Whale mums talk quietly to their calves so predators can't hear
Right whales tend to call noisily to communicate with their friends, but mother whales have a different repertoire of calls when their young are at an age vulnerable to predators like orcas and sharks. Studying right whales in the in North Atlantic, the researchers found that, when compared to juvenile and pregnant whales, mother-calf pairs made fewer loud, long-distance communication calls and more very quiet sounds. The authors expect this tactic makes it harder for eavesdropping predators to detect their presence.
Journal/conference: Biology Letters
Organisation/s: Syracuse University
Funder: Woods Hole Oceanographic Institution and the National Oceanic and Atmospheric Administration (NOAA); NOAA Southeast Science Center, OceanWorks Group, New England Aquarium, Georgia Department of Natural Resources, Florida Fish and Wildlife Conservation Commission.
The Royal Society
Acoustic crypsis in communication by North Atlantic right whale mother-calf pairs on the calving grounds
Mammals with dependent young often hide to avoid detection by potential predators. Right whale calves are vulnerable to predation and therefore mothers might attempt to hide to avoid detection. Right whales communicate with loud acoustic signals, which can travel over long-distances. One way to ‘hide’ would be to call more quietly or stop calling completely. Our results show that right whale mother calf pairs reduced the number of louder, long-distance communication signals they produced when compared to juvenile and pregnant whales and increase the proportion of very quiet sounds that they produce. This behaviour would minimize the risk of eavesdropping by predators.
The Royal Society