Table 1.

Multiple least-squares regressions of r_max in mammals and birds (ln r_max as dependent variable, ln brain mass and ln body mass as independent variables, Homo excluded), for both species-level data (raw) or IC. (Significant effects are shown in italics.)

				brain mass		body mass
	method	n	r2	p-value	slope	p-value	slope
mammals
all species	raw	536	0.596	<0.0001	−0.955	<0.0001	+0.389
	IC	535	0.130	<0.0001	−0.428	0.353	+0.054
altricials	raw	249	0.597	0.005	−0.385	0.439	−0.079
	IC	248	0.116	0.032	−0.357	0.951	−0.006
precocials	raw	256	0.618	<0.0001	−1.157	<0.0001	+0.534
	IC	255	0.162	<0.0001	−0.519	0.068	+0.115
terrestrial Carnivora	raw	98	0.481	0.191	−0.267	0.385	−0.116
	IC	97	0.256	0.0006	−0.649	0.183	+0.154
non-canid Carnivora	raw	79	0.673	<0.0001	−0.893	0.039	+0.264
	IC	78	0.360	<0.0001	−0.976	0.014	+0.325
birds
all species	raw	388	0.352	<0.0001	−0.433	0.398	+0.042
	IC	387	0.132	0.294	−0.082	0.0007	−0.167
altricials	raw	137	0.532	0.264	+0.115	<0.0001	−0.306
	IC	136	0.123	0.216	−0.168	0.742	−0.032
semi-altricials	raw	77	0.670	0.649	−0.070	<0.0001	+0.362
	IC	76	0.332	0.586	+0.085	<0.0001	−0.443
semi-precocials	raw	42	0.326	0.0002	−1.986	0.0005	+1.201
	IC	41	0.315	0.0007	−1.772	0.002	+1.074
precocials	raw	132	0.259	<0.0001	−0.854	0.0004	+0.368
	IC	131	0.161	0.0002	−0.561	0.158	+0.115