ABS 2022
Novel Ultrasonic Vocalization Subtypes in Pair-Bonded California Mice (Peromyscus californicus)
Patrick Monari, Candice Malone, Emma Hammond, Yiru Chen, Catherine Marler. University of Wisconsin-Madison, Madison, WI, United States

California mice are one of few monogamous mammal species. Bonded females and males defend territory, acquire resources, and care for young. The ability to effectively coordinate behavior as a dyad is an important emergent property involving vocal communication. California mice produce a rich repertoire of ultrasonic vocalizations (USVs) crucial for joint territorial defense, affiliation, and offspring care. While the known functions of several USV types are materializing, conventional USV categories are broadly defined and contain substantial feature variability, suggesting the possibility of call subtypes. To uncover nuance within USV categories, we trained a convolutional neural network on California mouse USVs and identified novel USV subtypes based on tonal contour features. To investigate the functional roles of these subtypes, we administered chronic intranasal oxytocin to female and male mice prior to pairing. Machine learning revealed that oxytocin increased the frequency of transition between call subtypes during courtship and pair bond development. Our results suggest that oxytocin has long-term impacts on vocal communication and underscore the complexity of USVs.