The Texas General Land Office (GLO) and the Texas Public Policy Foundation (TPPF) are suing the federal government because the golden-cheeked warbler has not been removed from the endangered species list.

The lawsuit filed last week follows a similar 2017 lawsuit the GLO and TPPF filed to have the bird delisted. The original case ended on appeal in 2020 when the Fifth Circuit court of appeals ordered the federal government to revise its process for determining endangered species. The new lawsuit alleges the federal government never did that. 

The 2017 lawsuit cited a 2012 study by Texas A&M researchers that found a population of 263,000 male warblers, almost ten times more than the 27,000 the U.S. Fish and Wildlife Services currently lists as their population size. 

“The time has come to remove the golden-cheeked warbler from the endangered species list,” the 2017 lawsuit reads. “Delisting this species is now compelled by today’s best available science.”

According to its website, the Texas GLO manages state-owned lands and mineral rights totaling 13 million acres. According to Ted Hadzi-Antich, a senior attorney with the Texas Public Policy Foundation and the lead counsel on the warbler case, the Texas GLO is the most impacted by the golden-cheeked warbler’s presence on the endangered species list.

The GLO is affected by restrictions placed on land considered warbler habitat, which lower the market value of property. Hadzi-Antich spoke with the Texas Tribune and used a 2,300-acre parcel of land between Bexar and Kendall county as an example. About 85% of the parcel is considered the warbler’s habitat, limiting what can be developed on the land and decreasing property value by 35%. 

“They wanted to develop that property, but with this diminution in value, that became problematic,” Hadzi-Antich said. “Nobody wants to see species become extinct. The problem is, you’ve got palpable adverse impacts on humans from some of these requirements.”

However, researchers that worked on the 2012 Texas A&M study did not intend for their final results to be used in arguments for delisting the bird or removing its habitat protections.  

“Rather,” said Heather Mathewson, the lead researcher, “this study is one of many necessary steps in our evolving knowledge of the golden-cheeked warbler, [It] is not intended as the final word on the matter.”

The golden-cheeked warbler is a small migratory songbird, characterized by a bright yellow face and distinct black marks. Its habitat ranges across 35 counties in Texas, from west of San Antonio northward up to the Dallas-Fort Worth metroplex. The bird lives mainly in central Texas along Interstate 35, a rapidly-growing region facing an increasing demand for new housing developments. 

The U.S. Fish and Wildlife Service first added the bird to the endangered species list in 1990; the primary reason for its addition was the threat of habitat loss. 

The U.S. Fish and Wildlife Service argues the golden-cheeked warbler should remain protected for the same reason. A 2013 study found that between 2001 and 2011, the warbler’s habitat was diminished by 29% due to the rapid development of suburbs outside of Austin and San Antonio. 

“These efforts represent new estimates rather than indicators of positive trends in warbler habitat and population size, and thus do not imply recovery,” the Fish and Wildlife Service wrote of the 2012 Texas A&M population study.

Further, Roel Lopez, director of Texas A&M’s Natural Resources Institute, noted that research methods in 1990, when the government first added the bird to the endangered list, were much less accurate. There is no way to know for sure what the warbler’s population was in 1990 and if its population has decreased or increased since then. Lopez said that the 2012 researchers used vigorous methods and the most current technology available to determine the population estimate. 

“The methods back then [in 1990], when the warbler was first listed [as endangered] may not have been as robust, or there wasn’t a lot of information,” Lopez said. “Through time, there may be an increased effort to survey and sample more, so it’s not uncommon for us to work on a species and — through an increase in effort — actually find more of them.”

Michael Morrison, a professor at Texas A&M and biologist who worked on the 2012 study, says the arguments are focused on the wrong issue. 

“We need to be focusing on working with landowners to maintain large continuous tracts of habitat, give them tax breaks, and reasons to maintain that,” Morrison said. “Fighting over whether or not there are 100,000 or 200,000 birds, to me, is kind of not the point.”