"Prairie dogs are excellent models for a study of dispersal because they are easy to live-trap, mark, and observe," says Hoogland, "And they usually move only short distances to nearby territories."
Why are prairie dogs so different regarding dispersal? According to Hoogland, prairie dogs resemble other animals and compete with nearby kin for resources such as burrows and mates. But prairie dogs also cooperate with kin in the excavation of burrows that can be as deep as 15 feet; in defense of the home territory against prairie dogs from other territories; by giving alarm calls when a large predator such as a coyote attacks; and by helping to chase small predators such as long-tailed weasels. Another important cooperative behavior is communal nursing (the suckling of non-offspring), which can be life-saving for the unweaned offspring of close kin when the mother of those offspring dies for any reason.
Hoogland hypothesizes that the benefits of cooperation with close kin exceed the costs of competition with those same close kin. When all close kin disappear, individuals disperse because they have nobody with whom to cooperate. When the option is available, prairie dogs frequently disperse into a territory that contains close kin who dispersed there earlierso that benefits from cooperation are once again available.
Scientists at the University of Maryland Center for Environmental Science's Appalachian Laboratory in Frostburg actively study the effects of land-use change on terrestrial and freshwater ecosystems and how human activity may influence their health and sustainability on local, regional and global scales. The scientific results help to unravel the consequences of environmental change,
|Contact: Amy Pelsinsky|
University of Maryland Center for Environmental Science