Despite the many effects that the black-tailed prairie dogs have on the terrestrial environment and on other organisms living on the prairie, how critical are black-tailed prairie dogs to the survival of other organisms? That is, are black-tailed prairie dogs keystone species? According to Paine (1969), keystone species are defined as a species whose “activities greatly modified species composition and physical appearance” and influence “the integrity of the community and its unaltered persistence.” While over 134 species of vertebrates benefit from the black-tailed prairie dog and its activities, there are a couple of species that would likely die out if the black-tailed prairie dog were to go extinct (to see a table of the associated species, click here). The black-footed ferret is so specialized on prairie dogs as a source of food that it would not likely persist if prairie dogs were eliminated (Kotliar et al., 1999). Other species associated with prairie dog colonies, such as deer mice (O’Meilia et al., 1982), Swift Foxes (Sharps, 1989), and Golden Eagles (Cully, 1991), have been observed at densities of up to three to four times greater when compared to the densities of similar populations on uncolonized grasslands.
At a terrestrial level, the black-tailed prairie dog provide a continuous and large-scale disturbance of the environment, which is necessary for both species composition and ecosystem function (Kotliar et al., 1999). Disturbances are provided by nomadic ungulates and fossorial mammals, as well as natural disturbances such as fire, but these disturbances are simply too sporadic or too small in scale.
Based on the widespread effect of beneficial disturbance that the black-tailed prairie dog has on its terrestrial environment, as well as other species’ dependence on it for survival and/or improved population numbers, it is evident that the black-tailed prairie dog is a cornerstone of ecosystem integrity and persistence. We can thus conclude that the black-tailed prairie dog is indeed a keystone species.