher.

"The developers want to build in the coastal sage scrub habitat, so they over-emphasized the negative and ignored the positive," Ogden said. "If they succeed in this argument, they will go after other listed species."