Table 6.

Comparisons of responsiveness of current breeders with dependent and independent infants and noncurrent breeders (no infants) across the vocal tests

Test	Dependent vs independent infants						Dependent infants vs no infants			Independent infants vs no infants
	UV			OV			UV			UV*
	T	P	Cohen's d	T	P	Cohen's d	U	P	Cohen's d	U	P	Cohen's d
Latency to orient to stimulus	0.0	0.002	−0.624	0.0	0.002	−0.905	23.5	0.003	−0.633	47	0.15	−0.077
Latency to explore stimulus	0.0	0.007	−1.500	0.0	0.027	−0.400	18	0.001	−2.12	--	--	--
Latency to enter stimulus nestbox	0.0	0.027	−0.880	0.0	0.027	−0.880	36	0.038	−1.245	--	--	--
Frequency of investigatory behaviour	0.0	0.001	1.352	0.0	0.001	1.998	38	0.051	0.900	39	0.059	1.16
Time spent near stimulus	0.0	0.003	1.381	3.0	0.012	0.863	12.5	0.001	1.953	57	0.409	0.590

Stimuli were own infant vocalization (OV) and unfamiliar infant vocalization (UV). Wilcoxon signed-ranks tests were used to test between different conditions in the same parents (T) and Mann–Whitney U tests were used to compare responses between different parents (U). Effect size measure Cohen's d for two comparison of two means is reported. Significant P values are shown in bold. Also see Figs 3, 4.

^*When the behaviour did not occur in any of the compared breeding conditions the statistical comparison was not performed.