Session Information
| Session | Poster Session | | Date | Monday (2008-04-07) | | Time | 5:00 PM - 7:00 PM | | Room | Grand Terrace |
Presentation Information
| Presenter | Norah Warchola | | Title | Butterfly movement in a post agricultural landscape | | Affiliation | Stony Brook University | | Authors | Norah Warchola | | Keywords | Asterocampa celtis, Habitat fragmentation, Lepidoptera, Matrix | | Presentation Type | Poster | Abstract:
A central question in landscape ecology is how to increase connectivity in fragmented landscapes. The utility of various methods, like corridors and stepping stones, depends on the behavior of the target organism. Further, the pieces of land required may be expensive to obtain or already developed. A better understanding of the environmental cues used to make movement decisions may allow for manipulations of matrix vegetation short of returning it to habitat. Manipulations like addition of host plants or structural alterations may be effective in increasing movement rates. These targeted efforts may be combined with traditional corridors and stepping stones to create cheaper and potentially more effective ways to increase movement in species of concern. Whenever increased connectivity is desired, one needs to consider that corridors may be used as sub optimal habitat or that individuals in the matrix may have poor survival. In these cases, increasing movement may do mare harm than good. This study focuses on how a guild of fruit feeding nymphalid butterflies react to fragmentation in a post agricultural landscape, with emphasis on the behavior and distribution of the Hackberry Emperor Asterocampa celtis. This species is found in shrubland and forest vegetation in close proximity to its host plant the Hackberry Celtis occidentalis. Butterflies are ideal organisms to answer these questions, as their behavioral decisions are less complicated than vertebrates. Further, the majority of species move distances that are amenable to landscape level studies of fragmentation. This work was conducted at the University of Virginia’s Blandy Experimental Farm. Using a variety of methods, I measured Nymphalid behavior at vegetation borders and how this scales up to landscape level butterfly distribution. I also conducted experiments where larval A. celtis were placed on host plants in matrix vegetation. Survival was monitored to measure the potential for the matrix to act as an ecological trap. Initial experiments show that butterflies exhibit vegetation bias at a variety of spatial scales and that movement at vegetation borders is indicative of larger vegetation preferences. Larval A. celtis experimentally placed in non preferred vegetation types have reduced survival, suggesting that host plants in these areas could serve as ecological traps. Further research will focus on the environmental cues that butterflies use to make movement decisions. A better understanding of these cues, combined with knowledge of potential ecological traps will allow us to determine the best ways to manipulate connectivity of landscapes. |
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