Figure 2.

Effect of the decreasing condition of the female parent (manipulated by continuous egg removal) on the survival of male (solid line) and female offspring (dashed line). (a) When parents were given no food supplements during the prelaying period, the survival rate of male chicks declined significantly with position in the laying sequence (logit(survival) = 2.186 − 0.342 (± 0.178) × sequence), whereas that for females remained constant (mean value shown). (b) When parents were given a prelaying food supplement, survival rates were unaffected by position in the laying sequence in either sex; overall survival rates are shown. See text and Table 1 for all analyses.