Demographic Profiles of Populations of Cotton Rats in a Continuum of Habitat Types

Abstract

We examined temporal relationships between characteristics of populations creatton rats (Sigmodon hispidus) and vegetative characteristics of habitats following secondary succession of post oak (Quercus ste/lata)-blackjack (Q. rnarilandica) savannas in central Oklahoma. Successional changes in vegetation were induced on manipulated habitats by one of two herbicides (tebuthiuron, triclopyr) applied in 1983 and used in combination with or without annual prescribed burning during 1985 to 1988, Relative population density (animals caught per 100 trapnights) and percentage of reproductively active adult females (lactating or pregnant) were significantly greater on manipulated habitats dominated by monocots (grasses) than on habitats with monocots and dieats or undisturbed controls. Herbaceous dicots also influenced the density of cotton rats, especially in 1986; relative density peaked on all manipulated habitats following a peak in production of herbaceous dicots in 1985. Nutritional quality of herbaceous vegetation may have been enhanced by annual burning; relative densities and proportions of juveniles in the trapable population were higher in burned than in unburned habitats. This observation was most pronounced in 1986, when herbaceous dicots comprised a greater proportion ofthe primary production, than in 1987 or 1988.

Implications of Invasion by Juniperus Virginiana on Small Mammals in the Southern Great Plains

“…P. leucopus and N. floridana were captured most frequently in late-successional areas with high amounts of woody dicots, whereas S. hispidus had the highest numbers in earlysuccessional habitats with greater amounts of monocots. Densities of all rodents were higher in early and late succession and lowest in forest habitats with little herbaceous cover (McMurry et al 1993(McMurry et al , 1994(McMurry et al , 1996. These results correspond to our findings that diversity and abundance were lowest in the cross timbers.…”

“…Previous studies at an area adjacent to our study sites found that P. leucopus, S. hispidus, and N. floridana responded to successional changes in habitat (McMurry et al 1993(McMurry et al , 1994(McMurry et al , 1996. P. leucopus and N. floridana were captured most frequently in late-successional areas with high amounts of woody dicots, whereas S. hispidus had the highest numbers in earlysuccessional habitats with greater amounts of monocots.…”

“…Goertz (1964) also found that this species usually avoids areas where tree canopy shades ground cover. At an area adjacent to our study sites, relative densities of S. hispidus increased in response to increased production of monocots (McMurry et al 1994). When red cedar colonizes an area, it reduces the herbaceous ground cover under the canopy zone (Engel et al 1987;Smith and Stubbendieck 1990) on which prairie mammals depend.…”

Adult bobcat (Lynx rufus) habitat selection in a longleaf pine savanna

“…Selection of young pines in the Mississippi studies was primarily due to relative abundance of small mammals in young pines (Conner 1991, Conner et al 1992. Many young pines in our study area contained little herbaceous vegetation and few small mammals (Golley et al 1965, Schnell 1968, McMurry et al 1994, Masters et al 1998, which may explain why bobcats were farther from young pines.…”

“…In a system managed by frequent fire return intervals (≤ 3 years), herbaceous plant communities do not shift to dense hardwood understory communities (Glitzenstein et al 2012). Therefore, these systems contain diverse understory plant communities (Brockway and Lewis 1997), which can produce abundant small mammal populations (Golley et al 1965, Schnell 1968, McMurry et al 1994, Masters et al 1998. We suspect bobcats selected mature pine and mixed pine-hardwoods due to the availability of prey (see also Sasmal et al 2017); however, we lack data on prey availability among the vegetation types on our study area.…”