A Physiological Condition Index for Wintering Mallards

Publisher Website
Google Scholar
Abstract
Mallards (A. platyrhynchos) were collected during winter 1982-1983 in eastern Colorado [USA] and subjected to whole-carcass analysis to determine carcass composition and develop a physiological condition index. Condition index was defined as body fat/fat-free body weight. Multiple regression equations using body weight and wing length were highly correlated with total body fat in male (R2 = 0.643) and female (R2 = 0.679) mallards. When tested on an independent data set,fat predictor equations accurately estimated measured body fat (R2 = 0.769). Weight and wing measurements were easily obtained on live mallards under field conditions with high repeatability among observers (CV [coefficient of variation] < 1%). By accounting for variability in structural size among birds, models were able to detect differences in body condition that were not detectable using body weight alone.

This publication has 10 references indexed in Scilit: