OUP user menu

An Eleven Year History of a Sigmodon Population

Eugene P. Odum
DOI: http://dx.doi.org/10.2307/1375679 368-378 First published online: 1 August 1955

While general observation has indicated that annual fluctuations in population density of rodents in southern United States are less “cyclic,” i.e., peaks less regular, than is the case in the classic northern four-year cycles, few long-term observations have been made on populations in stable habitats. The possibility of a north-south difference in the nature of population oscillations has an important bearing on current theories of “cycles.” For the past eleven years trapping has been carried out according to a consistent plan in an old field where habitat features have been relatively constant. The field is located near Athens, Clarke County, Georgia in the Piedmont section of the state. The cotton rat, Sigmodon hispidus, comprised the great bulk of the readily trappable small mammal population in the old field, which is in a stage of vegetative succession favorable to the species. (Cotton rats occurring in Georgia except for the coastal strip, below 100 foot contour line, have been assigned to the subspecies Sigmodon hispidus komareki by Gardner, 1948.) Results of this study are presented simply as evidence of changes in density, natality, age distribution and other population characteristics that apparently have occurred on a limited area. No attempt will be made at this time to interpret these data in terms of various theories that have been advanced to explain population cycles.

The writer is indebted to the following students and former students who helped with trap setting and specimen preparation at various times during the period: Drs. Robert A. Norris and David W. Johnston, James C. Major, H. C. Robert, James O. Harrison, Edward J. Kuenzler, Jack Lowe, and J. B. Gentry.

The study area.—The old field selected for this study (PL I) is one of a series of abandoned fields lying on a slope a quarter of …

View Full Text

Sign in

Log in through your institution

Sign in as a personal subscriber

Log in through your institution

Purchase a personal subscription