Einfluss von Stress während der Individualentwicklung auf die Ausprägung sexuell selektierter Merkmale und Verhalten in Zebra Finken
Zusammenfassung der Projektergebnisse
It is well established that conditions experienced during early development have fundamental effects on the expression of a range of phenotypic and life history traits. Yet, organisms undergo different stages in development and little is known how conditions during each of these stages effects persisting phenotypic traits. This project used zebra finches as model species to experimentally test the role of nutritional conditions during such different developmental stages on a range of traits, mainly sexually selected traits. To achieve this goal we manipulated experimentally nutritional conditions during only the nestling period, only during the fledging period, i.e. when birds have left the nest but are still nutritionally dependent from their parents, or during “puberty”, the period immediately after nutritional independence during which in zebra finches sexual ornaments and mate-trait preferences develop. We then tested the male offspring for song learning, female offspring for song preferences, ran mate choice as well as exploration tests. As physiological correlates of short and long term effects of nutritional stress we conducted RMR measurements, analyzed plasma corticosterone and measured body mass loss after short periods of food deprivation. Overall we showed that nutritional stress during puberty affects attractiveness as well as the expression of sexually selected ornaments whereas we found no such effects for the two earlier developmental periods. Furthermore, we show that birds increase corticosterone during nutritional stress but not during catch-up growth. Yet, catch-up growth resulted in costs apparent in adult exploratory behaviour and adult responses to food shortage. Nestlings were most sensitive to nutritional stress than fledglings. Overall, the combined results off the project emphasize that different developmental periods differently affect phenotypic traits and that animals like zebra finches appear to some extent be well adapted to cope with limited periods of nutritional stress.
Projektbezogene Publikationen (Auswahl)
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2006. Maternal developmental stress reduces reproductive success of female offspring in zebra finches. Proceedings of the Royal Society London B 273: 1901-1905; highlighted in Current Biology 2006: 16(9)R309
Naguib, M., Nemitz, A., Gil, D.
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2007. Living with the past: nutritional stress in juvenile males has immediate effects on their plumage ornaments and adult attractiveness in zebra finches. PLoS one Vol. 2(9), e901
Naguib, M., Nemitz, A.
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2008. Eating like a bird: long term effects of nutritional stress. PhD thesis. University Bielefeld
Honarmand, M.
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2009. Early fasting is long lasting: Differences in early nutritional conditions reappear under stressful conditions in adult female zebra finches. PLoS one 4(3): e5015
Krause, E.T., Honarmand, M., Wetzel, J., Naguib, M.
