Table 1.

Number of males and females (M/F) in the CONT (n = 52) or SUPPL (n = 45) clutches included in the study where c-eggs could be sexed. χ² tests of the difference in frequency of males and females in the two groups for all laying order positions are presented. The number of sexed offspring for a- and b-eggs does not sum up to the total number of clutches in either group because of disappearance of the eggs, egg infertility, and hatchling mortality (see also §2). All within treatment-by-laying order Binomial tests for deviation from a 1 : 1 sex ratio were not significant after Bonferroni correction for n = 6 tests.

	control	food supplemented		p
a-eggs	17/22	21/17	1.05	0.306
b-eggs	31/15	19/17	1.81	0.178
c-eggs	34/18	27/18	0.30	0.584