2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

����92 Sabine Nöbel
Public information influences sperm transfer to females in sailfin molly males
Authors: Sabine Nöbel 1 , Klaudia Witte 1
Affiliations: 1 Section of Biology, Research Group of Ecology and Behavioral Biology,
University of Siegen
The social environment can serve as a public information network in which
individuals can gather public information about the quality of potential mates by
observing conspecifics during sexual interactions. The observing individual itself is
also a part of this information network. When recognized by the observed
conspecifics as an audience, his/her presence could influence the sexual interaction
between those individuals because the observer might be considered as a potential
mate or competitor. One of the most challenging questions in sexual selection to
date is how the use of public information in the context of mate choice is linked to
the fitness of individuals. Here, we could show that public information influences
mate choice behaviour in sailfin molly males, Poecilia latipinna, and the amount of
sperm males transferred to a female partner. In the presence of another audience
male, males spent less time with the previously preferred larger of two females and
significantly more time with the previously non-preferred smaller female. In another
experiment, males could physically interact with a female and were faced with an
audience male, three audience females or no audience. Males transferred more
sperm to a female partner in the presence of an audience male than without
audience or with female audience and spent less time courting his female partner.
Males transferred significantly more sperm to his female partner in the presence of
an audience male. Males did not transfer less sperm to their partner in the presence
of audience females than without audience. This is the first study showing that public
information use turns into fitness investment, which is the crucial factor to
understand the role of public information in the dynamic processes in sexual
selection.
����93 Maykon Passos Cristiano
Phylogeography of the leafcutting ant Acromyrmex striatus: reconstruction of the
demographic history of an open-environment associated species
Authors: Maykon Passos Cristiano, Danon Clemes Cardoso, Christoph Schubart, Tânia
Maria Fernandes-Salomão, Jürgen Heinze
Affiliations: 1 Universidade Federal de Viçosa / Universität Regensburg
The Pleistocene refugia model is the most invoked hypothesis to explain origin and
diversity of tropical forests, but it is mainly applied to fauna associated with wet and
shaded habitats. Paleo-modeling studies predict large and stable forests in north and
eastern Brazil during the last glacial maximum, but fail to predict possible stable
areas in south Brazil. Moreover, some studies did not support the Pleistocene refugia
hypothesis, and alternative models, e.g. the possible role of marine incursion and
Tertiary orogeny promoting diversification, may need to be further investigated.
Acromyrmex striatus is a leafcutter ant associated to open and arid environments
distributed throughout Southern Brazil (Santa Catarina and Rio Grande do Sul states),
Argentina, Uruguay and Paraguay. In Santa Catarina State, A. striatus occurs only
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