bioRxiv preprint doi: https://doi.org/10.1101/453548; this version posted June 17, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 The authors wish to be identified to the reviewers. 2 Testosterone modulates status-specific patterns of cooperation in a 4 social network 6 Short title: Testosterone modulates cooperation 8 T. Brandt Ryder1*§, Roslyn Dakin1§, Ben J. Vernasco2, Brian S. Evans1, Brent M. Horton3, and Ignacio T. Moore2 10 1Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, 12 Washington, DC 20013, USA 2Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061, USA 14 3Department of Biology, Millersville University, Millersville, Pennsylvania 17551, USA 16 §Authors contributed equally 18 *Correspondence:
[email protected] bioRxiv preprint doi: https://doi.org/10.1101/453548; this version posted June 17, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 2 20 Summary Stable cooperation requires plasticity whereby individuals are able to express competitive or 22 cooperative behaviors depending on social context. To date, however, the physiological mechanisms that underlie behavioral variation in cooperative systems are poorly understood. We 24 studied hormone-mediated behavior in the wire-tailed manakin (Pipra filicauda), a gregarious songbird whose cooperative partnerships are crucial for fitness.