The U.S. Fish and Wildlife Service has completed its review of an Endangered Species Act (ESA) petition to delist the Bone Cave harvestman, an eyeless relative of the spider found only in two Central Texas counties. Based on this review, the Service finds that the Bone Cave harvestman should remain listed as an endangered species under the ESA and the petitioned action is not warranted at this time.
A review of the best available scientific and commercial information regarding the past, present, and future threats to the species indicates that the Bone Cave harvestman is in danger of extinction throughout its range and meets the definition of an endangered species under the ESA.
The Bone Cave harvestman occurs only in subterranean habitats of the Balcones Canyonlands in portions of Travis and Williamson counties. It depends on high humidity, stable temperatures, and nutrients derived from the surface.
The species was listed as endangered in 1988, primarily due to habitat destruction and fragmentation from increasing urbanization in the rapidly growing Austin-Round Rock metropolitan area. Projected human population growth estimates for both Travis and Williamson counties indicate substantial increases will continue over the next several decades.
On June 2, 2014, the Service received a petition requesting that the endangered Bone Cave harvestman be delisted due to recovery and error in information. On October 10, 2019 the Service published a 90-day finding in the Federal Register that the petition presented substantial scientific or commercial information indicating that delisting the Bone Cave harvestman may be warranted.
Under the ESA, the Service is required to make a finding whether or not a petitioned action is warranted within 12 months after receiving any petition for which we have determined contains substantial scientific or commercial information indicating that the petitioned action may be warranted. This “not warranted” decision represents the Service’s 12-month finding.
The Service’s findings are based on a recently completed Species Status Assessment of the species and include input and review from academia, state agencies, species experts and others. The in-depth review of the species’ taxonomy, habitat, stressors, and resources needed to maintain long-term persistence can be found here.
A notice of the not warranted finding on the petition to delist the Bone Cave harvestman can be found in the Federal Register.
