Steroid hormone profiles and relative body condition of calling and satellite toads: implications for proximate regulation of behavior in anurans

Current research in amphibians: Studies integrating endocrinology, behavior, and neurobiology

“…Social control seems capable of entraining calling rates once calling is enabled by adequate androgen levels . Interspecific variation in androgen control of calling may be a consequence of life history strategies such as expression of aggressive, territorial, or parental behavior (Townsend and Moger, 1987;Townsend et al, 1991;Emerson et al, 1993;Emerson and Hess, 1996;Leary et al, 2004), flexibility in seasonality (Houck and Woodley, 1995;Harvey et al, 1997), or energy required for the species-specific advertisement call (Emerson andHess, 1996, 2001;Leary et al, 2004). The contributions of other hormonal systems need also be considered, as do brain peptide neuromodulator systems.…”

“…In crested newts (Triturus carnifex) corticosterone levels are lower and androgen levels higher in inactive males than in actively courting males (Zerani and Gobbetti, 1993). In some anuran species, corticosterone is elevated in calling males compared to non-callers and does not seem to have an effect on androgen levels (Mendonça et al, 1985;Orchinik et al, 1988;Harvey et al, 1997;Leary et al, 2004). Emerson (2001) proposed the "Energetics-Hormone Vocalization" model to explain the confusing patterns in corticosterone and androgen levels in naturally behaving animals by incorporating energetic considerations (Fig.…”

“…Calling is reinstated when the male's energy reserve is restored, corticosterone levels are lowered, and androgen is elevated once again. Leary et al (2004) tested this model and found that although corticosterone was higher in calling males relative to non-calling satellite males in Bufo woodhousii and B. cognatus, androgen concentrations did not differ. Instead, in order to understand the transition between calling and non-calling behavior, the authors proposed a model that includes energy reserves, androgen and corticosterone concentrations, and direct actions of corticosterone on brain AVT neurons (Leary et al, 2004).…”

“…Leary et al (2004) tested this model and found that although corticosterone was higher in calling males relative to non-calling satellite males in Bufo woodhousii and B. cognatus, androgen concentrations did not differ. Instead, in order to understand the transition between calling and non-calling behavior, the authors proposed a model that includes energy reserves, androgen and corticosterone concentrations, and direct actions of corticosterone on brain AVT neurons (Leary et al, 2004). Future studies need to examine the interaction between these elements across species, and in both anurans and urodeles, in natural populations in order to understand the diversity of reproductive strategies and their neuroendocrine correlates.…”

Glucocorticoids in Mate Choice

“…Spectrophotometric measures of plumage suggested that dimensions of plumage colour and brightness provided cues to the stress status of the male. Similarly, in [42] Leary and colleagues found that female great plains toads (Bufo cognatus) preferred the calls of males with low glucocorticoids. There is growing evidence, then, that glucocorticoids play a role in mate choice.…”