Meeting Abstract

1-2  Thursday, Jan. 4 08:15 - 08:30  Pairing status and female breeding status influence androgen levels and ornament expression in male Red-backed Fairy-wrens WELKLIN, JF*; LANTZ, SM; KAHLIL, S; BOERSMA, JP; SCHWABL, HG; KARUBIAN, J; WEBSTER, MS; Cornell University; Tulane University; Tulane University; Washington State University; Washington State University; Tulane University; Cornell University jfw96@cornell.edu http://www.josephwelklin.com

The role of androgens in regulating behavior and the development of sexual signals has been well-established. However, most research on this topic has focused on explaining how variation in androgen levels during the breeding season matches an organism to its environment. Little is known about what causes variation in androgen levels during the non-breeding season, and the role of androgens in sexual signal expression during this period. Red-backed Fairy-wrens (Malurus melanocephalus) live in complex non-breeding social groups, and young males implanted with testosterone during the non-breeding season molt into the sexually-selected red-black plumage. Combined, the complex social environment and the sensitivity to androgens offer an ideal system for measuring how non-breeding social interactions influence androgen levels leading to differential expression or suppression of a sexually selected plumage signal. Here we present results from a series of experiments beginning in the non-breeding season and extending into breeding, showing that date of pair formation prior to the breeding season and female nesting status during breeding jointly influence expression of the sexually selected red-black plumage in males and that this is likely mediated by androgens. Combined, these results show the importance of understanding the connection between an organism’s environment and androgens across both non-breeding and breeding seasons.