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Radiation LD50 (30) of Pikas (Ochotona princeps) in the Natural Environment and in Captivity
O. D. Markham and F. W. Whicker
The American Midland Naturalist
Vol. 84, No. 1 (Jul., 1970), pp. 248-252
Published by: The University of Notre Dame
Stable URL: http://www.jstor.org/stable/2423742
Page Count: 5
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Estimates of the LD50(30) from 60Co radiation were made for a group of pikas (Ochotona princeps) held in captivity and for another group observed in the natural environment near the summit of Mount Evans, Colorado. The LD5030 estimate was 560 r (438-717 r; 95% confidence limits) for captive animals and 380 r (250-578 r) for pikas at Mount Evans. Mean survival time for irradiated pikas was 9 to 13 days in captivity and 5 to 7 days in the natural environment. Results are discussed in relation to artificial stresses resulting from captivity and natural stresses such as intraspecific competition and predation.
The American Midland Naturalist © 1970 The University of Notre Dame