Table 2.
Top models (dAICc < 7) for Peromyscus maniculatus (a) and Myodes gapperi (b) stable isotope signatures sampled in Maine and New Hampshire, USA (2014 and 2015) and sorted by AICc. External filters are landscape‐scale processes that decrease local (within‐habitat) variation and were represented by a categorical, nominal variable for habitat (N = 3 plant community types; beta values not shown). Internal filters are local‐scale processes that increase within‐habitat variation and were represented by a categorical, nominal variable for trapping site (N = 26 locations; beta values not shown). Explanatory variables were z‐standardized. Condition is body‐mass residual
| Filter | Beta (SE) | AICc | dAICc | w | ||
|---|---|---|---|---|---|---|
| (a) | δ15N | Internal | Condition × 0.12 (0.057) | 383.8 | 0 | 0.80 |
| Internal | Condition × 0.12(0.057) + δ13C × 0.007(0.065) | 386.6 | 2.8 | 0.20 | ||
| δ13C | External | – Year × 0.56(0.12) + δ15N*0.11(0.048) − Condition × 0.035 (0.005) | 290.7 | 0 | 0.37 | |
| Internal | – Condition × 0.049 (0.051) | 291.6 | 0.9 | 0.24 | ||
| External | – Year*0.59(0.13) + δ15N × 0.096(0.056) − Condition × 0.041(0.051) – Day × 0.0024(0.0030) | 292.2 | 1.6 | 0.17 | ||
| (b) | δ15N | Internal | Condition *0.042(0.059) | 568.5 | 0 | 0.54 |
| Internal | – δ13C*0.10(0.070) + Condition × 0.050(0.059) | 568.8 | 0.3 | 0.46 | ||
| δ13C | Internal | Condition × 0.84 (0.067) | 288.0 | 0 | 0.54 | |
| Internal | – δ15N × 0.13(0.089) + Condition × 0.090(0.067) | 288.3 | 0.3 | 0.46 |