This week we filed our final trial court brief in our challenge to the Endangered Species Act listing of the coastal California gnatcatcher. We argue that the gnatcatcher should not be listed as a distinct “subspecies.” The Service and the environmental intervenors contend that the listing should be upheld because the Service used the best available data to affirm the gnatcatcher’s separate subspecies status. But as our reply brief explains, this evidentiary defense misses the point: whatever the value of any particular study or set of data, the Service must still articulate and apply to the data a standard for subspecies diagnosis. Here, the Service failed to do that, instead simply citing “differences” between the coastal California gnatcatcher and other plentiful gnatcatcher populations in Mexico. But that defense fails too, because the purported “differences” are so slight that one could, using that standard of difference, arbitrarily propose any number of overlapping gnatcatcher subspecies.
Briefing in the case will be complete by the end of October, and we hope for a decision not too long thereafter.