Intraindividual seasonal decline of egg-volume in common tern Sterna hirundo

• Main Authors: González-Solís, Jacob, Becker, Peter H., Jover, Lluis, Ruiz, Xavier
• Other Authors: Polska Akademia Nauk. Muzeum i Instytut Zoologii, Meeting of the European Ornithologists' Union (2, 1999, Gdańsk)
• Format: Text
• Language: English; Polish
• Published: Muzeum i Instytut Zoologii PAN 1999
• Subjects: Common Tern; eggs; measurement; Germany; Northern; North Sea coast; congresses; individual age; laying date; interindividual differences; egg-volume; terns; birds; Sterna hirundo; Sternidae; Aves; Rybitwa rzeczna > jaja > pomiar > Niemcy Północne > konferencje [KABA]; różnice międzyosobnicze; wybrzeże Morza Północnego; rybitwy; ptaki; Common tern
• Online Access: https://rcin.org.pl/dlibra/publication/edition/45218/content

Referat wygłoszony na Second Meeting of the European Ornithologists' Union Bibliogr. p. 189-190 P. [185]-190 : ill. 27 cm Streszcz. pol. Abstract in Polish 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. Referat wygłoszony na Second Meeting of the European Ornithologists' Union Bibliogr. s. 189-190 S. [185]-190 : il. 27 cm Streszcz. pol. 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 ...