In this next installment of our “Marine Mammal Highlights” series, PacMam’s Research Assistant Kat describing why she loves the Beluga. Don’t forget, you can watch these “Marine Mammal Highlights” discussions on YouTube or listen on our brand new podcast “PacMam Podcast“, available wherever you like to listen!
Belugas, arguably of the most enigmatic and intriguing marine mammals in the world. These uniquely identifiable cetaceans are found in the Arctic Ocean and parts of the sub-Arctic sea, where their striking white coloration makes much more sense for hiding among ice floes and camouflaging themselves from predators such as killer whales and polar bears. Belugas belong to the same family as Narwhals (see our last blog post for more on those guys!): Monodontidae. Their Latin name, Delphinapterus leucas comes from the Greek and literally means “white dolphin without fin”. Their common name, beluga, comes from the Russian “beloye” or “bielo” which means “white”. They are actually one of the smallest whales, reaching 13-20m in length and weighing up to 1.5 tons (that’s about two thirds the weight of a school bus), and females are up to 25% bigger than the males.
Their unique white coloring starts out as a creamy-grey when belugas are born, which then darkens to a grey or greyish-blue. Their skin will gradually fade to white as they approach sexual maturity which, like humans, can occur over a range of ages rather than a specific year. For males sexual maturity is typically reached between 5 and 10 years old, for females it’s between 7 and 14 years old. Belugas can live up to 50 years although typical lifespan is closer to 35-40 years.
As one might expect in an Arctic species, belugas have a thick layer of blubber covering their bodies and this makes up 40% of their body weight. This thick fat layer (up to 15cm/3in thick) helps them maintain their body temperature in the icy waters of their environment and provides a store of fat reserves that can sustain them in times of food shortages. Speaking of food, you might be asking what these unusual-looking creatures eat way up there in the Arctic? They mostly consume forage fish such as herring and capelin, but they will also eat salmon, crustaceans, and worms. Although belugas can have up to 40 teeth they rarely use them to catch or chew prey, instead preferring to suck them in like a hose! Belugas themselves are prey for orcas, polar bears and humans, as some indigenous populations still hunt these whales in the Arctic region for food, blubber and other materials.
Aside from their white color and lack of dorsal fin, the other main identifying feature of belugas is their large, protruding melon. The melon of a cetacean is a fatty organ in their forehead that is used to produce and project sounds. In the case of belugas, their large melon is flexible (you can visibly see it change shape as they vocalize!) which allows them to make the vast array of different calls this species is famous for, ranging from clicks and whistles to shrieks, chirps and even mimicking of other species! This repertoire earned them the nickname “canaries of the sea” by fishermen who first encountered them; even the calves begin vocalizing within hours after birth.
They are extremely social, living in large pods that can remain stable over decades. This is unsurprising due to their fragmented habitat and vast ranges, which would make dispersal difficult. Young often return to their natal areas year after year, showing what we call “site fidelity” to a particular location. Because of their extreme environment belugas must stick to specific timing for calving, migrations and molting to avoid getting trapped by encroaching ice.
The fact that they molt is extremely unusual for cetaceans. In the summer, belugas will congregate in shallow areas with smooth rocks, where they will rub themselves over the rocks like an exfoliator to help slough off dead skin cells. These locations often include estuaries or shallow, coastal waters, which are also warmer for the newly birthed calves as well as more conducive to this molting process.
Another unusual fact about belugas is that their cervical vertebrae (i.e. vertebrae in their neck) are not fused as they are in other cetaceans; this means that in shallow water they can still maneuver extremely well. Another useful trick? They can swim backwards! Although odd this ability could make the difference between life and death for some belugas, as they can often be trapped in shallow areas due to receding tides. This ability to swim backwards might just save their lives if they can reverse back out towards more open water. But make no mistake, belugas are by no means limited to shallow inshore waters: they often range as far as 1,100km offshore, even going up into the polar ice cap regions, and can perform deep dives to catch prey far below the surface.
Belugas are listed as “Near-Threatened” on the IUCN’s Red List of endangered species, although because of their lack of dispersal threat level should really be addressed in relation to each specific stock of whales. For example, in 2008 NOAA listed the Cook Inlet belugas as endangered, and their population is still in struggling. In addition to being hunted by humans, belugas are also highly polluted: toxins they are exposed to, either in the environment itself or through consuming food that has absorbed toxins (a process known as bio-accumulation) are stored in their fat, which is metabolized in periods of stress or starvation. And, of course, climate change is wreaking havoc on their Arctic environment. Warming waters and reductions in ice coverage do not bode well for the polar species, and belugas must contend with reductions in range, overheating, and changes in prey as well as more persistent predators. Polar bears that are starving due to lack of ice coverage are becoming much bolder in their attacks on beluga whales (check out this video to see this in action!), and may continue to be a threat to remaining numbers.
Well, I think you might understand now why I love belugas: they’re not only incredibly beautiful and graceful to watch, they are also physiologically unique among cetaceans with their bendy necks, backwards swimming and engaging vocalizations! I hope you have enjoyed learning about these beautiful mammals as much as I have.