title: Cryptic female Strawberry poison frogs experience elevated predation risk when associating with an aposematic partner.
abstract: Population divergence in sexual signals may lead to speciation through prezygotic isolation. Sexual signals can change solely due to variation in the level of natural selection acting against conspicuousness. However, directional mate choice (i.e., favoring conspicuousness) across different environments may lead to gene flow between populations, thereby delaying or even preventing the evolution of reproductive barriers and speciation. In this study, we test whether natural selection through predation upon mate-choosing females can favor corresponding changes in mate preferences. Our study system,Oophaga pumilio, is an extremely color polymorphic neotropical frog with two distinctive antipredator strategies: aposematism and crypsis. The conspicuous coloration and calling behavior of aposematic males may attract both cryptic and aposematic females, but predation may select against cryptic females choosing aposematic males. We used an experimental approach where domestic fowl were encouraged to find digitized images of cryptic frogs at different distances from aposematic partners. We found that the estimated survival time of a cryptic frog was reduced when associating with an aposematic partner. Hence, predation may act as a direct selective force on female choice, favoring evolution of color assortative mating that, in turn, may strengthen the divergence in coloration that natural selection has generated.
authors.affiliation: Animal Ecology Department of Ecology and Genetics Uppsala University Uppsala Sweden.
authors.forename: Julia Carolina
authors.initials: JC
authors.lastname: Segami Marzal
authors.affiliation: Animal Ecology Department of Ecology and Genetics Uppsala University Uppsala Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Rudh
authors.affiliation: Department of Zoology: Ecology Stockholm University Stockholm Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Rogell
authors.affiliation: Animal Ecology Department of Ecology and Genetics Uppsala University Uppsala Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Ödeen
authors.affiliation: IFM Biology Linköping University Linköping Sweden.
authors.forename: Hanne
authors.initials: H
authors.lastname: Løvlie
authors.affiliation: IFM Biology Linköping University Linköping Sweden; Faculty of Life Sciences University of Manchester Manchester UK.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Rosher
authors.affiliation: Animal Ecology Department of Ecology and Genetics Uppsala University Uppsala Sweden.
authors.forename: Anna
authors.identifier: 0000-0002-1178-4053
authors.initials: A
authors.lastname: Qvarnström
keywords: Oophaga pumilio; aposematism; assortative mating; crypsis; predation; sexual selection; speciation