Task differences confound sex differences in receiver permissiveness in túngara frogs

Area of Science:

• Animal behavior
• Sexual selection
• Bioacoustics

Background:

• In many species, both sexes respond to sexual signals, but error costs differ.
• Females typically face higher costs for misidentification, suggesting greater selectivity than males.

Purpose of the Study:

• To investigate whether selectivity differences between male and female túngara frogs are sex-specific or task-specific.
• To determine if behavioral context influences selectivity in mate choice signaling.

Main Methods:

• Comparative analysis of male vocal responses and female phonotaxis (movement toward sound) to conspecific calls.
• Quantification of selectivity based on responses to variations in advertisement calls.

Main Results:

• Male túngara frogs showed less selectivity in their vocal responses compared to female phonotactic responses.
• When males exhibited phonotaxis, their selectivity levels matched those of females.
• Males were significantly more selective when responding behaviorally (phonotaxis) than when producing vocalizations.

Conclusions:

• Apparent sex differences in selectivity arise from task differences (calling vs. approaching), not inherent sex differences.
• Behavioral plasticity, rather than fixed sex-specific traits, underlies observed selectivity patterns.
• These findings suggest re-evaluating sex differences in other systems where behavioral context may play a confounding role.