USDA National Wildlife Research Center Symposia


Date of this Version



Published in: Witmer, G. W., W. C. Pitt, and K. A. Fagerstone, editors. 2007. Managing vertebrate invasive species: proceedings of an international symposium. USDA/APHIS Wildlife Services, National Wildlife Research Center, Fort Collins, Colorado, USA. Also available online at


At least 161 introduced/invasive vertebrates have become established in the United States and its territories, including at least 81 mammalian, 94 avian, and 86 reptilian/amphibian species. Particularly problematic species include feral cats and dogs; feral pigs; commensal rats and mice; starlings, pigeons, and house sparrows; and bullfrogs, brown treesnakes, and coqui frogs. We briefly review these introductions and the types of damage they cause. We review the basic types of methods used for control or eradication of each taxonomic group, including physical, chemical, biological, and cultural methods. We also discuss some of the challenges in managing these species, including issues with the use of toxicants, land access, public attitudes, and monitoring difficulties. Finally, we discuss some ongoing research and future research needs, including fertility control, improved detection methods, improved attractants, improved barriers, improved capture methods, and risk assessment methods.