@misc{González-Solís_Jacob_Intraindividual_1999, author={González-Solís, Jacob and Becker, Peter H. and Jover, Lluis and Ruiz, Xavier}, editor={Polska Akademia Nauk. Muzeum i Instytut Zoologii}, editor={Meeting of the European Ornithologists' Union (2 ; 1999 ; Gdańsk)}, copyright={Rights Reserved - Restricted Access}, address={Warszawa}, howpublished={online}, year={1999}, language={eng}, language={pol}, abstract={The seasonal decline in egg-volume on the basis of the individual changes in 35 known-age female Common Terns Sterna hirundo was studied with data available for 3-6 years. Interindividual differences were significant for both laying dates and egg-volume. Thus, to examine whether the decline was an effect of an assortment of females with the timing of breeding according to their individual egg-volume, the individual values of laying date were correlated with egg-volume. Correlation was not significant, suggesting that seasonal decline in egg-volume was not due to interindividual differences. Instead, egg-volume showed a gradual decrease with the progress of the season at intraindividual level i.e. the later an individual female laid in the season the smaller was the egg-volume. Moreover, the seasonal decline in egg-volume was not due to a simultaneous increase in egg-volume with an advancement of the timing of breeding with age, since the rate of seasonal decrease in egg-volume was similar for young and old birds. Individual average of laying date accounted for 22% of the individual average of fledgling production whereas egg-volume was not significantly correlated with fledging production. Thus, it is suggested that seasonal decline in egg-volume is a non-adaptive consequence of physiological effect of condition on both timing of breeding and egg-volume.}, type={Text}, title={Intraindividual seasonal decline of egg-volume in common tern Sterna hirundo}, volume={34}, number={2}, journal={Acta Ornithologica}, publisher={Muzeum i Instytut Zoologii PAN}, keywords={Common Tern, eggs, measurement, Germany, Northern, North Sea coast, congresses, individual age, laying date, interindividual differences, egg-volume, terns, birds, Sterna hirundo, Sternidae, Aves}, }