Small Mammal Recolonization of Reclaimed Coal Surface-Mined Land in Wyoming

Abstract

Small mammal populations were compared on unmined rangeland and reclaimed coal surfacemined land reseeded 2 years and 3-5 years previously. Eight species of small mammals were present on the 3-5-year-old reclaimed areas compared with six on 2-year-old areas and five on unmined rangeland. The masked shrew (Sorex cinereus) and northern grasshopper mouse (Onychomys leucogaster) were captured almost exclusively on 3-5-year-old reclaimed land and unmined rangeland. Deer mice (Peromyscus maniculatus) dominated the community on all reclaimed areas in terms of density (13.8 ? 1.2/ha) and biomass (240.1 ? 109.1 g/ha). They composed 93.6 ? 1.9% of all small mammals captured on 2-year-old areas and 83.2 ? 1.1% of those captured on 3-5-year-old areas. Variation in their density paralleled variations in proportions of juveniles on the recolonized areas. Deer mice also were most abundant on unmined rangeland in terms of density, but thirteen-lined ground squirrels (Spermophilus tridecemlineatus) dominated in terms of biomass. Density of recolonizing deer mice stabilized within 2 years after reclamation. After 2 years, total small mammal density remained relatively constant, and diversity of the community increased. J. WILDL. MANAGE. 48(4):1255-1261 The increase in surface mining for coal in the northern Great Plains has generated interest in the ecological processes of reestablishing plant and animal communities in this region. The role of small mammals in undisturbed grasslands has received attention but little is known from reestablished grasslands. Recolonization by small mammals has been investigated on coal mine spoils in eastern and midwestern regions of the United States where repopulation occurs rapidly (Sly 1976, Hansen and Warnock 1978). Revegetation of land in the Great Plains differs from eastern coal lands because of the semiarid climate, low levels of toxic materials, moderate soil acidity, and advanced reclamation technology (Holechek 1982). The objective of this study was to compare community composition and density of small mammals on reclaimed areas of different ages after soil replacement and reseeding. Information from this study was used in an evaluation of the impact of grazing by small mammals on revegetated land (Hingtgen 1982). This research was supported by the USDA For. Serv., Rocky Mt. For. and Range Stn., Res. Work Unit in Rapid City, the AMAX Coal Co., and the USDI Bur. of Mines, under grant G1106002. Any opinions, findings, and conclusions or recommendations expressed in this publication do not necessarily reflect the views of the Bur. of Mines, Dep. of the Inter. We thank R. R. Shinn of AMAX for cooperation during initial phases of the project and acknowledge D. G. Steward, C. H. Sieg, and D. W. Uresk for reviews of the manuscript.