Meeting Abstract

107.5  Tuesday, Jan. 7 09:00  A possible trade-off between song and a cognitive metric in song sparrows SEWALL, KB*; SOHA, JA; PETERS, S; NOWICKI, S; Virginia Tech; Duke University ksewall@vt.edu

Sexual ornaments can be honest signals of male quality if they are linked to traits that enhance female reproductive success. Males might be expected to invest maximally in traits important to females and thus in sexual ornaments. However, mechanisms that link sexual ornaments with other character traits also may be the basis for trade-offs between traits. Bird song is a sexual ornament that depends principally upon brain structure and function, making it reflective of at least some measures of neural capacity and cognition. We explored the possibility that constraints on brain growth could lead to a trade-off between song and cognition in song sparrows (Melospiza melodia). Specifically, we examined the relationship between song repertoire size and performance on a spatial task. We found an inverse relationship between repertoire size and speed of spatial learning and suggest that a developmental trade-off between the hippocampus and song control nuclei could be responsible for this relationship. Differences in how males resolve this trade-off between brain-dependent traits could contribute to the spectrum of variation in song and cognition. Such a trade-off suggests that song can inform females about a suite of male traits rather than a single metric of condition.