| population ecology group | ::: | institute | ::: | university | ::: |  |
| Dr Joanna Rutkowska joanna.rutkowska@uj.edu.pl |
Inst. of Environmental Sciences Jagiellonian University Gronostajowa 7, 30-387 Kraków Poland tel. + 48 12 664 51 99 fax + 48 12 664 69 12 |
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Offspring sex determination: integrating ecological context and proximate mechanism of non-random meiosis in birds
In this project, I test the hypothesis that the proximate mechanism behind adaptive offspring sex adjustment in birds is the hormone-induced non-random chromosome segregation during meiosis (Rutkowska & Badyaev 2008). As a model system, I've used the House finch (Carpodacus mexicanus) and now I study the Japanese quail (Coturix japonica).
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House finch pair photo: Alex Badyaev |
Cooperation: Alex Badyaev (University of Arizona), Elizabeth Adkins-Regan (Cornell University).
Reproductive strategies in an urban population of the European blackbird (Turdus merula)
We found increased maternal investment to sons versus daughters expressed in egg sexual size dimorphism (Martyka et al. in review). This phenomenon can be explained in light of higher fitness variation of males in the European blackbird. Currently, we are studying the relationship between mate switching and extra-pair paternity in this species.
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Blackbird nest photo: Kazimierz Walasz |
Cooperation: Kazimierz Walasz, Mariusz Cichoń, Rafał Martyka, Anna Dybek (Institute of Environmental Sciences), Artur Jarmołowski, Marlena Lembicz and Artur Rogowski (Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University).
Heritability of immune response and costs of immunocompetance in birds
We are interested in life-history trade-offs of immunological competence. Specifically, we study the significance of heritable and maternally transmitted components of immunity. Research is conducted using non-pathogenic inoculations in the Zebra finch.
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Zebra finch family photo: Joanna Rutkowska |
Cooperation: Mariusz Cichoń, Rafał Martyka (Institute of Environmental Sciences).
Completed projects:
The effect of testosterone on primary sex ratio and on performance of male and female offspring in the zebra finches (Taeniopygia guttata)
We found the cause-and-effect relationship between maternal androgens and proportion of sons among offspring (Rutkowska & Cichoń, 2006) and showed that elevated androgen level might have negative effects on the mother (Rutkowska et al. 2005). We aslo showed how maternal androgens affect survival, development and reproductive success of male and female offspring (Rutkowska et al. 2007).
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Zebra finches in the nest photo: Joanna Rutkowska |
Resources quality and sex allocation in zebra finches (Taeniopygia guttata)
We found that female birds react to the immediate change in food quality during clutch formation by adjusting sex of subsequently laid eggs within a clutch (Rutkowska and Cichoń, 2002). It shows that female birds control offspring sex to the great extend. We also found that the increase of egg mass with the laying sequence compensates for the negative effects of hatching asynchrony. Sex allocation may influence competition among offspring in asynchronously hatching broods (Rutkowska and Cichoń 2005).
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Zebra finch hatchling photo: Joanna Rutkowska |
Cooperation: Mariusz Cichoń
Costs of rearing sons versus daughters in the bank vole (Clethrionomys glareolus)
In year 2003 I took part in the studies of maternal investment to male and female offspring in mammals, in the project of Drs Tapio Mappes and Esa Koskela at the Jyväskylä University (Finland). We found that female bank vole invest more in daughters than in sons. It was expressed in higher milk production and more vigorous nest defence behaviour. Our results revise the common assumption that in polygynous mammals male offspring receive more resources and that they are more valuable for their mothers (Koskela et al. in review).
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