Fit and fat from enlarged badges: a field experiment on male sand lizards.

To investigate the impact of nuptial coloration (the badge) on male fitness in the Swedish sand lizard (Lacerta agilis), we conducted a manipulation experiment in a natural population. Males in one group had their badges enlarged by being painted as cheaters and were compared to a control group with respect to mate acquisition, body condition and survival. Badge enlargement did not affect survival, but elevated mate acquisition by almost 400%, and body condition in small males. This increase in condition is likely to stem from greater access to female-associated sites with high food availability.