Date of Award


Publication Type

Master Thesis

Degree Name



Biological Sciences

First Advisor

Mennill, Daniel

Second Advisor

Doucet, Stephanie


Acoustic communication, Animal behaviour, Anuran, Incilius luetkenii, Sexual dichromatism, Visual communication




Frogs and toads use both acoustic and visual signals to communicate within their noisy, competitive breeding aggregations. In this thesis, I studied acoustic and visual signals in the Neotropical yellow toad, Incilius luetkenii, in Costa Rica. I provide the first quantitative description of this species’ vocal behaviour, and I demonstrate that the spectral properties of male calls are correlated with body size; therefore, male calls may be used in size assessment. I experimentally demonstrate that chorus transmission distance is enhanced by the number of concurrently calling toads as well as the pitch of their calls; therefore choruses may attract more conspecific animals than a lone signaller. In terms of visual signals, I show that males respond more strongly to female-like brown models versus male-like yellow models; therefore colour facilitates sex recognition. My research expands our understanding of communication in a scramble competition mating system of an explosively breeding anuran.