Female Atlantic right whales lower their voices to a whisper when communicating with their young in order to prevent "eavesdropping" by predators, researchers said Wednesday.

Several species of adult whales rarely get hunted by predators in the wild owing to their size, but preying on their young is common. 

A team of scientists used microphones attached by suction cups to look at the voice patterns of right whales - an endangered species with only around 500 known specimens remaining. 

They found that pairs of mother and calves reduced the number of loud, long-distance calls, compared to juvenile or pregnant whales. 

The maternal pairings also increased the percentage of very quiet sounds they used to communicate.

Whereas a typical right whale call could be heard from roughly a kilometer away, the modified speech would only be audible at a range of 100 meters or so. 

AFP