Interrelationships among Calling Effort, Growth Rate, and Chorus Tenure in Bufo fowleri

Abstract

Abstract A population of Fowler's toads, Bufo fowleri, was studied between 21 April and 20 June 1992 in Medford, NJ. I obtained records of body size, body temperature, and focal samples of calling activity from 126 males over two months of chorus activity. Assuming that vocalizing is energetically costly, my primary purpose was to investigate whether calling effort was correlated with body size, growth rate, or chorus tenure. In addition, given that the body temperature of calling males over the breeding season varied by more than 10 C, these data provided an opportunity to identify correlations among body temperature and measurements of calling behavior. I made focal observations of calling activity on 16 nights. Mean nightly calling efforts were relatively constant throughout the study (range 10.8–14.2 sec of vocalizing per minute) with only 4% of the variation in individual calling effort explained by body temperature. Individual calling effort was weakly positively correlated to body size. Males tende...