Predator-induced changes of male and female mating preferences: innate and learned components

Abstract

While many mating preferences have a genetic basis, the question remains as to whether and how learning/experience can modify individual mate choice decisions. We used wild-caught (predator-experienced) and F1 laboratory-reared (predator-naïve) invasive Western mosquitofish Gambusia affinis from China to test whether mating preferences (assessed in a first mate choice test) would change under immediate predation threat. The same individuals were tested in a second mate choice test during which 1 of 3 types of animated predators was presented: 1) a co-occurring predator, 2) a co-evolved but not currently co-occurring predator, and 3) a non-piscivorous species as control. We compared preference scores derived from both mate choice tests to separate innate from experiential effects of predation. We also asked whether predator-induced changes in mating preferences would differ between sexes or depend on the choosing individual’s personality type and/or body size. Wild-caught fish altered their mate choice decisions most when exposed to the co-occurring predator whereas laboratory-reared individuals responded most to the co-evolved predator, suggesting that both innate mechanisms and learning effects are involved. This behavior likely reduces individuals’ risk of falling victim to predation by temporarily moving away from high-quality (i.e., conspicuous) mating partners. Accordingly, effects were stronger in bolder than shyer, large- compared with small-bodied, and female compared with male focal individuals, likely because those phenotypes face an increased predation risk overall. Our study adds to the growing body of literature appreciating the complexity of the mate choice process, where an array of intrinsic and extrinsic factors interacts during decision-making.

Geographical and temporal variation of multiple paternity in invasive mosquitofish (Gambusia holbrooki, Gambusia affinis)

“…Moreover, the relatively low explanatory power of our models suggests that additional variables we did not quantify also contribute to patterns of MP. Likely candidates include additional sources of variation in sexual selection, such as predation (Kelly et al, ; Plath et al, ) or water pollution (xenestrogens: Díez‐del‐Molino et al, ), as well as several other environmental factors (see Table for a breakdown of factors known to influence MP in poeciliid fishes). However, it is also possible that slightly different climatic variables (for the geographic study, for example, averages of the actual year of collection rather than multiyear averages) would have increased predictive power in our analyses.…”

“…Moreover, the relatively low explanatory power of our models suggests that additional variables we did not quantify also contribute to patterns of MP. Likely candidates include additional sources of variation in sexual selection, such as predation (Kelly et al, 1999;Plath et al, 2019) or water pollution (xenestrogens: Díez-del-Molino et al,…”

Sight of parasitoid wasps accelerates sexual behavior and upregulates a micropeptide gene in Drosophila

“…Taken together, our results extend the effect of parasitoid wasps to another domain of Drosophila behavior: mating. The presence of predators has been found to affect sexual behaviors in other species, including courtship, mate choice, and nest-building in fish 39 – 41 , calling behavior in tree frogs 42 , and mating behavior in birds 43 . We have examined the effect of exposure to parasitoids, an enormously abundant class of organism, and above all we have studied the effect in Drosophila , a species that allows incisive analysis of its underlying molecular, cellular, and circuit basis.…”

Sight of parasitoid wasps accelerates sexual behavior and upregulates a micropeptide gene in Drosophila

“…Taken together, our results extend the effect of parasitoid wasps to another domain of Drosophila behavior: mating. The presence of predators has been found to affect sexual behaviors in other species, including courtship, mate choice, and nest-building in fish [36][37][38], calling behavior in tree frogs [39], and mating behavior in birds [40]. We have examined the effect of exposure to parasitoids, an enormously abundant class of organism, and above all we have studied the effect in Drosophila, a species that allows incisive analysis of its underlying molecular, cellular, and circuit basis.…”