Date of this Version
Witmer, G.W. and A.B. Shiels. 2018. Ecology, impacts, and management of invasive rodents in the United States. pgs. 193-219. In: W.C. Pitt, J.C. Beasley, and G.W Witmer, editors. Ecology and Management of terrestrial vertebrate invasive species in the United States. CRC Press, Boca Raton, FL. 403 pp.
Approximately 42% of all mammalian species in the world are rodents, amounting to about 2277 species (Wilson and Reeder 2005). Rodents have adapted to all lifestyles: terrestrial, aquatic, arboreal, and fossorial (underground). Most species are small, secretive, nocturnal, adaptable, and have keen senses of touch, taste, and smell. For most species of rodents, the incisors continually grow throughout their life span, requiring constant gnawing to keep the incisors sharp and at an appropriate length. This can result in extensive damage to seeds, fruits, field crops, structures, wires, and insulation. Rodents are known for their high reproductive potential; however, there is much variability between species as to the age at first reproduction, size of litters, and the number of litters per year. All these characteristics make many rodent species ideal invaders.
Rodents have ecological, scientific, social, and economic values (Witmer et al. 1995; Dickman 1999). Rodents are important in seed and spore dispersal, pollination, seed predation, energy and nutrient cycling, the modification of plant succession and species composition, and as a food source for many predators. Additionally, some species provide food and fur for human uses. Hence, the indiscriminate removal of native rodents from ecosystems, including agroecosystems, is not the best management option in many cases (Villa-Cornejo et al. 1998; Aplin and Singleton 2003; Brakes and Smith 2005).