George H. Dalrymple

Seasonal activity and road mortality of the snakes of the Pa-hay-okee wetlands of Everglades National Park, USA

Abstract The composition and activity of the snake community of the Pa-hay-okee wetlands of Everglades National Park is described. The study was conducted in February and March 1986 and from February 1987 to January 1989. A total of 1172 individuals of 16 taxa were observed, with Thamnophis sauritus, T. sirtalis, Nerodia fasciata pictiventris and Agkistrodon piscivorus representing 89·2% of the total sample. The seasonal activity of the snakes was closely related to fluctuations in the water table. Periods of greatest snake activity coincided with the periods of greatest human visitation. Seventy-three percent of all snakes observed on the parks main road were either injured or dead. Management recommendations are provided to minimize loss.

Seasonal Activity of the Snakes of Long Pine Key, Everglades National Park

We found 20 species of snakes in the Long Pine Key region of Everglades National Park. From 1984-86, data were obtained on 1782 snakes. Peak activity occurred during the wet season from May-Oct. We analyzed activity of the nine most common species in detail. The overall pattern was bimodal; captures peaked in early summer and fall. Coluber constrictor, Diadophis punctatus, Opheodrys aestivus, and Thamnophis sauritus were most common in early summer (MayJuly). Sistrurus miliarius was most common in fall (Oct.). Elaphe guttata, E. obsoleta, Storeria dekayi, and T. sirtalis had two or more peaks of activity. Species samples were broken down into adult males, females, and non-adults (juveniles plus young-of-the-year [YOY]). Males were more common in the samples of C. constrictor, E. guttata, E. obsoleta, and Sistrurus miliarius. Females were more common in D. punctatus, 0. aestivus, Storeria dekayi, and T. sirtalis. Both sexes were equally common in T. sauritus. Juveniles and YOY were especially common in the fall in E. obsoleta, Storeria dekayi, T. sirtalis, and Sistrurus miliarius, and contributed significantly to a second peak in numbers. Individuals of many species were encountered at varying frequencies over all 12 mo in a year. Since activity patterns and/or relative abundances for the subgroups were different in most species, we conclude that activity curves for snake species that do not include data on sex and age may be of limited value for study of phenology and reproductive ecology. Data on hatching and birth dates are presented, and when taken with activity data reveal only moderate alteration of typical temperate zone patterns of reproduction and activity in this subtropical region.

Management of an endangered species of snake in Ohio, USA

Abstract More species of snakes are becoming endangered yet information on their effective management is lacking. The present study assessed the general biology of the prairie garter snake, an endangered species in Ohio, USA, and the potential impact of mortality due to game management practices in a state wildlife area (automobile traffic and grass mowing operations). Alterations to the present management practices include alternatives such as rescheduling of mowing operations to coincide with the snakes periods of inactivity and using signs to caution motorists to avoid hitting snakes on the road. Future management of wildlife areas should not focus upon a single species or trophic level but rather consider both non-game and game species.