An evaluation of condition indices for birds
January 1, 1985
A Lipid Index, the ratio of fat to fat-free dry weight, is proposed as a measure of fat stores in birds. The estimation of the index from field measurements of live birds is illustrated with data on the sandhill crane (Grus canadensis) and greater white-fronted goose (Anser albifrons). Of the various methods of assessing fat stores, lipid extraction is the most accurate but also the most involved. Water extraction is a simpler laboratory method that provides a good index to fat and can be calibrated to serve as an estimator. Body weight itself is often inadequate as a condition index, but scaling by morphological measurements can markedly improve its value.
Citation Information
Publication Year | 1985 |
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Title | An evaluation of condition indices for birds |
Authors | D. H. Johnson, G.L. Krapu, K. J. Reinecke, Dennis G. Jorde |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Journal of Wildlife Management |
Index ID | 1001568 |
Record Source | USGS Publications Warehouse |
USGS Organization | Northern Prairie Wildlife Research Center |