Weirdest Whales: Curious Creatures of the Cetacean Nation

March 30, 2020

Whales are weird, and cool! Cetaceans (whales, dolphins, and porpoises) are found all around the Earth’s oceans, in all shapes and sizes. Here’s a few examples of some particularly unique cetaceans, and what makes them special.

 

Grey Whale (Eschrichtius robustus)

The grey whale is a strange member of the baleen whale family. Baleen whales are any whale that does not have teeth. Instead, they have long plates of keratin (think hair and fingernails) known as baleen plates. Any whale in this group will rely on filter-feeding. Baleen whales take big gulps of seawater filled with fish and zooplankton, but instead of swallowing it all, they push the water out through the baleen plates and keep only the food.

This feeding method is normal for every baleen whale except the grey whale. The grey whale is the only bottom-feeding whale. Rather than filtering its food from the water column, it stays in shallow waters and takes bites out of the ocean floor. It pushes the sandy sediment through its baleen and swallow the critters that were buried in the sand.

Greys are also known for their strange vocalizations. Rather than the beautiful songs of a humpback or the whistles of an orca, the grey whale is mainly known for “grunts”, “bongs” and “gurgles”. Their vocalizations have been likened to the sound of knocking on a metal pipe.

On top of strange food choices and unique communication styles, grey whales are known to carry heavy parasite loads of barnacles and sea lice. In fact, there are some parasites that are endemic to grey whales – meaning they are only found on grey whale bodies! The only way these parasites grow their populations is by jumping from whale to whale.

 

Bowhead Whale (Balaena mysticetus)

The bowhead whale is an Arctic whale, and it is the only true Arctic baleen whale. Bowheads have no dorsal fin – not even a hump. This allows them to break up through the sea ice to breathe without worrying about injuring a fin on their back, while also preventing extra heat loss through an unnecessary appendage.

Photo: ©Paul Nicklen/National Geographic Creative

Bowheads are a very slow growing and slow maturing species, only reaching sexual maturity at 20-25 years. This late maturity goes hand-in-hand with their lengthy life spans. Bowheads are thought to be the longest living mammal on Earth! One individual harvested in 2007 was found with stone and ivory weapon fragments that were likely manufactured between 1897 and 1885, leading scientists to believe it was between 115 and 130 years old. The current oldest age estimate for a bowhead whale is 211 years!

 

Amazon River Dolphin (Inia geoffrensis)

The Amazon river dolphin, also known as the the boto, is a true whale weirdo. This dolphin spends half the year swimming through the Amazon rainforest, which floods in the spring. The most noticeably strange trait of the botos is their pink colouration. Males are a much brighter pink which supposedly attracts females during mating season. Male river dolphins have also been seen courting females by beating the surface of the water with grasses in their mouths.

Photo ©Ivan Sgualdini / Fotolia

The boto has an abnormally long rostrum (the pointy part of their face), which it uses in conjunction with echolocation to find prey in the muddy river waters. Finally, river dolphins have unfused neck vertebrae – an adaptation for swimming through tangled branches by bending their body up to a 90-degree angle! This ability is especially important for females who are often found swimming further up-river, likely to avoid the overly-excited pink males downstream doing strange grass-based percussion.

 

Sources

https://www.nationalgeographic.com/animals/mammals/a/amazon-river-dolphin/

https://arctickingdom.com/10-fun-facts-about-bowhead-whales/

https://www.thecanadianencyclopedia.ca/en/article/bowhead-whale

https://www.fisheries.noaa.gov/species/bowhead-whale

https://www.thoughtco.com/bowhead-whale-2291516

https://www.sanignaciograywhales.org/project/acoustics/

Seim, I., Ma, S., Zhou, X., Gerashchenko, M. V., Lee, S., Suydam, R., George, J. C., Bickham, J. W., Gladyshev, V.N. (2014). The transcriptome of the bowhead whale Balaena mysticetus reveals adaptations of the longest-lived mammal.

George, J. C., Bockstoce, J. R. (2008). Two historical weapon fragments as an aid to estimating the longevity and movements of bowhead whales.

 

Written By: Lili Wilson