Table 2.

Results of the linear mixed-effects models to show the relationships between acoustic features of giant panda bleats and log male faecal androgen metabolite concentrations. (Significant p-values are in bold.)

acoustic measures	within-subject effect				between-subject effect
	estimates ± s.e.	d.f.	F	p	estimates ± s.e.	d.f.	F	p
log duration	0.294 ± 0.137	1,16	7.62	0.01	−0.506 ± 0.258	1,4	1.56	0.28
log mean F0	0.000 ± 0.038	1,16	0.28	0.61	0.071 ± 0.138	1,4	0.45	0.54
log F0 modrate	0.029 ± 0.064	1,16	0.58	0.46	0.199 ± 0.006	1,4	12.14	0.02
F0 modextent	−0.023 ± 44.797	1,16	0.00	0.96	−33.377 ± 68.147	1,4	0.07	0.81
log jitter	0.004 ± 0.098	1,16	0.06	0.80	0.042 ± 0.095	1,4	0.26	0.64
formant spacing	−10.880 ± 9.873	1,16	0.75	0.40	4.839 ± 15.877	1,4	0.37	0.55