SREL Reprint #0172




An Evaluation of the Proposed International Biological Program Census Method for Estimating Small Mammal Populations

John B. Gentry, Frank B. Golley and Michael H. Smith



Polish workers have proposed a method of estimating small rodent populations based on removal trapping. Using a linear regression method, they obtained reliable population estimates with five days of prebaiting followed by five days of removal trapping. The aim of our study was to compare the results obtained, using the same method at the Atomic Energy Commission's Savannah River Plant in the South-eastern United States, with the results of the Polish investigators. Our study area consisted of 5.8 ha over which a grid of 256 trap stations was arranged with two-snap traps at each station. Since by the filth day of trapping, the number of daily captures had not declined, the trapping period was extended to cover 27 days. An increase in daily captures was observed between the 13th and 15th day in three of the four most common species. These fluctuations in capture rates were believed to be due to behavioral changes in the population. The results from this study indicated that at last nine days of trapping were necessary to obtain reliable estimates for the population as a whole. Even so, reliable estimates could not be calculated for two of the four most common species after 27 days of removal trapping.


SREL Reprint #0172

Gentry, J.B., F.B. Golley, and M.H. Smith. 1968. An evaluation of the proposed International Biological Program census method for estimating small mammal populations. Acta Theriologica 13:313 327.

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