REFINED METHODS FOR ASSESSMENT OF NUTRIENT RESERVE USE AND REGULATIONOF CLUTCH SIZE

Methods for evaluating regulation of clutch size by endogenous nutrien ts have evolved rapidly over the last decade. Use of regression and co rrelation approaches to estimate rate of depletion of nutrient reserve s and to test hypotheses about regulation of clutch size represented s ignificant advances. Assessment of relationships between nutrient rese rves and clutch size have been substantially improved by controlling f or both body size and laying date. We point out potential biases and s purious correlations in current hypothesis tests, which examine the re lationship between remaining nutrient reserves and remaining rapidly d eveloping follicles. We recommend new methods to control for clutch si ze and for estimation of depletion of nutrient reserves, and for testi ng hypotheses regarding clutch size regulation.