Plains harvest mice in tallgrass prairie: abundance, habitat association and individual attributes

TitlePlains harvest mice in tallgrass prairie: abundance, habitat association and individual attributes
Publication TypeJournal Article
Year of Publication2014
AuthorsKaufman, GA, Kaufman, DW
JournalTransactions of the Kansas Academy of Science
Pagination167 -180
Accession NumberKNZ001673
Keywordsabundance, body size, fire effects, Konza Prairie, native tallgrass prairie, Reithrodontomys montanus, reproduction, sex ratio, topography

The plains harvest mouse (Reithrodontomys montanus) inhabits grasslands in the Great Plains, but little is known about its ecology and natural history in native tallgrass prairie. We sampled native tallgrass prairie in spring and autumn by standard traplines on the Konza Prairie Biological Station during autumn 1981-spring 2013 and for shorter time periods in woodlands and brome fields. In addition to our long-term research, we studied small mammals on a large Prairie Grid (∼13 ha) that was trapped intensively (about every 2 weeks except in winter) during 1984–1987. Plains harvest mice (n = 39) were captured in native prairie but not in brome fields or wooded habitats. In all prairie sites, they were found to be rare (1.1 individuals/10,000 trap nights [TN]); in 14 Core Sites sampled for 32 years, abundance was higher in autumn (1.95/10,000 TN) than in spring (0.70/10,000 TN). It was not apparent that these low abundances were related to precipitation or another weather feature. On the Prairie Grid, plains harvest mice were associated with uplands and secondarily with slopes, whereas they avoided lowlands. Furthermore, they showed a positive response to conditions that are created during the first growing season following spring prescribed fires. Overall, 44% of individuals were males and this value did not differ from a 1:1 sex ratio. Non-reproductive females (8.7 g) were slightly larger than males (8.3 g); only females occupied the largest body size class (11.0–11.5 g). The smallest pregnant female weighed 9.0 g, whereas the smallest female that was lactating as evidenced by conspicuous mammae weighed 7.0 g. Pregnancies were recorded in spring, summer and autumn but not in winter; about one-third of females captured were pregnant. A juvenile (5.5 g) was captured in summer. We conclude that to understand this rare species (ca. 0.1% of the small mammal community on Konza Prairie) even studies with small sample sizes are important to elucidate the natural history and ecology of the plains harvest mouse.