Meeting Abstract
Given low primary productivity and the constraints of high heat and predators in deserts, then maximizing energy intake when foraging is presumed to be an imperative for desert lizards. Ants are the primary prey of the Desert Horned Lizard, Phrynosoma platyrhinos in a northern portion of the Great Basin desert scrub. The largest and most abundant ant species in the studied locale is the harvester ant Pogonomyrmex californicus, but this local ant species uniquely harbors a putatively harmful nematode parasite of P. platyrhinos. Hence, one could reasonably predict that energetics may not be the only factor in diet choice in this lizard. Moreover, reduced proportions of P. californicus in P. platyrhinos diets are expected in food-lean years relative to food-rich years because expansion of the diet to energetically less-preferred ants is expected in food-lean years. The foregoing ideas were examined using a variety of data sets over a 10 year period. These data sets included several methods of assessing spatiotemporal patterns of ant availability and analyses of the diet of P. platyrhinos, along with such outcomes as individual lizard body condition and annual recruitment into the lizard population.
