Tuesday, August 4, 2009 - 11:10 AM

OOS 10-10: A behavioral approach to mapping connectivity for rare butterflies on military installations

Daniel C. Kuefler1, Brian Hudgens2, Nick M. Haddad3, William F. Morris4, and Nicole Thurgate3. (1) University of Guelph, (2) Institute for Wildlife Studies, (3) North Carolina State University, (4) Duke University


Determining connectivity within landscapes composed of differentially suitable habitats is challenging. This is especially so if habitat that best facilitates dispersal differs from habitats where animals are normally found. We addressed the question of how landscape features affect dispersal by quantifying two critical aspects of animal movement behavior that determine the rate of dispersal across complex landscapes: habitat-specific displacement rates and behavior at boundaries between habitat types. Our experiments on regionally rare, wetland butterflies, including Satyroides appalachia, Neonympha areolata, and the federally endangered Neonympha mitchellii francisci, encompassed five major habitat types across Fort Bragg, NC.


Of all species observed, N. m. francisci showed the highest edge sensitivity and was least likely to exit a habitat patch. Our primary experimental species, S. appalachia, exhibited varied step lengths and turn angles among habitats, with longest and straightest paths leading to greater displacement rate in open habitat and shortest and most sinuous paths and correspondingly slowest displacement rate in riparian habitat. There was a strong negative relationship between the probability of entering a habitat and the speed of moving through it. Recognizing this central conflict between entering and moving through habitat is important for assessing the connectivity of complex landscapes.