Fields in Data Sets Year year data were gathered NestID nest identification number social individual bird identification number EPP extra-pair paternity detected (yes/no) condition body condition index mass body mass (g) tarsus tarsus length (mm) wing wing chord (mm) Kipp Kipp's distance notch depth of primary notch (mm) tail tail length (mm) asym tail asymmetry; i.e., difference between left and right rectrices (mm) functional functional tail feather length (mm) ornament ornamental tail feather length (mm) FlankL flank darkness (L* on Hunter scale) FlankA flank redness (a* on Hunter scale) FlankB flank yellowness (b* on Hunter scale) WingL axillary darkness WingA axillary redness WingB axillary yellowness sex male or female class long-tailed male; short-tailed male; female navigate success or failure to navigate flight tube (1/0) collide collision within flight tube (1/0) hits number of collisions Modifiers: leading s- social male leading c- cuckolder