Table 1.

Results of linear models predicting average urinary testosterone and creatinine levels in 34 wild male chimpanzees

	β	SE	95% CI	t	P
Testosterone (R²_adj = 0.28)
Intercept	−0.002	0.144	[−0.295, 0.291]
Dominance rank	0.623	0.215	[0.183, 1.06]	2.89	0.007
Aggression rate	−0.437	0.194	[−0.833, −0.041]	−2.26	0.032
Age	−0.725	0.184	[−1.10, −0.349]	−3.93	<0.001
Creatinine, outlier included (R²_adj = 0.09)
Intercept	0.055	0.147	[−0.244, 0.355]
Dominance rank	0.459	0.220	[0.010, 0.908]	2.09	0.045
Aggression rate	−0.093	0.198	[−0.498, 0.311]	−0.472	0.640
Age	−0.332	0.188	[−0.716, 0.053]	−1.76	0.088
Creatinine, outlier excluded (R²_adj = 0.17)
Intercept	0.100	0.133	[−0.172, 0.372]
Dominance rank	0.434	0.198	[0.028, 0.840]	2.19	0.037
Aggression rate	0.009	0.182	[−0.363, 0.382]	0.051	0.959
Age	−0.336	0.170	[−0.683, 0.011]	−1.98	0.057

We analysed creatinine with and without an extreme outlier; the results of both models are presented. The 95% confidence intervals (CIs) were generated using the profile likelihood. Values in bold and italic fonts represent P values <0.05 and <0.10, respectively.