Evidence for echolocation in Asian shrew moles

Area of Science:

• Zoology
• Bioacoustics
• Sensory Ecology

Background:

• Echolocation is crucial for navigation in low-visibility environments.
• Nocturnal mammals, especially insectivorous moles, are hypothesized to use echolocation.
• The diversity of echolocating mammals may be underestimated.

Purpose of the Study:

• To investigate echolocation abilities in Asian shrew moles (subfamily Uropsilinae).
• To determine the mechanism and function of ultrasonic vocalizations in these moles.

Main Methods:

• Recording and analyzing ultrasonic pulses produced by Asian shrew moles.
• Conducting behavioral experiments to confirm echolocation usage.
• Examining the morphology of the stylohyal bone and performing tongue ligation experiments.

Main Results:

• Asian shrew moles produce ultrasonic pulses (50-100 kHz) resembling echolocation calls.
• Behavioral tests confirmed the use of these calls for echolocation.
• Tongue is identified as the vocalization source for echolocation.

Conclusions:

• Asian shrew moles represent a new mammalian lineage capable of echolocation.
• Echolocation has evolved independently at least six times in mammals.
• The species diversity of echolocating mammals is likely significantly underestimated.