Abstract
A central question in landscape ecology is how organisms move through fragmented landscapes. To explore this I have studied how butterflies behave at habitat borders and how readily they move through matrix (non habitat) vegetation. My work focuses on a guild of fruit feeding nymphalid butterflies and how they react to fragmentation in a post agricultural landscape, with emphasis on the behavior and distribution of the Hackberry Emperor Asterocampa celtis and the Question Mark Polygonia interrogationis. Using a combination of observations at habitat edges and large scale trapping across different vegetation types, I measured nymphalid vegetation preference and how this preference scaled up to landscape level butterfly distribution. I found that butterflies exhibit vegetation bias at a variety of spatial scales and that movements at vegetation borders are indicative of larger scale butterfly distribution. Using mark release recapture studies, I was able to determine that vegetation preference corresponds with the conductance of different matrix vegetation types. I also conducted controlled screen house experiments to isolate the environmental cues that are important for butterfly movement. An analysis of these cues indicated that vegetation structural complexity is likely the most important driver of butterfly vegetation preference. Determining how butterflies identify different vegetation types, how readily they cross habitat edges and how easily they move through non habitat vegetation, has provided valuable insights into how butterflies react to fragmented landscapes.
