Fig 1. Relationship between longevity and eye ring (A) or bill (B) redness in male partridges with different hormonal treatments.

Redness was measured before the first breeding opportunity. Slopes were obtained from ordinary least squares linear regressions. However, Cox regression slopes should be considered (see Results and Tables 1 and 2). Control (C), flutamide (F), flutamide plus ATD (FA) and testosterone (T) treatments. Censored data were excluded here.