Does personality affect premating isolation between locally-adapted populations?

Carolin Sommer-Trembo,Jonas Jourdan,Rüdiger Riesch,Yesim Verel,Claudia Zimmer,David Bierbach,Martin Plath,Bruno Streit,Lenin Arias-Rodriguez

doi:10.1186/s12862-016-0712-2

Abstract

BackgroundOne aspect of premating isolation between diverging, locally-adapted population pairs is female mate choice for resident over alien male phenotypes. Mating preferences often show considerable individual variation, and whether or not certain individuals are more likely to contribute to population interbreeding remains to be studied. In the Poecilia mexicana-species complex different ecotypes have adapted to hydrogen sulfide (H2S)-toxic springs, and females from adjacent non-sulfidic habitats prefer resident over sulfide-adapted males. We asked if consistent individual differences in behavioral tendencies (animal personality) predict the strength and direction of the mate choice component of premating isolation in this system.ResultsWe characterized focal females for their personality and found behavioral measures of ‘novel object exploration’, ‘boldness’ and ‘activity in an unknown area’ to be highly repeatable. Furthermore, the interaction term between our measures of exploration and boldness affected focal females’ strength of preference (SOP) for the resident male phenotype in dichotomous association preference tests. High exploration tendencies were coupled with stronger SOPs for resident over alien mating partners in bold, but not shy, females. Shy and/or little explorative females had an increased likelihood of preferring the non-resident phenotype and thus, are more likely to contribute to rare population hybridization. When we offered large vs. small conspecific stimulus males instead, less explorative females showed stronger preferences for large male body size. However, this effect disappeared when the size difference between the stimulus males was small.ConclusionsOur results suggest that personality affects female mate choice in a very nuanced fashion. Hence, population differences in the distribution of personality types could be facilitating or impeding reproductive isolation between diverging populations depending on the study system and the male trait(s) upon which females base their mating decisions, respectively.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0712-2) contains supplementary material, which is available to authorized users.

Highlights

One aspect of premating isolation between diverging, locally-adapted population pairs is female mate choice for resident over alien male phenotypes
We argue that individuals with low strength of preference (SOP)-values and especially those showing a preference for alien male phenotypes are more likely to contribute to mismatched mating and potential hybridization
Animal personality (AP) could play an important role in predicting variation in SOP, and we propose the following mechanistic link: mate evaluation and mating decisions are based on both private sampling and social information use [32,33,34,35]

Summary

Introduction

One aspect of premating isolation between diverging, locally-adapted population pairs is female mate choice for resident over alien male phenotypes. In the Poecilia mexicana-species complex different ecotypes have adapted to hydrogen sulfide (H2S) -toxic springs, and females from adjacent non-sulfidic habitats prefer resident over sulfide-adapted males. We asked if consistent individual differences in behavioral tendencies (animal personality) predict the strength and direction of the mate choice component of premating isolation in this system. We asked whether variation in female preferences for resident over alien mating partners is just due to random noise or if individuals differ predictably in their strength of preference (SOP). We argue that individuals with low SOP-values (e.g., weak discrimination in favor of their own ecotype) and especially those showing a preference for alien male phenotypes are more likely to contribute to mismatched mating and potential hybridization. Most studies dealing with this topic focused on female preferences for male behavioral traits (i.e. personality traits of stimulus males) or assortative/disassortative mating based on personality traits [31], while studies on the potential impact of the choosing individuals’ personality on their preferences for mating partners from their own versus an alien ecotype have not yet been conducted

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