Population dynamics of a diverse rodent assemblage in mixed grass-shrub habitat, southeastern Colorado, 1995-2000.
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. Inter-annual 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.
Calisher
Charles H
CH
Arthropod-borne and Infectious Diseases Laboratory, Foothills Campus, Colorado State University, Fort Collins, Colorado 80523, USA. calisher@cybercell.net
Mills
James N
JN
Sweeney
William P
WP
Root
J Jeffrey
JJ
Reeder
Serena A
SA
Jentes
Emily S
ES
Wagoner
Kent
K
Beaty
Barry J
BJ
D000818:Animals; D002980:Climate; D003120:Colorado; D005260:Female; D005843:Geography; D008297:Male; D010802:Phylogeny; D011156:Population Density; D011157:Population Dynamics; D012377:Rodentia / Q000145:classification* / Q000254:growth & development* / Q000502:physiology; D012621:Seasons