THE RELIABILITY OF FAT SCORES AS PREDICTORS OF THE MASS OF FAT CARRIED BY INDIVIDUAL BIRDS

Fat scoring is a widely used technique for quantifying the amount of s tored lipid in populations of live birds. We assessed its effectivenes s for use on individuals by comparing fat scores of migratory Rinsed P lover Charadrius hiaticula with measures of total fat content predicte d by total body electrical conductivity (TOBEC). The 4-point fat score used proved to be a reliable indicator of average lipid levels in gro ups of birds and was independent of total body size. There was however , considerable variation in the predicted fat mass between individuals assigned to the same fat score and large overlap existed in the range s of predicted fat mass between different fat scores. Fat scores are t herefore a poor indicator of lipid levels predicted by TOBEC in indivi dual birds.