Baby humpbacks whisper to their mother to avoid becoming killer whale snack
April 26, 2017
Being eaten sucks. This simple fact accounts for some pretty incredible adaptations in nature. Now, it’s been discovered that newborn humpback whales ‘whisper’ to their mothers so they don’t become a meal for killer whales.
Scientists from Denmark and Australia overheard these quiet conversations when they tagged humpback mothers and their calves in Exmouth Gulf off Western Australia.
The study sought to understand the early life of humpback whales, which lead author Simone Videsen of Aarhus University says “we know next to nothing about”.
Humpbacks migrate 5000 miles across open water, staying in the Antarctic or Artic during winter then traveling to the tropics to breed.
A mother and calf pair swim in the Exmouth Gulf. Photo by Fredrik Christiansen.
"This migration is very demanding for young calves. They travel 5,000 miles across open water in rough seas and with strong winds,” Videsen explains. “Knowing more about their suckling will help us understand what could disrupt this critical behaviour, so we can target conservation efforts more effectively."
Videsen and her team tagged eight calves and two mothers. The tags attach via suction cups then drop off after 48 hours and float to the surface for collection. They record every sound made and heard by the whales.
In contrast to the hauntingly beautiful songs of adult humpbacks that echo through the oceans, infants use low-volume grunts and squeaks to communicate with their mothers. The calves made these quite calls when they were swimming through the murky waters of Exmouth Gulf, suggesting to the researchers that it is a way to keep their mother close by.
Videsen isn’t certain but believes the calves low-calls are an attempt to avoid detection by killer whales, which prey upon humpbacks around the Exmouth gulf. The calls could also be to avoid bringing unwanted male attention upon their nursing mothers, she continues.
"We also heard a lot of rubbing sounds, like two balloons being rubbed together, which we think was the calf nudging its mother when it wants to nurse," Videsen adds.
It’s hoped that this new information can be used to preserve this humpback nursing area: "From our research, we have learned that mother-calf pairs are likely to be sensitive to increases in ship noise. Because mother and calf communicate in whispers, shipping noise could easily mask these quiet calls."
This is yet another example of the yawning gaps that exist in our knowledge of the natural world, a world that is in danger of vanishing before our eyes if we don't protect it. Because sure being eaten sucks, but being driven to extinction by a sentient being with the ability to change the course of history, well, I'm sure that sucks a whole lot more.