SREL Reprint #0361




Avian Versus Mammalian Predation on a Population of Cotton Rats

Richard G. Wiegert



A population of cotton rats (Sigmodon hispidus) in a 1-acre field enclosure was completely protected from predation (April 1965-February 1966) by a cover of nylon net.  Removal of the cover exposed the population to avian predators, but mammalian predators were excluded.  The presence of a cover affected neither seasonal recruitment nor the spring and summer mortality.  However, mortality in autumn-winter, after the peak density of summer, was much lower with the cover in place.  When exposed only to avian predators, the population showed cumulative recruitment and mortality curves similar to those of free-living populations of cotton rats.  The conclusion was that mammalian predators are much less important than avian predators in reducing the annual increment of cotton rats.


SREL Reprint #0361

Wiegert, R.G. 1972. Avian versus mammalian predation on a population of cotton rats. Journal of Wildlife Management 36:1322-1327.

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