Using Survival of Rodents to Assess Quality of Prairie Habitats

Influence of vegetation structure on the small mammal community in a shortgrass prairie ecosystem

“…Northern grasshopper mice, kangaroo rats, and ground squirrels were more often found in areas with a high percentage of bare ground while pocket mice were found in areas free of vegetative litter. These approximate patterns are similar to those reported in other landscapes; pocket mice are generally found in low numbers across a range of habitats but prefer arid areas with sparse vegetation, Ord's kangaroo rats and ground squirrels prefer sparse litter, and deer mice are generalists (Kaufman et al 2000;Schorr et al 2007). In general, the richest and most diverse rodent communities were found in areas of reduced litter cover and some degree of structural heterogeneity.…”

“…Other studies have reported similar patterns, with larger bodied species such as kangaroo rats being the dominant foragers in open, intershrub space (Brown and Liebermann 1973;Rosenzweig 1973;Schorr et al 2007) due to their suite of anti-predator adaptations including social behavior (Bartholomew and Caswell 1951;Webster and Webster 1971) and bipedal movement (Longland and Price 1991). Areas of thick vegetation and litter are typically characterized by small, seed-eating mice such as deer mice (Kaufman et al 2000;Schorr et al 2007) whose solitary behavior and quadrapedal movement may restrict their habitat use (Longland and Price 1991;White et al 2004). Reed et al (2005) reported that rodents foraging for seeds in areas with sparse litter are searching for seeds in a two-dimensional environment, while areas with litter must forage in a three-dimensional environment.…”

“…However, as sites were gradually converted to shrubland, community dominance shifted to more abundant, smaller bodied species such as pocket mice or grasshopper mice. Other studies have reported similar patterns, with larger bodied species such as kangaroo rats being the dominant foragers in open, intershrub space (Brown and Liebermann 1973;Rosenzweig 1973;Schorr et al 2007) due to their suite of anti-predator adaptations including social behavior (Bartholomew and Caswell 1951;Webster and Webster 1971) and bipedal movement (Longland and Price 1991). Areas of thick vegetation and litter are typically characterized by small, seed-eating mice such as deer mice (Kaufman et al 2000;Schorr et al 2007) whose solitary behavior and quadrapedal movement may restrict their habitat use (Longland and Price 1991;White et al 2004).…”

“…Reasons for this low explanatory power in our models are varied. Other factors such as floristics, soil characteristics (Harrison and Bardgett 2010), or level of seed predation, while related to vegetation structure or microhabitat, may play a greater role in explaining small mammal community composition (Reed et al 2005;Schorr et al 2007). Reed and Slade (2009) found no relationship between environmental variability and vital rates (survival and reproduction) of prairie voles (Microtus ochrogaster).…”

“…were more important in structuring rodent communities than vegetation cropping. Predation of rodents by native mesocarnivores could also shape rodent survival rates (Schorr et al 2007) and rodent community diversity (Henke and Bryant 1999), which would not be evident in data collected from trapping grids.…”