A comparative study of rodent ultrasonic vocalizations during copulation

Area of Science:

• Animal behavior
• Bioacoustics
• Rodent reproductive biology

Background:

• Ultrasonic vocalizations (USVs) are crucial in rodent communication, particularly during social interactions.
• Understanding the temporal patterns of USVs during copulation can reveal species-specific mating strategies and communication dynamics.

Purpose of the Study:

• To investigate and compare the temporal patterning of USVs during copulation in Djungarian hamsters, prairie voles, and montane voles.
• To determine which sex produces the majority of USVs during copulation.
• To compare these findings with existing data from other muroid species.

Main Methods:

• Recording ultrasonic vocalizations (USVs) from male-female pairs of Djungarian hamsters (Phodopus campbelli), prairie voles (Microtus ochrogaster), and montane voles (Microtus montanus) during copulation.
• Analyzing the temporal patterning and frequency bands of USVs.
• Conducting anesthetization trials to identify the primary vocalizing sex.

Main Results:

• Each species utilizes a distinct primary frequency band for USVs (voles ~31 kHz, hamsters ~71 kHz).
• Djungarian hamsters show high USV rates during copulation, low rates before and after. Vole species maintain high rates throughout, decreasing post-ejaculation.
• Anesthetization trials indicate males are the primary producers of USVs during copulation.

Conclusions:

• Rodent species exhibit distinct temporal patterns and frequency usage of USVs during mating behavior.
• Male rodents are the main vocalizers during copulation, suggesting a role in courtship or signaling.
• These findings contribute to a broader comparative understanding of rodent reproductive bioacoustics.