Gunnison's Prairie Dog (Cynomys gunnisoni)
Status of species: Rare
Distribution: The ďFour CornersĒ area, namely southeastern Utah, southern Colorado, northern New Mexico and northeastern Arizona
General Description: Gunnisonís prairie dogs are social hibernating ground squirrels that live in the montane valleys and high grass prairies of the Four Corners area. Probably the species from which all other prairie dogs diverged, Gunnisonís prairie dogs share some behaviors with their ďpure ground squirrelĒ ancestors in spite of being prairie dogs. Consequently, they are the most unique and least specialized prairie dog species. Gunnisonís are the only prairie dog species with 40 chromosomes (all others have 50), and aggregations of Gunnisonís are not particularly dense or large, despite their social behavior and structure being similar to other prairie dogs. Study of their complicated antipredator system has helped scientists gain incredible information about animal learning and communication.
Recreational shooting has contributed to the demise of prairie dogs in the American West. Purchasing guns for the expressed purpose of ďsportĒ hunting is commonplace, and many states have no laws that limit the amount of ďtakeĒ with respect to prairie dogs.
Photo by Theodore G. Manno.
Behavior: The breeding cycle of Gunnisonís is similar to other species of prairie dog. Females and males can mate at one year of age, although three-fourths of males defer breeding until their second year. Multiple breeding is fairly common. Litters are born from early April to late May and range from one to seven young. Females nurse young until one or two weeks after their emergence from the nursery burrow, and occasionally move to another part of the colony thereafter. Most females stay in the same clan for life. Gunnisonís prairie dogs hibernate during the winter, and become torpid much later in the fall than white-tailed or Utah prairie dogs.
The amount of social behavior varies by colony, but individuals typically live in clans with an adult male, females, and their young. Unlike other prairie dogs, home ranges overlap, and clan boundaries are not distinct. Territorial defense sometimes occurs between members of different clans, and amicable interactions like kissing and sniffing occur among clan members. In contrast to other prairie dog species, Gunnisonís prairie dogs do not commit infanticide.
Although not commonly seen in zoos, Gunnisonís prairie dogs became known to non-scientists after the discovery that their alarm calls contain semantic information about the color and shape of colony intruders that only other prairie dogs can hear. Perhaps the most highly developed antipredator communication system known among animals, Gunnisonís are usually forewarned of predators by kin and can escape to their burrows. Perhaps other species of prairie dog have these extraordinary sound communication abilities as well.
Ecological Information: Gunnisonís prairie dogs are an important food source for other animals in the Four Corners. Unlike other prairie dogs, Gunnisonís do not cut down tall vegetation to obtain an unobstructed view of possible predators. They are apparently very susceptible to introduced bubonic plague, probably more than other prairie dog species, and the reasons for this are unknown.
Management Information: Populations of Gunnisonís prairie dogs are fragmented, because campaigns have been waged against the species in the name of protecting agriculture. Lack of knowledge and efforts to manage plague have also contributed to significant mortality.
Federal agencies have refused to consider the petitions that have been filed to grant listing. Petrified Forest National Park houses and protects a Gunnisonís prairie dog colony. The species has basically no protection beyond this, despite its rarity.
- Cully, J.F. 1991. Response of raptors to reduction of a Gunnisonís prairie dog population by plague. American Midland Naturalist 125:140-149.
- Fitzgerald, J.P., and R.R. Lechleitner. 1974. Observations on biology of Gunnisonís prairie dog in central Colorado. American Midland Naturalist 92:146-163.
- Graves, R.A. 2001. The prairie dog: Sentinel of the Plains. Texas Tech University Press, Lubbock.
- Haynie, M.L., R.A. Van den Bussche, and J.L. Hoogland. 2003. Parentage, multiple paternity, and breeding success in Gunnisonís and Utah prairie dogs. Journal of Mammalogy 84:1244-1253.
- Hoogland, J.L. 1998. Why do female Gunnisonís prairie dogs copulate with more than one male? Animal Behavior 55:351-359.
- Hoogland, J.L. 2001. Black-tailed, Gunnisonís, and Utah prairie dogs all reproduce slowly. Journal of Mammalogy 82:917-927.
- Lechleitner, R.R., L. Kartman, M.I. Goldenberg, and B.W. Hudson. 1968. An epizootic of plague in Gunnisonís prairie dogs (Cynomys gunnisoni) in south-central Colorado.
- Paseka, A.D., and C.N. Slobodchikoff. 2004. Discrimination of color by Gunnisonís prairie dogs in alarm calls. Integrative and Comparative Biology 44:735-735.
- Placer, J., and C.N. Slobodchikoff. 2004. A method for identifying sounds used in the classification of alarm calls. Behavioural Processes 67:87-98.
- Raynor, L.S., A.K. Brody, and C. Gilbert. 1987. Hibernation in the Gunnisonís prairie dog. Journal of Mammalogy 68:147-150.
- Raynor, L.S. 1988. Social organization and space-use in Gunnisonís prairie dog. Behavioral Ecology and Sociobiology 22:69-78.
- Slobodchikoff, C.N., S.H. Ackers, and M. Van Ert. 1998. Geographic variation in alarm calls of Gunnisonís prairie dogs. Journal of Mammalogy 79:1263-1272.
- Thomas, D.M., and N.L. Stanton. 1994. Eimerian species (Apicomplexa, Eimeriina) in Gunnisonís prairie dog (Cynomys gunnisoni zuiensis) and Rock squirrels (Spermophilus variegatus grammurus) from southeastern Utah. Journal of the Helminthological Society of Washington 61:17-21.
- Wagner, D.M., and L.C. Drickamer. 2004. Abiotic habitat correlates of Gunnisonís prairie dog in Arizona. Journal of Wildlife Management 68:188-197.
- Written by Theodore G. Manno (PhD student, Auburn University) and Elaine Miller Bond (http://elainebond.home.comcast.net)