Table 4.

Fitness associations with absolute endocranial volume: results from the lifetime breeding success (males and females) and lifetime reproductive success (females) models for adults (3+ years of age, EV = endocranial volume, means in millilitres for EV and millimetres for jaw length, a t-statistic for female LBS and a z statistic for other models were automatically determined by R and depended on whether the standard errors were known, bold and italic = significant). (GLMs consisted of LBS or LRS as the response variable and endocranial volume and jaw length as fixed effects. The male LBS model had a negative binomial distribution and a log link; the female LBS model had a quasi-Poisson distribution with a log link because it was overdispersed; and the female LRS model had a Poisson distribution with a log link.)

		absolute endocranial volume				jaw length
model	N	estimate	s.e.	t/z	p-value	estimate	s.e.	t/z	p-value
LBS male	166	0.003	0.009	0.31	0.76	0.09	0.02	4.10	<0.001
LBS female	244	0.001	0.001	1.02	0.31	0.02	0.003	4.96	<0.001
LRS female	244	0.004	0.002	2.17	0.03	0.02	0.004	5.61	<0.001