Predicting Presence and Abundance of a Small Mammal Species: The Effect of Scale and Resolution

Abstract

Management of small mammal communities in forest ecosystems requires a working knowledge of the scales at which species presence and abundance can best be predicted. Habitat-based models were developed to characterize the distribution of a boreal relict, the southern red-backed vole, Clethrionomys gapperi, in the southern Appalachian Mountains, USA, at three hierarchical scales of analysis. Vole presence and abundance were most evident at the high-resolution (macrohabitat) scale, followed by the intermediateresolution scale. The low-resolution model was the least effective for predicting presence or abundance and reflects the need for more resolute landscape classification systems if small mammal populations are to be accounted for in an ecologically relevant manner. Tree and shrub communities indicative of suitable vole habitat included Fraxinus pennsylvanica and Tsuga canadensis in the canopy and Carpinus caroliniana in the understory. Vole abundance increased with incidence of tree species such as Betula alleghaniensis, Pinus rigida, and Prunus serotina in the canopy, and Acer spicatum and woody vines in the understory. Voles were associated with northwest-facing high-elevation sites with abundant rocky substrate, likely a reflection of physiological water and thermal requirements, biogeographic influences, and the importance of substrate complexity for decreasing inter-and intraspecific interactions and avoidance of predators.Identification of the most effective resolution of landscape characterization improves habitat-based models of C. gapperi population dynamics in managed landscapes. Lowresolution habitat classifications may suffice for detecting suitable vole habitats within forest types, but prediction of vole abundance is most accurate at the greatest resolution, i.e., the macrohabitat scale. The utility of forest communities and habitats at various scales to predict vole presence and abundance suggests that C. gapperi may be a useful indicator species for identification and assessment of habitat important for rare small mammal species in the southern Appalachians.

‘Invasional meltdown’: evidence for unexpected consequences and cumulative impacts of multispecies invasions

“…For example, similar landscape and habitat effects (e.g. Andrews and O'Brien 2000;Orrock et al 2000;Panzacchi et al 2010) and negative interspecific interactions (e.g. Fox and Fox 2000;Eccard and Ylonen 2003;Morris 2005) have been revealed in well established small mammal communities.…”

Rabbit populations and game management: the situation after 15 years of rabbit haemorrhagic disease in central-southern Spain

“…However, the variables we considered and the way that they were measured could be masking the importance of vegetation cover on rabbit population change. Furthermore, another important issue to consider in studies of the influence of vegetation cover is the role of scale (Orrock et al 2000). Silva et al (2005) suggested that microhabitat characteristics tend to influence small mammals at the population level while macrohabitat and landscape features are important determinants of small mammals especially at the community level.…”

An appraisal of the fitness consequences of forest disturbance for wildlife using habitat selection theory

“…1b-d, where D is replaced by the percent difference in browse availability between cut and uncut stands), which represents their main source of food during winter (Pease et al 1979). Red-backed voles have high water requirements (Getz 1968) and are most commonly associated with mesic forest habitats with moist microclimates provided by coarse woody debris, shrubs and moss cover (Morris 1996;Orrock et al 2000). We therefore tested additional isodar models for voles that included moss cover as a measure of microhabitat moisture (i.e., scenarios in Fig.…”