Population structure, body mass, activity, and orientation of an aquatic snake (Seminatrix pygaea) during a drought

Abstract

Juveniles comprised 89% of swamp snakes at the N-central Florida pond. Females were generally longer and weighed more than males. The sex ratio of snakes with a snout-vent length >150 mm was 1:1. Activity occurred throughout the year but peaked during summer. Hydroperiod and weather conditions did not appear to influence snake activity. During the latter years of the study, a regional drought that began in the mid-1980s became quite severe, but drought had little direct effect on overland migration or body condition but caused snakes to leave or to shorten the amount of time they spent within the pond basin. Snakes immigrated and emigrated nonrandomly; orientation was directed to and from the nearest large water body. Certain temporary ponds may comprise developmental habitat. The dynamic wet-dry climatic cycles in SE North America may lead to the formation of metapopulations in some aquatic snakes. -from Author