Universität Bern

HIGHLIGHTS

PNAS - Predation risk drives social complexity in cooperative breeders. Groenewoud, Frommen, Josi, Tanaka, Jungwirth & Taborsky
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The evolution of cooperation based on direct fitness benefits. Phil Trans theme issue compiled and edited by Taborsky M., Frommen JG & Riehl C. (2016)
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NATURE COMMUNICATIONS Kinship reduces alloparental care in cooperative cichlids where helpers pay-to-stay
Zoettl M., Heg D., Chervet N. & Taborsky M. (2013)
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Social competence: an evolutionary approach
Taborsky, B. & Oliveira, R.F.
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Larval helpers and age polyethism in ambrosia beetles
Biedermann P.H.W. & Taborsky M.
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Animal personality due to social niche specialisation
Bergmueller R. & Taborsky M.
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Environmental Change Enhances Cognitive Abilities in Fish
Kotrschal, A. & Taborsky, B.
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Extended phenotypes as signals
Franziska C. Schaedelin and Michael Taborsky
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On the Origin of Species by Natural and Sexual Selection
G. Sander van Doorn, Pim Edelaar, Franz J. Weissing
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Cambridge University Press
Alternative Reproductive Tactics: An Integrative
Approach

Oliveira R., Taborsky M. & Brockmann H.J.
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The signal value and heritability of an “extended phenotype”: crater building and multiple signalling in Lake Tanganyika cichlids


Project leader:

The evolution of courtship and exaggerated secondary sexual characters is one of the favourite puzzles in behavioural ecology. Two hypotheses are favoured to explain such traits: they may result either from a co-evolutionary arms race between a heritable trait in one sex and a heritable preference for it in the other sex (Ronald Fisher’s runaway selection process), or they may serve as a costly and hence honest indicator of the fitness of the signal bearer (‘Good genes’ hypothesis). Conspicuous secondary sexual characters and courtship behaviours are particularly prominent in lekking animals. Lek systems are very suitable to study sexual selection mechanisms because in general, the choosing sex does not obtain direct fitness benefits from its mating partners.

Our study species is the mouth-brooding Lake Tanganyika cichlid Cyathopharynx furcifer. Males of this species lek and build large sand craters to attract females. They invest enormous amounts of time and energy in the building of these mating structures. Under controlled lab conditions we manipulate male and crater qualities independently from each other and measure female preference in simultaneous, interactive choice tests. Crater qualities vary consistently between males, which may indicate heritable variation of this “extended phenotype”. We measure the heritability of this trait in long-term lab experiments.

Apart from crater building, males display also a number of other signals that apparently serve to attract potential mates, including temporary, gaudy colour patterns, elongated fins with bright tassels, and exaggerated courtship patterns. This allows us to study also the function of multiple mating signals.