AUTHORS: Wendy Dorman, University of Illinios Urbana Champaign Michael P. Ward, University of Illinios Urbana Champaign Kirk Stodola, Illinois Natural History Survey
ABSTRACT: While many studies state that they expect birds in North America to shift their ranges north, little attention has been paid to which species will move and the mechanism by which ranges shift. Extralimital occurrences involve individuals occurring outside of their species’ core breeding distribution. The probability of extralimital occurrences may be used to infer the potential of a species to expand their range, while the location of extralimital occurrences could indicate potential areas where the range may expand. Combining eBird data, spatial modeling, and pattern analysis, I investigated range plasticity via extralimital occurrences of migrants north of their breeding distributions in the Midwest. Using dynamic occupancy modeling we predicted the likelihood of a given species to expand its range into particular areas and examined the relationship between predicted colonization and realized range shifts. We will discuss the potential for these metrics to be incorporated into an index of range plasticity.
