How female treefrogs weigh unimodal and multimodal sexual displays in the absence and presence of noise

Mate choice plays a pivotal role in wildlife reproduction and population sustainability. The assessment of sexual displays in noise poses a common challenge for wildlife. Multimodal signals are hypothesized to be favored since they improve the accuracy of signal detection and discrimination in noise. We verified whether female treefrogs exhibit a heightened reliance on visual cues when acoustic cues are drowned out by the noise and whether increased call complexity can compensate for the attractiveness differences between unimodal and multimodal signals. Our results demonstrated that female treefrogs prefer longer courtship signals in the absence of noise. Meanwhile, increasing call complexity effectively mitigated the attractiveness difference between acoustic and visual/multimodal signals. However, female treefrogs did not shift their reliance to visual signals when masked by noise. Noise prolonged the duration required for females to make a mate choice in most cases and reduced female preferences for attractive signals regardless of whether the mating scene was unimodal or multimodal, which lends further the hypothesis of cross-sensory interference. We examined how female treefrogs weigh unimodal and multimodal courtship cues in the absence and presence of noise and offered distinct perspectives on the interplay of multi-sensory sexual displays in noise. This study enhanced our comprehension of noise interference in mating choice and established a novel, comprehensive scientific foundation for the prevention and control of multimodal sensory pollution.