Population Dynamics of a Diverse Rodent Assemblage in Mixed Grass-Shrub Habitat, Southeastern Colorado, 1995–2000

Abstract

We followed seasonal and year-to-year population dynamics for a diverse rodent assemblage in a short-grass prairie ecosystem in southeastern Colorado (USA) for 6 yr. We captured 2,798 individual rodents (range, one to 812 individuals per species) belonging to 19 species. The two most common species, deer mice (Peromyscus maniculatus) and western harvest mice (Reithrodontomys megalotis), generally had population peaks in winter and nadirs in summer; several other murid species demonstrated autumn peaks and spring nadirs; heteromyids were infrequently captured in winter, and populations generally peaked in summer or autumn. Interannual trends indicated an interactive effect between temperature and precipitation. Conditions associated with low rodent populations or population declines were high precipitation during cold periods (autumn and winter) and low precipitation during warm periods (spring and summer). Severity of adverse effects varied by species. Heteromyids, for example, were apparently not negatively affected by the hot, dry spring and summer of 2000. Cross-correlations for the temporal series of relative population abundances between species pairs (which are affected by both seasonal and interannual population dynamics) revealed positive associations among most murids and among most heteromyids, but there were negative associations between murids and heteromyids. These results have important implications for those attempting to model population dynamics of rodent populations for purposes of predicting disease risk.

Environmental factors and population fluctuations of Akodon azarae (Muridae: Sigmodontinae) in central Argentina

“…On the other hand, the annual decline in rodent populations has been attributed to loss of cover, reduction of food resources, frosts and low temperatures that cause an increase of mortality and cessation of reproduction (Crespo 1966; Garsd & Howard 1981, 1982; Mills et al . 1991, 1992; Calisher et al . 2005).…”

“…1997), daily activity (Vickery & Bider 1981) and habitat use (Vickery & Rivest 1992). Furthermore, high temperatures may promote or suppress reproductive activity in rodents according to the moment of occurrence (Adamczewska‐Andrsejewska 1979; Garsd & Howard 1981; Calisher et al . 2005; Liu et al .…”

Potential Influence of Climate Change on Vector-Borne and Zoonotic Diseases: A Review and Proposed Research Plan

“…The PDO resulted in precipitation increases (Ari et al 2008) that were believed to enhance small-mammal food resources and flea survival (Enscore et al 2002; Parmenter et al 1999). Although less attention has been paid to decreases in host populations, lower rainfall is accompanied by decreasing populations of North American deer mice in the southwestern United States (Yates et al 2002), whereas increasing rainfall during cold periods was associated with abrupt population declines in some ecosystems (Calisher et al 2005). …”

“…Contrary to what was observed in New Mexico, the 1997 ENSO did not lead to a net increase in North American deer mouse populations at a high-altitude site in Colorado. Increases in abundance of North American deer mice in Colorado from 1995 to 2000 were associated with increased rainfall during warm periods, but populations crashed after increased rainfall during cold periods (Calisher et al 2005). Similarly, the combined effects of temperature and humidity affect the behavior, survival, and reproduction of many vector species.…”

Modelling the Bioclimatic Niche and Distribution of the Steppe Mouse, Mus Spicilegus (Rodentia, Muridae), in Ukraine

“…Similar critical weather episodes in winter and early spring have also been suggested to dramatically reduce winter survival in small mammals. For instance, deer mouse (Peromyscus maniculatus) populations in Colorado responded favourably to rainfall during warm periods, but crashed when high rainfall occurred during cold periods (Calisher et al, 2005;Luis et al, 2010). In our case winter survival of the species most likely depends on the combination of temperature and precipitation, when the ambient temperature is not too low (to avoid freezing), but not too high (to perhaps trigger snow melting), and less precipitation the better.…”