Experimental evidence for the role of calcium in eggshell pigmentation pattern and breeding performance in Blue Tits Cyanistes caeruleus

Abstract:

Previous studies have found strong relationships between calcium availability and eggshell pigmentation in the Great Tit (Parus major). According to the “structural function hypothesis”, protoporphyrins, the pigments responsible for reddish spots on speckled eggs, are deposited in those areas of the shell where calcium deposition is less intense. In the study reported here, which was carried out in three Blue Tit (Cyanistes caeruleus) populations in central Spain, we provide partial experimental support for the association between protoporphyrin eggshell pigmentation and shell thinning. Contrary to our expectations, we did not observe a decrease in the size and intensity of pigment spots for those eggs from calcium-supplemented nests. However, we did find that the provision of calcium-rich material during the egg-laying period led to a more wide distribution of pigment spots and reduced the proportion of …

Año de publicación:

2011

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Fuente:

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