Table 3. Phylogenetic generalised least-squares (PGLS) regression analyses examining the effects of social, ecological and life-history variables* on carnivoran whole and regional brain volumes.
Preferred models represent the ‘best fit’ model (with the lowest BIC score) of the overall model category (i.e., social or ecological). The combined models represent the ‘best fit’ model after running all combinations of the previous ‘best fit’ models (models one to four). Boldness indicates the model(s) with the lowest BIC score across all models (dBIC<2).
| Brain input | Overall model | Preferred model | BIC score | P-value | λ | Adj. r2 | Sample size (n) |
|---|---|---|---|---|---|---|---|
| Endocranial volume | Social | ECV ~ Mass + GS | -137.3671 | <0.001 | 0.784 | 0.911 | 85 |
| Ecological | ECV ~ Mass + HV | -138.8228 | <0.001 | 0.810 | 0.9102 | 85 | |
| Social & Ecological | ECV ~ Mass + GS + HV | -135.0748 | <0.001 | 0.814 | 0.9095 | 85 | |
| Life History | ECV ~ Mass + F | -140.9778 | <0.001 | 0.762 | 0.9166 | 85 | |
| Combined | ECV ~ Mass + DB + F | -140.4778 | <0.001 | 0.753 | 0.9201 | 85 | |
| All | ECV ~ Mass + GS + SC + D + DB + HV + HR + GL + ML + F + FR + WA | -106.9128 | <0.001 | 0.724 | 0.9221 | 85 | |
| Neocortex (ROB) | Social | Neo ~ GS | 71.58854 | 0.06425 | 0.954 | 0.05726 | 44 |
| Ecological | Neo ~ HR | 68.10774 | <0.01 | 0.334 | 0.196 | 44 | |
| Social & Ecological | Neo ~ GS + HR | 70.20444 | <0.01 | 0.400 | 0.1938 | 44 | |
| Life History | Neo ~ FR | 58.64386 | <0.001 | 0.097 | 0.414 | 44 | |
| Combined | Neo ~ HR + FR | 59.78632 | <0.001 | 0 | 0.48 | 44 | |
| All | Neo ~ GS + SC + D + DB + HV + HR + GL + ML + F + FR + WA | 87.42208 | <0.001 | 0 | 0.4546 | 44 | |
| Cerebellum (ROB) | Social | Cere ~ GS | 35.60386 | 0.07056 | 1 | 0.06265 | 38 |
| Ecological | Cere ~ HR | 20.3267 | <0.001 | 1 | 0.3729 | 38 | |
| Social & Ecological | Cere ~ GS + HR | 22.22221 | <0.001 | 1 | 0.3839 | 38 | |
| Life History | Cere ~ GL + ML + FR | 4.668459 | <0.001 | 1 | 0.6369 | 38 | |
| Combined | Cere ~ HR + GL + ML + FR | 3.803654 | <0.001 | 1 | 0.6677 | 38 | |
| All | Cere ~ GS + SC + D + DB + HV + HR + GL + ML + F + FR + WA | 28.10051 | <0.001 | 1 | 0.6135 | 38 |
*GS = Group size, SC = Social cohesion, D = Diet, DB = Dietary breadth, HV = Habitat variability, HR = Home range, GL = Gestation length, ML = Maximum longevity, F = Fertility, FR = Age at first reproduction, WA = Weaning age.