Forest Habitat Reduces the Flight ofPontia occidentalis(Reakirt) (Lepidoptera: Pieridae) Relative to Alpine Meadow Habitat

Abstract

ABSTRACT. We compared the movement of Pontia occidentalis in forest and meadow habitat. We hypothesized that flight distances and overall movement would be greater in forested habitat than in meadow habitat. This hypothesis was based on forging theory predicting that organisms should spend less time in areas where resources are scarce than where they are abundant. Because this species is a generalist in its use of open habitat and regularly encounters forest when dispersing and hilltopping, we also hypothesized that forested habitat would not impose a physiological limitation on their flight. To test this hypothesis we released 68 butterflies in either forest or alpine meadow habitat and followed their movement. Contrary to our hypothesis, the total distance moved, mean flight distance, and rate of flight were all lower in forest relative to meadow habitat. Forest habitat did not exert an edge effect for Pontia occidentalis flying in meadow habitat. Contrary to our second hypothesis, differences in moveme...