Table 2.
Bowhead whale SSF model selection table for all single-variable models (italicized models) paired with a model for that variable that also includes the interaction of that variable with distance to killer whales (bolded models)
| Model | d.f. | AICc | ∆AIC | L.Ratio | p |
| use ∼ Dsh | 1 | 21,081 | 154 | — | — |
| use ∼ Dsh + Dsh:Dkw | 2 | 20,927 | 0 | 156.1 | <0.0001 |
| use ∼ Depth | 1 | 21,239 | 312 | — | — |
| use ∼ Depth + Depth:Dkw | 2 | 21,133 | 206 | 108.5 | <0.0001 |
| use ∼ Dedge*isice | 2 | 21,366 | 439 | — | — |
| use ∼ Dedge:isice + Dedge:isice:Dkw | 3 | 21,139 | 219 | 232.8 | <0.0001 |
| use ∼ SIconc + SI2conc | 2 | 21,272 | 345 | — | — |
| use ∼ SIconc + SI2conc + SIconc:Dkw + SI2conc:Dkw | 4 | 21,173 | 246 | 102.0 | <0.0001 |
| use ∼ SIconc | 1 | 21,323 | 396 | — | — |
| use ∼ SIconc + SIconc:Dkw | 2 | 21,237 | 314 | 84.0 | <0.0001 |
| use ∼ null | 1 | 21,337 | 410 | — | — |
| use ∼ Dkw | 1 | 21,348 | 421 | — | — |
In every case, adding interaction with distance to killer whales improves model fit substantially. In all cases, likelihood ratio tests indicate improvement in fit is highly significant. Also note that distance to killer whale as a single main effect fits worse than the null model. Interaction models that also include the main effect of Dkw are not shown, as they do not improve fit. See Table 1 for definition of terms. d.f., model degrees of freedom.