Table 2.

Summary data for log₁₀/log₁₀ linear regressions of surface area (SA) parameters against body size estimates and chamber volume. ‘Group’ indicates whether the entire sample was used (all) or one of the habitat groups; A, aquatic, T, terrestrial. For species assignments, see Table 1. All regressions were significant at the 0.05 level. A * indicates that the y-intercepts for the aquatic and terrestrial species were significantly different at the 0.05 level

Linear regression	n	Group	Slope (b)	y-intercept	r2	95% CI for slope
Against body mass
Total surface area	30	All	0.61	3.61	0.93	0.55–0.68
Respiratory SA	30	All	0.75	3.03	0.93	0.67–0.83
Olfactory SA	30	All	0.47	3.48	0.72	0.36–0.58
	9	A	0.49	3.13*	0.45	0.08–0.91
	16	T	0.6	3.5*	0.94	0.52–0.69
Against skull length
Total surface area	28	All	1.96	0.06	0.94	1.75–2.16
Respiratory SA	28	All	2.38	−1.27	0.90	2.07–2.68
Olfactory SA	28	All	1.56	0.61	0.80	1.25–1.87
	9	A	1.77	−0.14	0.72	0.87–2.68
	16	T	1.77	0.31	0.93	1.48–2.05
Against chamber volume
Total surface area	30	All	0.71	1.213	0.95	0.65–0.77
	9	A	0.86	0.48	0.75	0.41–1.31
	16	T	0.67	1.34	0.97	0.61–0.73
Respiratory SA	9	A	0.86	0.33	0.56	0.18–1.54
	16	T	0.79	0.3	0.99	0.74–0.84
Olfactory SA	9	A	0.82	0.03	0.83	0.49–1.15
	16	T	0.61	1.44	0.95	0.53–0.69