Table 2 PGLS analyses of the effects of the ambient environment including average ambient temperature, average and CV of NDVI on brain size, while controlling for various confounding effects. Variables with significant effects (P < 0.05) are highlighted in in bold. The 95% confidence intervals for the 100 trees are shown in brackets. λ is Pagel’s lambda

CV NDVI (n = 350)

Intercept

0.960 (0.959, 0.961)

0.171 (0.170, 0.173)

5.618 (5.573, 5.663)

< 0.001 (< 0.001, < 0.001)

Body mass (log-10)

0.536 (0.535, 0.536)

0.016 (0.016, 0.016)

33.284 (33.259, 33.308)

< 0.001 (< 0.001, < 0.001)

Taxon (Reptile)

0.327 (0.326, 0.328)

0.240 (0.238, 0.241)

1.365 (1.354, 1.375)

0.174 (0.171, 0.177)

Activity period (nocturnal)

-0.055 (-0.056, -0.055)

0.026 (0.026, 0.026)

-2.124 (-2.140, -2.107)

0.035 (0.034, 0.037)

Average ambient temperature

-0.002 (-0.002, -0.002)

0.003 (0.003, 0.003)

-0.915 (-0.928, -0.901)

0.362 (0.355, 0.369)

Average NDVI per year

0.067 (0.066, 0.067)

0.069 (0.069, 0.070)

0.962 (0.952, 0.972)

0.338 (0.332, 0.343)

CV NDVI per year

-0.002 (-0.002, -0.002)

0.001 (0.001, 0.001)

-1.057 (-1.068, -1.046)

0.292 (0.287, 0.297)

λ = 0.757 (0.753, 0.761); R² = 0.770 (0.770, 0.770)