Table 3. Results of linear regression model fits of ecological variables that covary significantly with cranial shape, against other ecological variables.

df, degrees of freedom; Adj. SS, adjusted sum of squares; Adj. MS, adjusted mean square; F, F statistic; P, significance level.

	df	Adj. SS	Adj. MS	F	P	Direction of change
CS
Regression	13	2,484,639	191,126	3.62	0.004*	—
Mean monthly temperature	1	127,563	127,563	2.42	0.135	—
Sexual maturity age	1	709,585	709,585	13.45	0.001*	Later
Maximum longevity	1	46,664	46,664	0.88	0.358	—
Mean monthly precipitation	1	34,244	34,244	0.65	0.429	—
Activity cycle	2	62,308	31,154	0.59	0.563	—
Terrestriality/ arboreality	1	30,672	30,672	0.58	0.454	—
Habitat breadth	2	41,330	20,665	0.39	0.681	—
Diet breadth	4	196,926	49,231	0.93	0.464	—
Error	21	1,107,578	52,742
Total	34	3,592,217
Sexual maturity age
Regression	12	4,301,175	358,431	4.14	0.002*	—
Mean monthly temperature	1	16,199	161,99	0.19	0.669	—
Maximum longevity	1	1,488,525	1,488,525	17.21	<0.001*	Longer
Mean monthly precipitation	1	11,434	11,434	0.13	0.72	—
Activity cycle	2	262,025	131,012	1.51	0.242	—
Terrestriality/ arboreality	1	26,785	26,785	0.31	0.584	—
Habitat breadth	2	268,973	134,487	1.55	0.234	—
Diet breadth	4	1,518,075	379,519	4.39	0.009*	Pandas
Error	22	1,902,972	86,499
Total	34	6,204,148
Precipitation
Regression	12	42,736.3	3,561.36	3.74	0.004*	—
Mean monthly temperature	1	8,341	8,341	8.77	0.007*	Higher
Sexual maturity age	1	125.8	125.77	0.13	0.72	—
Maximum longevity	1	47.6	47.59	0.05	0.825	—
Activity cycle	2	520.3	260.13	0.27	0.763	—
Terrestriality/ arboreality	1	5,226.9	5,226.94	5.49	0.029*	Aboveground
Habitat breadth	2	157.1	78.54	0.08	0.921	—
Diet breadth	4	6,525.3	1,631.33	1.71	0.183	—
Error	22	20,933.4	951.52
Total	34	63,669.7

*Statistical significance at the P = 0.05 level.