Diet Selection by a Lizard Ant-Specialist in an Urban System Bereft of Preferred Prey

Abstract Habitat loss, land-use transformation, climate change, and biological invasions all elevate the importance of plasticity in food selection for the continued persistence of dietary specialists. Horned lizards (Phrynosoma spp.) are myrmecophagic specialists and the abundance of ant prey make their populations vulnerable to habitat loss, as well as invasive ants and associated pest control programs. We studied ant use by Phrynosoma cornutum (Texas Horned Lizards) on an insular urban reserve in central Oklahoma that was bereft of harvester ants (Pogonomyrmex spp.), presumed to be their chief prey. The five most commonly available ant genera based on bait station captures were Monomorium (69%), Forelius (11%), Pheidole (10%), Crematogaster (7%), and Tapinoma (2%). Based on the examination of 124 scat samples from adult and juvenile P. cornutum, Crematogaster (81%), Pheidole (12%), Formica (6%), and Monomorium (1%) were used as prey. Consumption of prey in several ant genera by P. cornutum disproportio...