Budgerigar Preferences Toward Universal Auditory Cues Of High and Low Arousal – A “Better Safe than Sorry” Strategy?

Assessing others’ emotional states including arousal is crucial to survival and social interaction, with vocalizations being a particularly salient channel for conveying emotion across species. Here, we investigated whether arousal cues that are thought to be universal across vertebrates translate to perceptual preferences. Budgerigars ( Melopsittacus undulatus ) are an ideal model to study heterospecific arousal perception, exhibiting proficient spectral processing and distinct arousal-related vocalisations. We investigated budgerigar preferences using a place preference paradigm, measuring time spent with high- and low-aroused versions of synthetic sound sequences and vertebrate vocalizations. We expected a preference of low arousal over high arousal because high arousal is associated with stress. However, when testing the birds with synthetic sounds that contain universal cues to low and high arousal, our results show that while females preferred low arousal, males preferred high arousal. When we tested the birds with heterospecific vocalizations, both sexes showed equal avoidance of both conditions. Emotion recognition is thought to exploit cues shared across vertebrate species. Our results suggest that in addition to potential universal cues, the ecological niche, listener sex, and sound source type act as factors influencing emotion perception. We suggest a model for processing acoustic cues to emotion and provide testable predictions.