The whale newborns might be incapable of making louder sounds, due to their smaller body size and inexperience in vocalizing, but many infants throughout the animal kingdom can make a noisy racket.
If the mothers and calves are intentionally lowering the strength of their vocalizations, that would suggest an extraordinary level of not only self-awareness, but also awareness of what others in the region could be capable of hearing. These skills could indicate a very high level of intelligence.
It has long been documented that loud man-made sounds, such as those produced by ships and military exercises, impact whales and other marine life. The determination that humpback whales whisper suggests that human-produced machinery sounds could be particularly harmful to calves and their mothers.
“Ship noise travels far in water, and thereby masks the quiet calls between mother and calf,” Videsen explained. “In masking the calls between mother and calf, ship noise could result in a separation between mother and calf, making the calf more susceptible to potential predators.”
“Accordingly,” she noted, “we recommend that such effects are considered when mitigating human activities on nursing grounds.”
WATCH: Do Whales Communicate in Different Accents?