Humpback whales, the crime-stoppers of the sea
A major study into humpback whales has found that they are the police of the seas, defending sea life from pods of killer whales.
In the depths of the deep blue seas, it can be a lonely, dangerous place. Unless you’re on the top of the food chain or, better still hidden from the gaze of humans, there’s very little assistance on offer.
Sure, some prey is numerous, others fast or poisonous, but the tools each individual inherited from its parents are pretty much all any creature has to defend itself.
At least, that is what many thought. However, a new study into an odd behaviour among do-gooder humpback whales may change that.
Under the sea
Led by Robert Pitman, a marine ecologist in the US, researchers found growing incidents of humpbacks intervening in killer whale attacks, with less than 10pc of the 115 examples showing humpbacks rescuing humpbacks.
This was “particularly puzzling”, according to the study.
On every other occasion, it was grey whales, sun fish, harbour seals or sea lions that felt the benefit of a giant ally – though it’s not clear how successful a rescue mission this tends to be.
The paper came about after Pitman witnessed an attack on a seal in the Antarctic back in 2009. The seal was on an ice floe, with orcas attempting to knock it off and kill it. Humpbacks intervened, with the seal escaping on one of their chests while it swam on its back away from the killer whales.
There’ll be no accusations
Following this long-term study, Pitman and his colleagues suggest that humpbacks can hear predators like killer whales and react to their hunting noises, only discovering on arrival what it is they are hunting.
This could mean they’re used to battling with orcas when rearing young calves.
Weirdly, the researchers found that many of the humpbacks engaging in rescue missions sported scars, indicating that they were survivors of orca attacks in their youth.
This could mean they’ve developed a serious dislike for orcas and are always willing to interfere with their feeding.
Examples given in the paper include one of an orca hunt on a grey whale calf that took hours. Throughout the hunt everything seemed binary and normal, until “out of nowhere” a group of humpbacks turned up and kept the peace.
However, the humpbacks are not alway successful.
Just friendly cetaceans
“Although this behaviour is very interesting, I don’t find it completely surprising that a cetacean would intervene to help a member of another species,” said Lori Marino, president of the Whale Sanctuary Project, when talking to National Geographic.
Due to humpbacks’ impressive intelligence – demonstrated through decision-making, problem-solving and general communication – it makes for a “species with a highly-developed degree of general intelligence capable of empathic responses”.
Orcas are not always subtle with their hunting. Image via Shutterstock
Under the sea
Despite the size advantage fully-matured humpbacks have over orcas – thus making any counter-attack opportunities almost impossible – this behaviour isn’t all sun and roses.
These attacks take hours and can cause the humpbacks to exert huge amounts of energy chasing down and driving away the orcas.
This has a knock-on effect, requiring the humpbacks to eat more to keep their energy reserves sufficient.
The true cost of a hero at sea? Food.
Main image of humpback whale via Shutterstock
