Top log-linear Poisson models predicting the counts of bird clusters observed along transects.

All terms used, except the intercept (int.), were categorical (0 = low, 1 = high) and include summer weather (T), lemming abundance (L), terrain ruggedness (R), amount of freshwater (W), and vegetation productivity (N). Only models with ΔAICc values aBootstrap standard errors*Coefficient estimate significantly different from 0 (α = 0.05) based on bootstrap percentile confidence intervals.**Coefficient estimate significantly different from 0 (α = 0.01) based on bootstrap percentile confidence intervals.