Figure 2.

Difference in mean weight (grams) at fledging between nestling collared and pied flycatchers being raised in the same nests in relation to timing of breeding. Open squares represent nests attended by adult collared flycatchers (n=44) and filled squares represent nests attended by pied flycatchers (n=44). Mean breeding dates are indicated by open and closed arrows for collared and pied flycatchers, respectively. Nestling collared flycatchers experience an advantage when reared early in the season and when reared by pied flycatchers.