Body mass and wing length of nestling Redstart Phoenicurus phoenicurus in a harsh northern environment

Abstract

Using mean brood values, the growth of nestling Redstarts was studied in relation to reproductive and environmental variables in a northern marginal area (Finnish Lapland) . During three years the mean values of the growth variables did not vary significantly annually . The asymptote and the growth constant of the logistic body-mass curve correlated significantly with each other. Nesdings from large eggs reached the inflection pointof the logistic body-mass curve sooner than nestlings from small eggs. Largeegg size andwarm weather during the nestling period hadpositive effects on wing growth . Brood size and the date of hatching did not affect the growth of nestlings. The results are compared with growth data on Pied Flycatcher Ficedula hypoleuca nestlings from the same area