Table 1.

Summary of OLS and PGLS regression analyses for the body mass dependence of RBT, RSA, and oxygen consumption rates in endothermic (birds and mammals) and ectothermic (fishes, amphibians, and reptiles) vertebrates

Models	N	df	I	95% CI	P	M	95% CI	P	R2
RBT, μm
Endotherms
PGLS (Fig. 1B)	56	54	0.13	(0.09,0.21)	**	0.1	(0.06,0.14)	**	0.32
OLS	59	57	0.13	(0.1, 0.17)	**	0.11	(0.08,0.15)	**	0.43
Ectotherms
PGLS (Fig. 1B)	33	31	1.85	(1.05,3.25)	0.04	−0.04	(-0.11,0.03)	0.27	0.03
PGLS-NoA	18	16	2.97	(1.15,7.69)	0.04	−0.11	(-0.23,0.01)	0.1	0.12
OLS	44	42	1.91	(1.27, 2.91)	**	−0.04	(-0.12,0.04)	0.08	0.02
RSA, cm2
Endotherms
PGLS(Fig. 1A)	48	46	58.55	(31.5,109.9)	**	0.89	(0.83,0.95)	**	0.98
OLS	51	49	57.97	(45.6,74.44)	**	0.9	(0.86,0.93)	**	0.98
Ectotherms
PGLS(Fig. 1A)	24	22	6.88	(2.69,17.63)	**	0.78	(0.65,0.9)	**	0.81
PGLS-NoA	12	10	3.53	(0.81,13.59)	0.12	0.85	(0.64,1.06)	**	0.91
OLS	33	31	8.93	(5.15,15.33)	**	0.76	(0.64,0.87)	**	0.85
O2 consumption, mL O2/h
Endotherms
PGLS (Fig. 2A)	580	578	3.28	(1.95,5.58)	**	0.75	(0.73,0.78)	**	0.95
OLS	580	578	4.09	(3.78,4.39)	**	0.7	(0.69,0.71)	**	0.95
Ectotherms
PGLS (Fig. 2B)	249	247	0.13	(0.02,0.63)	**	0.84	(0.8,0.89)	**	0.80
OLS	249	247	0.10	(0.08,0.13)	**	0.9	(0.85,0.95)	**	0.82
O2 diffusion
Endotherms			4.78	(3.71,5.55)		0.79	(0.77,0.81)
Ectotherms			0.15	(0.1,0.21)		0.82	(0.76,0.87)

The character “I” represents the intercept of the scaling relationship and “M” represents the scaling exponent. P values of P < 0.001 are noted with asterisks. Statistics listed as “NoA” represent those without amphibians (Methods). Data and sources are listed in SI Appendix, Appendixes 1 and 3.