Fish hats, secret pockets, rock massages and other amazing marine mammal details

Fish hats? On whales? Sometimes in doing research for an article, I come across an odd story on social media. It’s strange enough that I feel compelled to dig deeper trying to find out if it’s an Internet legend or fact based. That was the case with a story I read about orca whales. A story stated that some orca’s in the waters near Seattle had adopted the fashion trend of wearing fish on their heads. Knowing a bit about orca aka killer whales in the wild, I had a healthy suspicion that this story was just that – a story.   

Fish hats  

What I found was a note in an academic article about an orca swimming around with a fish on its head. No photograph accompanied the observation. THEN, just this year, a photograph appeared of an orca swimming with a fish on its head! A story by Matt Baume included photographic evidence taken by Oceanwise. Baume reported that this photo (above) was taken by Gary Sutton in 2018 using a drone. The photograph was part of a study Oceanwise is conducting on the southern population of orca whales. They are looking at the whales’ response to fluctuations in the availability of salmon and other prey. According to Oceanwise, the fish-balancing act wasn’t play behavior or learning. While the behavior is now captured in a photograph, the reason why orca do is as yet not understood. Because documentation of the behavior spans a period from 2004 to 2018, it seems well established that some killer whales select to wear fish on their heads.

Secret pockets 

The engaging antics of the California sea otter are well known because these small marine mammals are easy to watch from shore. Otters live in kelp beds along the coast of Central California.  My earlier post titled More than cute and furry sea otters are ocean stewards and deserve protection reports that the fur trade was a nearly catastrophic chapter in the history of sea otter survival. Their numbers were severely reduced in the 1700 and 1800s by hunters who sought the sea otter’s highly prized fur. Otters have the densest fur of all mammals with up to one million hairs per square inch. This dense fur traps air which acts as an insulator for the otter protecting it from the cold Pacific Ocean. Unlike whales, seals sea lions, and walruses, sea otters don’t have a thick layer of blubber to insulate them. Their dense fur also helps to conceal the otter’s secret storage compartment. Otters have loose folds of skin under their forearms. These function as pockets in which the animals tuck away tasty tidbits and their favorite rocks. Click here to see a video. The rocks come in handy and are used as chopping blocks when the otter wants to dine on shellfish. The rock is placed on the otter’s chest and with the shellfish in held between their paws, they smash the shell against the rock. Click here to see video of an otter pounding a clam. Anyone watching otters eating shellfish are acquainted with the sound of the otter cracking shells.

Bubble nets

Some whales like the Pacific spotted dolphin blow tiny bubbles. The behemoth humpback whale blows much larger bubbles from their blowholes, an opening at the top of a whale’s head used for breathing air. The bubbles are referred to as bubble nets because they are a strategy used by whales to capture fish. A group of  whales dive below a school of fish before they blow bubbles. The bubbles surround the fish like a seine net. As the whales ascend they capture the fish in their gaping mouths. At the surface, the whales enormous tongue pushes the water through baleen, keratin plates located inside the whale’s mouths. The plates function like a strainer. Water moves outward while the fish are trapped inside the mouth and then swallowed.

Dr. David Wiley has been credited with leading research to study the bubble net feeding strategy used by humpback whales. He noted that humpbacks work in teams of at least two individuals to create the bubble-nets. Click here to see a video. From 2016 to 2018, other researchers documented that some humpback whales use their pectoral flippers to reinforce weak areas of the bubble barrier and possibly disorient the fish. The flipper action makes the humpback’s feeding behavior more successful.

Rock Massage

Whales occasionally enjoy a good body rub particularly if they live a long time, maybe upwards of 200 years. That’s a lot of dead skin that can accumulate without some exfoliation. Sarah Fortune has studied Arctic bowhead whales in Canada’s Cumberland Sound. There she discovered that whales molt or shed their outer, old layers of skin during the warmer, summer months. Skin shedding is a common occurrence in whales and Fortune, as her name implies, had the luck of documenting the exfoliation behavior. Click here for a video.

It is thought that exfoliating the old skin helps to remove parasites such as lice and skin that may have been damaged by the sun. Jeff Gorfeld wrote that “The latter could reduce the risk of ultraviolet radiation during the summer at high latitudes, which could be important for long-lived species by limiting age-accumulated skin.” Rock rubbing behavior also has been observed in orca. Whales swim close to shore and rub themselves on pebbled beaches. Some researchers speculate that the behavior and places chosen for body rubbing are passed between generations. “It’s probably something social, maybe a ritualistic behavior because they're very specific in the beaches that they go to," said Carla Crossman. “They seem very excited coming into these beaches -- we see them jumping up a little bit more, squealing, making lots of noise underwater."

Remarkable behaviors

These are just a few of the remarkable behaviors that have been uncovered about marine mammals. Others include marine biologist Jeremy Goldbogen discovery from video cameras placed on the backs of blue whales that Remora australis hitch unsecured rids on the whales as they swim along sometimes at high speed. And, what about beluga whales? They can change the shape of the fatty bulge at the front of their head. Often referred to as the melon, belugas rely on the fatty tissue in the melon to transmit and modify sound waves. It is an important adaptation for communication for the beluga that lives in the frigid waters of the arctic.   

Mother Nature has created so many amazing creatures, creatures that we know so little about because they live below the surface of the water. It is lucky there are curious and ingenious people who find ways to unlock the amazing details.