Table 1. Choice of each subject bird tested in the Y-maze.

Status	sex of subject bird (n)	choice F	choice M	no choice	p value*	♀+♂-p value**
(a) breeder, sex known at time of experiment	F (11)	3	6	2	0.25	0.31
	M (9)	4	4	1	0.64
(b) breeder, sexed subsequent to experiment	F (10)	5	5	0	0.62	0.24
	M (10)	2	6	2	0.14
(c) non-breeder, sexed subsequent to experiment	F (6)	4	2	0	0.35	0.27
	M (8)	2	3	3	0.5
(a) & (b)	F (21)	8	11	2	0.32	0.5
	M (19)	6	10	3	0.23
(a) & (b) & (c)	F (27)	12	13	2	0.5	0.33
	M (27)	8	13	6	0.19

^* P values of binomial tests performed for different categories of birds are calculated ignoring birds not making a choice.

^** P values are calculated on the basis of number preferring own sex versus number preferring opposite sex.