Female gray tree frogs can struggle to choose a mate when presented with too many options, according to new research that links choice overload to mating decisions in the wild. The study, published in iScience, suggests cognitive limits in female gray tree frogs may shift which males ultimately breed.
Indecision on the frog dating scene
Gray tree frogs inhabit wooded areas near water across North America. In breeding season, males assemble in choruses and broadcast calls to attract females. Females assess several call features, including duration. Longer calls are typically more appealing.
Researchers captured 60 female frogs from breeding choruses in East Tennessee and tested them in a laboratory setting. Each female heard a series of recorded calls and was asked to choose between one longer, attractive target call and either one, three, or seven shorter, less attractive distractor calls. Calls were played sequentially so they did not overlap.
Females indicated their preference by hopping toward the speaker broadcasting the chosen call. As the number of distractor calls increased, females were less likely to pick the attractive call, took more time to decide, and more often failed to choose within a 10-minute period.
Cognitive confusion
Because the experiment eliminated any overlap in calls, the authors conclude the effect was not due to energetic masking, which occurs when simultaneous signals make it difficult to detect or discriminate a target call. Instead, the findings point to cognitive constraints. With more alternatives to weigh, female gray tree frogs found it harder to identify and select their preferred option, even though each call was presented clearly.
When females can’t make the optimal choice
In gray tree frogs, call characteristics are linked to offspring fitness. If females struggle to recognize preferred calls in natural choruses, they may pair with males they would otherwise reject, potentially passing along less favorable traits to their young.
The study also raises a strategic possibility for males. Less attractive males might fare better in larger choruses, where numerous competitors increase decision difficulty for females. By contrast, more attractive males could benefit from calling in smaller groups or alone. The researchers plan to explore these dynamics further.
More options, more opportunities … to a point
The team used a simplified test arena to isolate the impact of choice overload, removing environmental complexity such as overlapping calls, vegetation, and predator risk. Female choice was limited to eight calls, although wild choruses can feature dozens or hundreds of males.
Next steps include evaluating how strongly choice overload operates in natural settings, where both sensory and cognitive processes are at play. The researchers are particularly interested in whether, in real choruses, females take longer to decide and more often mate with less preferred males.
Similar decision costs with increasing options have been observed across species and contexts, including bees selecting flowers, ants evaluating nest sites, and mosquitoes choosing egg-laying locations. Recent work on field crickets and other tree frogs has reported comparable patterns in call-based mate choice. Together, these findings indicate that cognitive limits are a common feature of animal decision-making.