PARENT SESSION
Oral Session #4: Animal Population Ecology.
Presiding: L. Mitchell
Monday, August 5. 8:00 AM to 11:30 AM. Gila Meeting Room, TCC.

Long-term study of small mammals in tallgrass prairie: prairie voles and southern bog lemmings.

Kaufman, Donald^*,1, Kaufman, Glennis¹, ¹ Kansas State University, Manhattan, KS

ABSTRACT- As part of the Konza Prairie LTER Program, we initiated an ongoing study of small mammals in 1981 from which 13 species of rodents and shrews have been recorded. Our ongoing sampling of spring and autumn populations is conducted at 14 permanent sites, which represent an array of fire regimes, located within a 1,000-ha area of tallgrass prairie at Konza Prairie Biological Station. Here, we focus on two herbivorous rodents, prairie vole (Microtus ochrogaster) and southern bog lemming (Synaptomys cooperi). Voles were several times more abundant (individuals/trapline) in autumn (mean: 0.98, range: 0.0-6.0) than were bog lemmings (mean: 0.14, range: 0.0-0.9). The same pattern was true in spring for voles (mean: 0.54, range 0.0-3.7) and bog lemmings (mean: 0.09, range: 0.0-0.7). These values rank the two species as the fifth and eighth most abundant species in autumn and fourth and sixth in spring. Patterns of abundance demonstrate that both species respond negatively to prairie fires. Further, the temporal pattern of autumn abundance of prairie voles has been consistent with an expected cyclic pattern as peaks occurred in 1982, 1985, 1990, 1993, and 1998. Bog lemmings match this pattern except in 1998. Finally, autumn abundances of both species in peak or near-peak years appear to be constrained by primary productivity, but this is not true for populations in other years.

KEY WORDS: small mammals, population ecology, long-term ecological research, tallgrass prairie