Meeting Abstract

41.3  Tuesday, Jan. 5  Metabolic Rates and Movements of Male Tarantulas During the Breeding Season STOLTEY, T*; SHILLINGTON, C; Eastern Michigan University; Eastern Michigan University tstoltey@gmail.com

Tarantulas (Araneae: Theraphosidae) exhibit sexual dimorphism in their resting metabolic rate (RMR). The significantly higher RMRs observed in sexually mature males may be an adaptive strategy to support increased energetic demands imposed by mate searching. In this study, we investigated how intra-sexual differences in male RMR may affect their locomotory activity and behavior during the breeding season. Over a 2-year period, we radio-tagged males, measured their movements, and periodically recorded their metabolic rates in an open-flow respirometery system over the course of the breeding season. Differences found in search speed, search area size, and movement patterns were not sufficiently explained by the small amount of intrasexual variation exhibited in RMR. Individuals were capable of searching areas up to 29 hectares and moved up to 365 m/day. In addition, metabolic rate measured over a 24-hr period showed no circadian periodicity and remained constant over the season. Lastly, the body condition of new captures stayed constant throughout the season, corroborating observations of males feeding and drinking.