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Journal

University of Northern Iowa

2000

Algific slopes

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Full-Text Articles in Life Sciences

Population Size Estimates For The Endangered Iowa Pleistocene Snail, Discus Macclintocki Baker, Tama K. Anderson Jan 2000

Population Size Estimates For The Endangered Iowa Pleistocene Snail, Discus Macclintocki Baker, Tama K. Anderson

Journal of the Iowa Academy of Science: JIAS

Discus macclintocki Baker, the Iowa Pleistocene snail, is a federally endangered species found only on algific talus slopes in northeastern Iowa and northwestern Illinois. Population size estimates for fourteen D. macclintocki populations in Iowa and Illinois ranged from 182 to 22,125 individuals. Estimates from the program CAPTURE as well as Bayesian estimation procedures gave similar results, although the Bayesian method allowed estimation of populations that could not be estimated with CAPTURE due to small sample sizes. A comparison of two methods of sampling, visual counts of quadrats and cover boards, showed that using cover boards resulted in much higher probabilities …