Mating rates and their adaptive value in spiders of the genus Argiope
Final Report Abstract
To summarize our achievements, I can say that we completed the proposed research within the given time frame. The main task was to assess the genetic population structure of A. bruennichi in order to estimate the natural risk of inbreeding. Overall, we found a very high genetic diversity even on the scale of distances that males have to walk in order to find females and accordingly a low probability of inbreeding. We used three sampling times to be able to detect possible measures of inbreeding avoidance before and during mate search. We found a modest risk of inbreeding and no active mate choice during first encounters to avoid copulations with siblings. However, once mated females differed in their investment in mate attraction depending on whether they had sperm from a sibling or a non-sibling in their spermathecae. This strongly suggests that females facilitate multiple mating after having mated with an incompatible male. These findings support the overall hypothesis that polyandry benefits females through reducing negative effects of inbreeding. We won important insights into the trade-offs that shape mating strategies of males and females and the importance of polyandry not as a general strategy but an option to decrease the costs of unfavorable first mating.
Publications
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2014. Can male spiders detect the strength of sperm competition and risk of genital plugs when choosing between females? Behavioural Ecology
Zimmer S.M., Schneider J.M. & M.E. Herberstein
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Exploiting a moment of weakness: male spiders escape sexual cannibalism by copulating with moulting females. Scientific Reports volume 5, Article number: 16928 (2015)
Uhl G, Zimmer SM, Renner D., Schneider JMS.
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Context- and state-dependent male mate choice in a Sexually Cannibalistic Spider. Ethology, Volume 122, Issue 3, March 2016, Pages 257-266
Schneider J.M., Zimmer S.M., Gatz A., K. Sauerland
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Fine-scale spatial genetic structure suggests modest risk of inbreeding in natural populations of Argiope bruennichi. Evol Ecol Res 17: 35-51 (2016)
Zimmer S.M. & J.M. Schneider
