| Agassiz's desert tortoises, Gopherus agassizii, face threats from a wide range of land uses within the California deserts, as well as from a warming and drying regional climate. Mitigation for tortoise multiple-use conflicts could entail habitat protection or translocation to avoid direct take of tortoises. Complicating this mitigation approach is that some areas now deemed suitable tortoise habitat will likely have reduced suitability as climate change effects become more pronounced. If we protect lands or translocate tortoises to currently suitable but potentially deteriorating habitats, are we adequately mitigating for habitat losses? Identifying climate refugia, habitats capable of sustaining tortoise populations even as climate change impacts become more pronounced, is a critical step. As a case study of how to address tortoise mitigation we employed habitat suitability modeling to identify current tortoise habitat and project where climate refugia will occur within and surrounding the U.S. Marine Corps Air Ground Combat Center (MCAGCC) at Twentynine Palms, California. We modeled nearly 284,000 ha of currently suitable tortoise habitat within an 858,800 ha study area. Projecting a possible +3°C shift in mean maximum summer temperatures by the end of the century, the area of tortoise habitat could be reduced 55% to 127,650 ha, however almost 115,800 ha would overlap current tortoise habitat and would be climate refugia. Without the tenuous assumptions of successful dispersal to new suitable habitat, these refugia represent high value conservation areas for current protection and, if required, for sites to translocate tortoises. Applied across the tortoise's range, this approach could focus and increase the efficacy of conservation for this threatened species. |