Figure 2. Relationship between δ ²H_f and isoscape predicted δ ²H_p.

A) For 542 model calibration samples, B) for Neotropical migrants, C) for short-distance migrants, and D) for resident species. The relationship between δ ²H_f and δ ²H_p was modeled using a linear modeling approach with lines indicating predictions from our best AIC_c selected model (see methods). Our best model included a factor for whether the species foraged on the ground or elsewhere; thus, the predictive equations and regression line are shown separately for ground foragers (solid lines) and non-ground foragers (dashed lines).