Seasonal and stress related changes in plasma gonadotropins, sex steroids, and corticosterone in the bullfrog, Rana catesbeiana

Studies of seasonal gonadal cycles combined with direct measurements of plasma levels of the two gonadotropins (FSH and LH), several gonadal steroids (estrogen, E; progesterone, P; testosterone, T; and 5 alpha-dihydrotestosterone, DHT), and the interrenal steroid corticosterone (B) were made in male and female bullfrogs in central California over a 5-year period (between 1976 and […]

Analyzing acoustic interactions in natural bullfrog (Rana catesbeiana) choruses

Analysis of acoustic interactions between animals in active choruses is complex because of the large numbers of individuals present, their high calling rates, and the considerable numbers of vocalizations that either overlap or show close temporal alternation. The authors describe a methodology for recording chorus activity in bullfrogs (Rana catesbeiana) using multiple, closely spaced acoustic […]