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Contrasting management paradigms for pronghorn in the arid Southwest and their northern range: a review

William T. Bean, H. Scott Butterfield, Craig Fiehler, David Hacker, Jeanette K. Howard, Russell Namitz, Brandon Swanson, Thomas J. Batter

TNC launched a Water for Wildlife project motivated by understanding the importance of standing free water across the season for wildlife in general, but most importantly for those species sensitive to water availability during times of the year when water is typically limiting in California, including the iconic pronghorn. Pronghorn exist in only a few small, isolated populations in California, including in the Modoc Plateau and within the greater Carrizo Plain. A species that used to exist more broadly across the Central and San Joaquin Valleys and down in to and through the Sonoran Desert has seen its populations plunge, originally due to over hunting and habitat loss and fragmentation, but now potentially because of reduced free standing water and forage during critical time periods, including fawning. Climate change, groundwater pumping, and continued habitat fragmentation are also negatively impacting pronghorn populations in California and the southwest US. This review, a first of its kind in more than 20 years, systematically reviewed the pronghorn literature across the western U.S. to better understand what drives pronghorn populations dynamics, including reproduction, fawning, and adult survival, and based on those findings how we can reconstruct important landscape attributes (including year-round free-standing water and forage) to support healthy sustainable pronghorn populations in California. TNC, in partnership with CDFW, BLM, Cal Poly, and other partners, has recently launched a Water for Wildlife strategy focused on developing new water sources – specifically designed for wildlife, like pronghorn and tule elk – across the Carrizo Plain and other land holdings within the San Andreas Linkage, and testing whether water, in combination with more connected landscapes that provide year-long forage, leads to larger, healthier wildlife populations.