Nest Attendance by a Female Malayan Pit Viper (Calloselasma rhodostoma) in Northeast Thailand

Abstract

The function of egg attendance in pit vipers is understudied and poorly understood. Temperature sensitive radio telemetry was used to study nesting behavior and body temperature in a free ranging, female Calloselasma rhodostoma, which laid and attended a clutch of three eggs at a location in northeast Thailand. Oviposition occurred between 11 and 24 August, 2004 and all eggs had hatched by October 12, 2004 (incubation period = 49-62 days). The small clutch size was probably due to small maternal body size. The nest site was a rock crevice on a rocky, north facing slope, in mature deciduous dipterocarp forest. The female apparently remained coiled around the eggs for the entire incubation period with an average body temperature (Tb) of 27.1˚C (SD=1.61, range 23.7 to 30.4, n=60). Maternal Tb was slightly higher (1.5°C) than that of an operative temperature model in a similar, nearby microhabitat, suggesting an occurrence of a small amount of maternal thermogenesis. The female fed once during incubation and underwent ecdysis at or near the time the eggs hatched. Little parental care was observed beyond the time of hatching.