Surface activity of the San Diego horned lizard, Phrynosoma coronatum blainvillii

The San Diego horned lizard, Phrynosoma coronatum blainvillii, is a large, myrmecophagous lizard that occurs from northwestern Baja California, Mexico, into the coastal and inland regions of California from sea level to ca. 2,000 m. This is the first systematic field study of P. c. blainvillii, and our purpose is to describe its surface activity. Specifically, we provide data on temporal (daily and seasonal), gender, and age-class activity patterns, and how these patterns relate to this lizard's thermal and structural environment.