Year: 1995
Type: article
Abstract: ABsTRAc'r.--Total-body electrical conductivity (TOBEC) is a noninvasive technique to estimate body composition in live birds. A comparison of regression models was conducted to identify a useful equation for predicting lean and lipid mass from TOBEC and other variables in three shorebird species (Calidris pusilla, C. alpina and Limnodromus griseus).Models constructed included regressions of lean and lipid mass (independently) on body-mass and bodysize variables, regressions using only TOBEC indices, and expanded models including body mass, size variables, and TOBEC indices.Linear, quadratic, and modified linear (incorporating body length) models were compared to identify the lowest-order polynomial to adequately describe variation in lean and lipid mass within and among species.Prediction intervals (95%) for all regressions were compared to evaluate accuracy of new models.New TOBEC models and TOBEC equations from the literature were used to predict body composition of individuals not included in regression analyses.Modified linear models incorporating body length showed a strong relationship between lean mass and independent variables for two of three intraspecific cases.New and existing TOBEC equations allowed accurate estimates of lean mass.Fat-mass variation was much harder to explain, whether using body-mass and body-size variables or TOBEC indices.With TOBEC it is possible to make accurate predictions of lean mass in live birds, but estimates of fat mass remain problematic.
Authors: James E. Lyons, Susan M. Haig
Language: English
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
Funder: U.S. Fish and Wildlife Service
OpenAlex ID: W2460178004