Population dynamics of hispid cotton rats (Sigmodon hispidus) across a nitrogen-amended landscape

Canadian Journal of Zoology
By: , and 



We conducted a mark-recapture experiment to examine the population dynamics of hispid cotton rats (Sigmodon hispidus) in response to low-level nitrogen amendments (16.4 kg nitrogen/ha per year) and exclosure fencing in an old-field grassland. The experimental design consisted of sixteen 0.16-ha plots with 4 replicates of each treatment combination. We predicted that densities, reproductive success, movement probabilities, and survival rates of cotton rats would be greater on nitrogen-amended plots because of greater aboveground biomass and canopy cover. Population densities of cotton rats tended to be highest on fenced nitrogen plots, but densities on unfenced nitrogen plots were similar to those on control and fenced plots. We observed no distinct patterns in survival rates, reproductive success, or movement probabilities with regard to nitrogen treatments. However, survival rates and reproductive success tended to be higher for cotton rats on fenced plots than for those on unfenced plots and this was likely attributable to decreased predation on fenced plots. As low-level nitrogen amendments continue to be applied, we predict that survival, reproduction, and population-growth rates of cotton rats on control plots, especially fenced plots with no nitrogen amendment, will eventually exceed those on nitrogen-amended plots as a result of higher plant-species diversity, greater food availability, and better quality cover.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Population dynamics of hispid cotton rats (Sigmodon hispidus) across a nitrogen-amended landscape
Series title Canadian Journal of Zoology
DOI 10.1139/z03-084
Volume 81
Issue 6
Year Published 2003
Language English
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Canadian Journal of Zoology
First page 994
Last page 1003
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