- Tytuł:
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Decline of egg volume in common tern
Spadek wielkości znoszonych jaj jako cecha osobnicza u rybitwy rzecznej
Intraindividual seasonal decline of egg-volume in common tern Sterna hirundo
Acta Ornithologica, vol. 34, no. 2 - Autorzy:
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Ruiz, Xavier
González-Solís, Jacob
Becker, Peter H.
Jover, Lluis - Współwytwórcy:
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Meeting of the European Ornithologists' Union (2 ; 1999 ; Gdańsk)
Polska Akademia Nauk. Muzeum i Instytut Zoologii - Wydawca:
- Muzeum i Instytut Zoologii PAN
- Powiązania:
- Acta Ornithologica
- Opis:
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Bibliogr. s. 189-190
P. [185]-190 : ill. ; 27 cm
Bibliogr. p. 189-190
S. [185]-190 : il. ; 27 cm
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.
Abstract in Polish
Streszcz. pol.
Referat wygłoszony na Second Meeting of the European Ornithologists' Union - Dostawca treści:
- RCIN - Repozytorium Cyfrowe Instytutów Naukowych
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