Effects of livestock removal and perennial grass recovery on the lizards of a desertified arid grassland

We sampled lizards inside and outside of a 9.3 ha livestock exclosure in a desertified arid grassland in southeastern Arizona with pitfall traps and mark-recapture. Lizard community composition was significantly different inside versus outside of the exclosure. Analysis of tail-break frequencies suggests that higher predation rates outside the exclosure may contribute to increased abundance of Sceloporus undulatus and Uta stansburiana following livestock removal and associated changes in grass cover and vegetation complexity. In contrast, Phrynosoma modestum was significantly less abundant inside the exclosure. These results indicate that lizard abundance can increase and community composition can change in desertified arid grasslands following livestock removal that results in increased grass cover and vegetation complexity.