Holarctic Marmots as a factor of Biodiversity.
Rumiantsev V.Yu;, Nikol'skii A.A. & Brandler O.V. eds.,
3d Conference on Marmots (Cheboksary, Russia, 25-30 August 1997),
Moscow ABF 1997, 216p. : 190-191.
EMPIRICAL CONSIDERATIONS ON THE STABLE AGE DISTRIBUTION
O.A. Schwartz*, K.B. Armitage**
* Department of Biology, University of Northern Iowa
** Department of Systematics and Ecology, The University of Kansas, Lawrence,
We tested the statistical equivalence of time-specific and cohort-specific life tables of the yellow-bellied marmot (Marmota flaviventris) using 24 yr of data. Birth and death pulses moved diagonally through the annual age distributions. Litter sizes were heterogeneous among years. The crude death rate, gross reproductive rate, and population growth rate were normally distributed with no outlying points. Using all years and in paired comparisons between years the Kolmogorov-Smirnov and Kruskal-Wallis statistics were deemed unsuitable for comparisons of the relative proportions in age classes. Chi-square tests of absolute frequencies showed overall heterogeneity
in the 24 yr sample and in 46% of yearly paired comparisons, but the power of the test for this application is unknown. Time-specific and cohort-specific
life tables were not equivalent in marmots and reanalysis of life tables of Belding's ground squirrel (Zammuto and Sherman 1986) produced the same conclusion.
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