Acoustic crypsis in southern right whale mother-calf pairs: infrequent, low-output calls to avoid predation?
Southern right whales ( Eubalaena australis ) invest substantial amounts of energy in their calves, while facing the risk of having them predated upon by eavesdropping killer whales ( Orcinus orca ). We tested the hypothesis that southern right whale mother–calf pairs employ acoustic crypsis to redu...
| Published in: | Journal of Experimental Biology |
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| Main Authors: | , , , , |
| Format: | Text |
| Language: | English |
| Published: |
The Company of Biologists Ltd
2019
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| Subjects: | |
| Online Access: | http://jeb.biologists.org/cgi/content/short/222/13/jeb190728 https://doi.org/10.1242/jeb.190728 |
| Summary: | Southern right whales ( Eubalaena australis ) invest substantial amounts of energy in their calves, while facing the risk of having them predated upon by eavesdropping killer whales ( Orcinus orca ). We tested the hypothesis that southern right whale mother–calf pairs employ acoustic crypsis to reduce acoustic detectability by such predators. Specifically, we deployed multi-sensor DTAGs on nine lactating whales for a total of 62.9 h in a Western Australian breeding ground, and used a SoundTrap to estimate the concomitant acoustic background noise. Vocalisations were recorded at low rates of <10 calls h−1 (1 call per dive) and at low received levels between 123±8 and 134±10 dB re. 1 µPa RMS depending on call type. We conclude that such acoustic crypsis in southern right whales and other baleen whales decreases the risk of alerting potential predators and hence jeopardizing a substantial energetic investment by the mother. |
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