Hormonal control of behavioral sex differences in a tropical bird

January 3 – Febuary 28, 2021

Meeting Abstract

S12-2  Thu Jan 7 10:30 – 10:45  Hormonal control of behavioral sex differences in a tropical bird Schlinger, BA*; Chiver, I; University of California, Los Angeles and Smithsonian Institute, Panama; Smithsonian Institute, Panama schlinge@lifesci.ucla.edu

Hormones organize and activate brain and behavior in sex-specific patterns. Most studies of these phenomena utilize captive animal models and focus on pre-copulatory and copulatory behaviors. We have explored the role of Testosterone (T) in activating a variety of masculine behaviors associated with courtship under semi-wild conditions in the Golden-collared manakin (Manacus vitellinus). For these experiments, we established a large aviary situated within Panamanian rainforest with flora planted to resemble a natural Manacus leking environment. We treated non-breeding females and juvenile males with T and after one week released groups of 3 or 4 same sex birds into the aviary; behaviors were then recorded for at least 3 weeks. With or without T-treatment males cleared and defended courtship arenas, emitted courtship vocalizations and performed their elaborate courtship displays involving wing- & roll-snaps. T increased performance of all behaviors, in some cases dramatically. Females never cleared or claimed arenas and only with T did females perform very few if any wing- or roll-snaps and emit male-like vocalizations. T increased aggressive behaviors equally in males and females. Thus, some male typical behaviors were completely unresponsive to T in females, while others were partially responsive or fully responsive. Presumably, genetic or hormonal differences developmentally create some but not all behavioral neural circuits or create them in all birds but render them androgen-insensitive in females. This work expands our thinking about the ontogeny of complex vertebrate behaviors and their control by hormones and invite future studies into the developing manakin CNS.

the Society for
Integrative &