Field and laboratory responses to drought by Common Side-blotched Lizards (Uta stansburiana)

Starting in 2012, and peaking in 2013, drought conditions in the Great Basin Desert persisted for almost four years. By studying a meta-population of Common Side-blotched Lizards in the wild, we found that a failure of spring rains correlated with a marked reduction of body condition in female, but not male, lizards. Likewise, rainfall correlated with reproductive scores of females such that a failure of spring rains in 2013 resulted in a cessation of the breeding season. By 2014 it was apparent that the drought had caused a general failure of recruitment into the population, which affected the body-size distribution of lizards for several subsequent years. To disentangle the effects of both water and food availability during a drought, we next conducted a laboratory experiment by imposing a drought on breeding animals, but not otherwise limiting food. Results indicate that the absence of drinking water alone tends to delay the breeding season as well as cause reproductive failure in females even as body condition was maintained. Our combination of field and laboratory data reveal that body condition and reproductive responses to drought are not strictly about food limitations, but are also caused by a lack of available drinking water.