Discrimination of Ross's and lesser snow goose eggs / Ray T. Alisauskas, Stuart M. Slattery, John P. Ryder, Mark L. Gloutney, Alan D. Afton, Richard H. Kerbes, and M. Robert McLandress.
Material type:
TextSeries: Journal of Field Ornithology. 69(4) 647-653 Publication details: 1998.Description: 28 cmLOC classification: - ALI
| Item type | Current library | Collection | Call number | Status | Date due | Barcode |
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Electronic Journal
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IWWR Supported Research | Non-fiction | ALI (Browse shelf(Opens below)) | Available | 16842 |
Includes bibliographical references (pages 652-653).
Our objeClive was to assess whether egg measurements could be used to discriminate
accurately eggs of Ross's (Chen TOssii) and Lesser Snow Geese (Chen caerulescens caeTulescens).
We used lengths and widths of eggs found in nests of known species at Arlone
Lake in 1963 and Karrak Lake, Northwest Territories, in 1968, 1976, 1988, and 1991-1996.
Although accuracy of classification varied slightly among years, discriminant function analyses
were 89-]00% successful in identifying species based on dimensions of individual eggs and
clutch means. Bias in estimates of species ratios, which reflects combined effects of misclassificalions
in both species, was only 2% in favor of Ross's Geese when all years were pooled.
We conclude thal classification equations, derived from discriminant function analyses using
known-species eggs, are reliable and objective techniques for determining species of eggs
and nests of unknown origin at Ross's and Snow Goose colonies.