Patterns of lizard species richness within National Parks and Biosphere Reserves across North America's deserts

• Our research addresses the biogeography of indigenous desert lizards of the US and Mexico.
• We identified 110 lizard species within the conservation lands network in the US and Mexico deserts.
• 3 “hot spots” of species richness and 2 centers of narrow endemism were identified.
• Species richness was correlated with topographic diversity and numbers of endemic species.
• These findings are a framework for future analyses to identify site-specific conservation needs

Warm deserts world-wide provide habitats for rich lizard species assemblages; North American deserts are no exception, however the desert regions of the US and Mexico are experiencing increasing habitat changes from multiple anthropogenic sources. Our objective here was to document current lizard species richness patterns across the North American deserts within the existing network of conservation areas. We identified 110 lizard species occurring across one or more of the 19 sites we analyzed. Three species richness hot spots were identified; a northern Baja California faunal extension into southern California in the US, and in Mexico, two sites within the state of Coahuila, as well as high endemism in the Cape Region of Baja California Sur. Species richness was associated with sites where desert ecoregions overlap and with insular isolation. Our uncertainty regarding how species will respond to the multifaceted aspects of global change is such that large protected natural areas with complex topography may be the most effective strategy for protecting desert lizards along with overall biodiversity. The 19 sites we analyzed represent the cores of a more robust conservation network that will be needed for the protection of biodiversity across North American Deserts.