A Reexamination of the Herpetofauna of Oaxaca, Mexico: Composition Update, Physiographic Distribution, and Conservation Commentary.

A substantial number of changes to the composition of the herpetofauna of the Mexican state of Oaxaca, including taxonomic additions and deletions, have occurred in the five years since our original assessment of this region. These changes now establish a herpetofauna of 480 species for the state. A number of taxonomic and nomenclatural changes involving the Oaxacan herpetofauna also are discussed. Updated patterns of physiographic distribution, endemism, and conservation status of the members of the state herpetofauna are examined.

Effects of human-made resource hotspots on seasonal spatial strategies by a desert pitviper.

Habitat heterogeneity and local resource distribution play key roles in animal search patterns. Optimal strategies are often considered for foraging organisms, but many of the same predictions are applicable to mate searching. We quantified movement and space use by a pitviper to test whether Native Habitats (NH) and human-made Resource Hotspots (RH) facilitate alternative seasonal spatial strategies as a result of critical resources, including potential mating partners, being widely dispersed in NH and clustered in RH. Independent of habitat category, seasonal patterns resembled an intermediate mating system with elements of prolonged male mate-searching and female-defense. However, individuals using primarily NH or RH exhibited alternative strategies. NH rattlesnakes displayed greater movement and larger home ranges than RH rattlesnakes across behavioral seasons. NH males increased movement distances and home ranges during the mating season, while RH males displayed minimal or no seasonal shifts. NH females also elevated movement distances during the mating season, while RH females showed no significant seasonal differences. Despite contrasting spatial patterns, mating success and female-defense effort were not significantly affected by habitat category. This unique study system highlights the potential for interactions among sexual selection, habitat heterogeneity, and behavioral plasticity to facilitate divergent search tactics within populations.