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Correlated evolution between hearing sensitivity and social calls in bats.
Kirsten M Bohn1, Cynthia F Moss, Gerald S Wilkinson
1Department of Biology, University of Maryland, College Park, MD 20742, USA. kbohn@mail.utexas.edu
Biology Letters
|December 7, 2006
Summary
Bats possess exceptional hearing for echolocation and detecting prey. This study reveals that their low-frequency hearing evolved alongside pup isolation calls, crucial for mother-young recognition in large colonies.
Area of Science:
- Bioacoustics
- Animal Communication
- Evolutionary Biology
Background:
- Echolocating bats have specialized hearing, sensitive to ultrasonic frequencies for echolocation calls.
- Audible range hearing is often linked to prey detection, but the function of low-frequency hearing is less understood.
- Bat pups produce isolation calls with low-frequency elements essential for mother-pup reunions.
Purpose of the Study:
- To investigate the evolutionary correlations of low-frequency hearing in bats.
- To determine if low-frequency hearing relates to body size, high-frequency hearing sensitivity, or pup isolation call frequencies.
Main Methods:
- Analysis of published audiogram data from various bat species.
- Statistical examination of relationships between low-frequency hearing, body size, high-frequency hearing, and isolation call characteristics.
Main Results:
- Low-frequency hearing sensitivity in bats is not correlated with body size.
- A significant relationship exists between low-frequency and high-frequency hearing sensitivities.
- After accounting for high-frequency hearing, low-frequency hearing shows correlated evolution with pup isolation call frequency.
Conclusions:
- Enhanced low-frequency hearing in bats appears to have evolved to better detect and discriminate pup isolation calls.
- This adaptation is critical for effective parental investment, especially given bats' low reproductive rates and the need to identify pups in large groups.
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