Table 1. Factors that influenced whether females grunted after they approach another female.

	Odds Ratio	S.E.	Z	P
Infant presence	14.47	0.60	63.94	< 0.001
Relative rank	1.41	0.08	6.45	<0.001
Kinship
Cousins	1.07	0.24	0.28	0.777
Aunts & nieces	0.94	0.12	-0.51	0.608
Sisters	0.96	0.14	-0.29	0.770
Mothers & daughters	0.48	0.07	-4.89	< 0.001

Results were obtained from a multi-level mixed-effects logistic regression model (n = 12,263 approaches involving 64 adult females).