The research reported in this paper was supported by a grant from the National Science Foundation (DRL 0739874) and by Washington University in St. Louis. We thank those who provided critical review of an earlier version of this article and Katie Westby for statistical analysis support. We greatly appreciate the support of Kim Medley, Lydia Toth, Phyllis Balcerzak, the staff at Shaw Nature Reserve, and the Tyson Research Center field station community in the development and continuation of the SIFT and TERF programs. This research was approved by the Institutional Review Board at Washington University in St. Louis (IRB 201110063).