March 29, 2024

Why Do Pilot Whales Chase Killer Whales Near Iceland?

” Its quite unusual due to the fact that the killer whale is this leading predator,” says Anna Selbmann, a doctoral candidate at the University of Iceland who is supervised by Samarra. “Its very uncommon that theyre scared of anything– or relatively afraid.”

Interactions in between killer and pilot whales have just been clinically recorded a couple of times, and Samarra is among the very first scientists to have observed this habits in Iceland. Given that the 2015 encounter, shes seen comparable interactions around 20 times.

Selbmann says in the majority of the interactions documented around Iceland, killer whales appear to prevent pilot whales. Occasionally things will get heated and the pilot whales will go after the killer whales at high speeds, with both types porpoising out of the water.

Killer whales are among the oceans leading predators. In Iceland, pilot whales have them running frightened.
Filipa Samarra

Icelands pilot whales may be presuming that the killer whales in the area, which mostly consume herring, are a hazard, and acting to drive them away.

This post is from Hakai Magazine, an online publication about science and society in coastal communities. Read more stories like this at hakaimagazine.com.
In 2015, out on the choppy waters off southern Iceland, Samarra and her research group were eavesdropping on a group of killer whales. As the whistling grew stronger a group of pilot whales came into view, and the killer whales seemed to turn and swim away.

” One of the big questions that we have is understanding the irregularity,” states Samarra. “We dont actually understand what are the contextual aspects that drive their response being various sometimes.”

Previous research study offers up 2 possible explanations for what the researchers were seeing. One, the killer whales and pilot whales were contending for prey. To Selbmann, this is possible but not likely, since these Icelandic killer whales mainly eat herring, while pilot whales in the location are believed to mainly eat squid.

IOP/ Katarína Klementisová

But Selbmann states its possible that the pilot whales didnt understand the killer whales werent a risk. In other parts of the world, killer whales do eat smaller sized whales such as narwhals, minkes, and belugas, and are even known to chase after down bigger baleen whales. Perhaps the pilot whales are viewing them as a risk, and responding appropriately.

To get insight into what could be driving the interactions, Selbmann and Samarra are performing acoustic playback experiments. Previous research study performed in Norway showed that when scientists played the sound of killer whales to pilot whales, the pilot whales swam straight towards the sounds and swarmed the scientists boat. “Now we wish to check the reverse,” states Selbmann. “Are the killer whales avoiding the pilot whale sounds?”

Steve Ferguson, a marine mammal ecologist at the University of Manitoba who is not included with the research study, says that the sightings are unusual due to the fact that in so many other places killer whales are a leading predator, and other smaller cetaceans tend to avoid them. Currently, scientists have actually noticed other odd cases– such as how humpback whales seem to safeguard other whales versus killer whale attacks.

Even this description isnt perfect, Selbmann states, considering the killer whales arent understood to consume the smaller pilot whales. “Theyre not actually a hazard to pilot whales,” she states.

Selbmann and Samarra invested this past summer season broadcasting pilot whale recordings at killer whales equipped with tracking tags. Far theyve conducted their experiment on 4 killer whales, and while the pilot whale calls didnt instantly frighten them off, a few of the killer whales did swim away.

Associated stories from Hakai Magazine:

– Scooping Plastic Out of the Ocean is a Losing Game

– Shopping for New Species

Animals

Iceland

Oceans

Previous research study conducted in Norway showed that when scientists played the noise of killer whales to pilot whales, the pilot whales swam directly towards the noises and swarmed the researchers boat. Far theyve conducted their experiment on 4 killer whales, and while the pilot whale calls didnt instantly frighten them off, a few of the killer whales did swim away.

Even this description isnt ideal, Selbmann states, thinking about the killer whales arent known to eat the smaller sized pilot whales. In other parts of the world, killer whales do feed on smaller sized whales such as narwhals, belugas, and minkes, and are even understood to go after down larger baleen whales. Already, scientists have noticed other odd cases– such as how humpback whales appear to safeguard other whales against killer whale attacks.

Whales