Desert Tortoises in Zion National Park Represent a Natural Extension of Their Range

Abstract. The northeastern extreme of the Mojave desert tortoise (Gopherus agassizii) distribution near Zion National Park in Utah is contested as a natural range limit because of its suboptimal habitat and known anthropogenic movements of tortoises. In this study, we added microsatellite data from nine tortoises from the Zion area to a previously published population genetic analysis to determine the tortoises' likely origins. Our results suggest that both anthropogenic tortoise movements and descendants of local tortoises make up the individuals found near Zion.