Data from: Evolutionary design of a flexible, seasonally migratory, avian phenotype: why trade gizzard mass against pectoral muscle mass? ...

• Main Authors: Mathot, Kimberley, Kok, Eva, Burant, Joseph, Dekinga, Anne, Manche, Petra, Saintonge, Darren, Piersma, Theunis
• Format: Dataset
• Language: English
• Published: Dryad 2019
• Subjects: flexible phenotype; Calidris canutus islandica; trade-offs; evolved mechanisms; body remodelling; trait covariance; Calidris canutus
• Online Access: https://dx.doi.org/10.5061/dryad.48894fk; https://datadryad.org/stash/dataset/doi:10.5061/dryad.48894fk

Migratory birds undergo impressive body remodelling over the course of an annual cycle. Prior to long-distance flights, red knots (Calidris canutus islandica) reduce gizzard mass while increasing body mass and pectoral muscle mass. Although body mass and pectoral muscle mass are functionally linked via their joint effects on flight performance, gizzard and pectoral muscle mass are thought to be independently regulated. Current hypotheses for observed negative within-individual covariation between gizzard and pectoral muscle mass in free-living knots are based on a common factor (e.g., migration) simultaneously affecting both traits, and/or protein limitation forcing allocation decisions. We used diet manipulations to generate within-individual variation in gizzard mass and test for independence between gizzard and pectoral muscle mass within-individuals outside the period of migration and under conditions of high protein availability. Contrary to our prediction, we observed a negative within-individual ... : knot_covarianceData file with all measurements of knot body body mass, pectoral muscle mass and gizzard mass. First tab within the excel sheet provides detail on each column in the main data table. ...