Whispers of a rare and elusive whale were met, at last, by confirmation of a new species in 2019 when the Sato’s beaked whale (Berardius minimus) came onto the scene. However, the discovery was made based on carcasses as nobody had ever actually made a positive ID from a living Sato's beaked whale before. That was, until now.
The first-ever confirmed sighting of a living Sato’s beaked whale was announced in a paper published to Marine Mammal Science. Sat between Japan’s Hokkaido and Russia’s Kuril Islands, researchers observing orcas came away with a once-in-a-lifetime spot, as they saw not one but 14 of the elusive whales.
These exceptionally rare cetaceans are noodly animals. They stretch to 7 meters (23 feet) long but owing to their narrow bodies (compared to similarly long whales like orcas), were described as “spindle-shaped” by the researchers that first named the species.
Beaked whales’ shape in general is in part to blame for why they went undiscovered for so long, as unlike other whales who advertise their location by spouting water into the air, these whales don’t have a visible blow. This means it can be hard to see their smooth heads moving silently through the water, making them especially hard to spot in rough seas.
The Sato’s beaked whale is also darker than its closest relatives. Their coloration is what led Japanese whalers to give them the nickname karasu which means “crow” or “raven” as (back before the species scientifically existed) they noticed the Sato's were different from other whales in the area.
Subtle though they may be, that didn’t stop researchers off the shore of Kunashir Island in the Kurilsky Nature Reserve from identifying three pods across a period of six days. The groups contained between four and five individuals, and their identity was confirmed via a remote sampling device that combines a crossbow and a floating arrow to obtain skin samples. How very Katniss Everdeen.
While a significant and serendipitous set of observations, the whales didn’t make it easy for the researchers.
“While working with Sato's beaked whales, we noted the following features,” they wrote. “In most cases, even in a calm sea, the bodies of whales were poorly visible due to the low profile, and at a distance of more than 300–500 meters [984–1,640 feet] they were visible only when they arched during surfacing and diving.”
“When animals were lying flat on the surface, they were inconspicuous, especially in a choppy sea. Their detection was also hindered by the lack of visible blows.”
The only real giveaway, say the researchers, was the sound of the Sato’s whales’ exhalations which could only be detected when their boat was drifting with the engine off. It seems that the old cetacean observation approach of taking your boat out for a 20-minute float-and-listen is the best way of tracking down these elusive animals.
“Our observations provide the first insight into the behavior and ecology of Sato's beaked whales,” concluded the study authors. “More field research is necessary to determine the status of the species and to define current threats.”
[H/T: Hakai Magazine]