Figure 1.

A schematic representation of our experimental set-up. Each experimental nest consisted of two pairs of weight-matched inbred (= dark grey) and outbred (= light grey) birds, that were placed either in a size advantaged position (= dark grey beaks), or in a size disadvantaged (= light grey beaks) position. Each pair of inbred and outbred birds hatched from either early laid eggs (=first or second laid egg) or late laid eggs (= all later laid eggs). Hatching from an early laid egg matched a size advantaged position in the nest, whereas hatching from a late laid egg mismatched a size advantage, and vice versa for birds reared in size disadvantaged positions.