Distribution of the middorsal stripe dimorphism in the wood frog, Rana sylvatica , in eastern North America

The frequency of the middorsally striped morph of Rana sylvatica in Ontario and Manitoba varies from absence in southern Ontario to 80% on the coast of Hudson Bay, with a general value of 20–30% in the boreal forest, a rise to 50% on the forest–grassland ecotone in southern Manitoba, and a decline w...

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Bibliographic Details
Published in:Canadian Journal of Zoology
Main Authors: Schueler, Frederick W., Cook, Francis R.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1980
Subjects:
Online Access:http://dx.doi.org/10.1139/z80-226
http://www.nrcresearchpress.com/doi/pdf/10.1139/z80-226
Description
Summary:The frequency of the middorsally striped morph of Rana sylvatica in Ontario and Manitoba varies from absence in southern Ontario to 80% on the coast of Hudson Bay, with a general value of 20–30% in the boreal forest, a rise to 50% on the forest–grassland ecotone in southern Manitoba, and a decline westward to 20% on the edge of the prairies. This morph is rare in the northeastern United States and Maritime Canada. The suggested relationship between its frequency and the "grassiness" of the background on which predators view it is reexamined, and it is suggested that a linkage with earlier transformation as demonstrated in Eurasian species may explain certain anomalies.