A late Pleistocene nest cave of Gymnogyps californianus (California Condor) in Texas: New radiocarbon and stable isotope analyses.

This article focuses on the reexamination of late Pleistocene fossil remains of Gymnogyps californianus (California Condor) from Mule Ears Peak Cave in Big Bend National Park, Texas, to establish precise evidence of nesting and diet in this region. Radiocarbon dating of juvenile condor bones confirms nesting occurred around 13,000 calendar years before present, with condors present from approximately 15,000 cal yr BP until their extirpation at the end of the Pleistocene, likely linked to megafaunal extinction. Stable isotope analyses indicate these condors fed on megafauna adapted to C4 desert grassland plants, consistent with other inland western populations. The findings support considering Big Bend National Park as a potential release site for captive-reared condors in ongoing recovery efforts, given its suitable habitat and historical significance as a nesting area.