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An Experimental Study of Dispersal of the Cotton Rat, SIGMODON HISPIDUS

Dispersal of cotton rats was examined over an annual cycle of abundance by removal trapping in pine flatwoods. All cotton rats live-trapped at biweekly intervals on two 0.49 ha grids were removed, whereas rats on an adjacent control grid were tagged an released alive on site. The null hypothesis was that dispersing cotton rats would represent a random sample of sex and weight (age) classes from source populations, e.g. the control grid. Likewise, it was assumed that dispersal rates would be proportional to numerical changes in abundance on the control grid. Dispersing animals were clearly most prevalent on the removal grids during November and December 1979 when numbers of rats on the control grid were increasing. Breeding ceased in December and fewer animals dispersed between January and May. The cumulative number of individual animals captured or removed from the study grids (control and removals) was remarkably similar. The proportion of individuals removed according to weight class was not significantly different among grids. Sex ratios of rats on the control and removal grids were not different from 50:50 (P > 0.05). The conclusion is that dispersing cotton rats represented a cross-section of age groups and sexes. The results support the rank-order template hypothesis as the dispersal strategy of the cotton rat. Genetic and behavioral differences between dispersers and source populations could not be discriminated with the methodology employed.

Identiferoai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:rtd-1594
Date01 April 1981
CreatorsStafford, Stephen R.
PublisherSTARS
Source SetsUniversity of Central Florida
LanguageEnglish
Detected LanguageEnglish
Typetext
Formatapplication/pdf
SourceRetrospective Theses and Dissertations
RightsPublic Domain

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