Habitat availability and animal community characteristics
The microhabitat utilization and niche characteristics of Peromyscus leucopus, Ochrotomys nuttalli, and Blarina brevicauda were examined within a pine plantation on the Oak Ridge National Environmental Research Park (NERP) in East Tennessee. Although general microhabitat utilization was the same, niche parameters (such as niche breadth) for each species varied between two study grids, apparently in response to differing understory density. Specialization is thus proposed to be a function of local microhabitat structure. Removal of the generalist species, P. leucopus, from one grid while maintaining the other as a control elicited a significant microhabitat shift and increase in niche breadth by O. nuttalli. B. brevicauda displayed a slight but nonsignificant microhabitat shift and increased niche breadth. These results are a counter example to the hypothesis that generalist species are poor competitors. Spatial microhabitat heterogeneity created by plant secondary succession and extrinsic disturbances such as tree blow-down is suggested to allow coexistence of these species by altering competitive abilities or microhabitat selection at a small spatial scale. Since interspecific competition affects small mammal niche characteristics, two hypotheses to explain the relative abundances of coexisting animal species are examined. Analysis of the small mammal fauna of the Oak Ridge NERP indicates that habitat availability, not niche breadth, is a good predictor of abundance. This result is discussed in the context of habitat dynamics and the evolutionary history of the species. 103 references, 10 figures, 10 tables.
- Research Organization:
- Oak Ridge National Lab., TN (USA)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 6272235
- Report Number(s):
- ORNL/TM-8864; ON: DE85004945
- Country of Publication:
- United States
- Language:
- English
Similar Records
Microhabitats in a forest-floor small mammal fauna
Patterns of small mammal microhabitat utilization in cedar glade and deciduous forest habitats