Right whale moms "whisper" to their calves to steer clear of predators

New right whale mors living in rth Atlantic Ocean tone down ir underwater vocalizations, and "whisper" to ir young calves to avoid attracting predators, according to a study.

researchers, including those from Duke University in US, said  critically endangered whales h few natural predators, but calves were vulnerable to orcas and sharks. study, published in journal Current Biology, ted that new whale moms, when communicating with ir calves, drastically reduced ir "up call" which y typically used to eng with or right whales over long distances. 

New study finds Right Whales "whisper" to ir calves to avoid attracting predators 

researchers said that up call typically consisted of a short, loud nearly 2-minute long "whoop" sound that rose sharply and traveled long distances underwater. However, y ded that same call was modified while communicating with ir young ones into a very quiet, short, grunt-like sound that is audible only over smaller distances. 

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sounds were previously unkwn to scientists, and "can be thought of almost like a human whisper," said Susan Parks, le author of study from Syracuse University in US.

Parks said that variant of call allowed mor to stay in touch with calf without vertising ir presence to potential predators in area. To make this observation, researchers attached small, ninvasive recording tags via suction cups onto rth Atlantic right whales in calving grounds off coasts of Florida and Georgia in US.  researchers also attached tags to juvenile and pregnant whales found in area, and to mor-calf pairs.

" mors significantly reduced number of higher-amplitude, long-distance communication signals y produced compared to juvenile and pregnant whales," said Douglas wacek, co-author of study from Duke University. 

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wacek ded that right whale mor-calf pairs relied on acoustic crypsis a of behaviour meant to avoid detection to reduce risk of eavesdropping by predators lurking in nearby waters.

"Right whales face a number of challenges, including a very low number of calves born in recent years, combined with a number of deaths of reproductive females by collisions with large ships or entanglement in fishing gear," Parks said. 

According to researchers, only about 420 rth Atlantic right whales exist in wild today, with 30 confirmed deaths in past three years, making any ditional death a huge blow to species' chances of survival. Parks said that many behavioural traits of right whales are still unkwn, and ded that more studies on front would improve conservation efforts.

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