(A) Classification and regression tree illustrating predicted classification of birds’ departure decisions: stopover at coastal AL site for ≥24 h, over-land departure, or over-water departure. Box plots illustrate median and quartiles for variables predicting departure decision from AL: (B) fat scores, (C) humidity, and (D) 24-h change in humidity at sunset on the evening of capture. Negative values for change in humidity denote a drop in humidity, whereas positive values denote an increase in humidity. Sample sizes refer to number of individuals predicted in each class and the proportion reflects the accuracy of classification to each departure group.