It makes sense that blue whales — the largest animals on the planet — have huge mouths.
But even after seeing the 200-ton animals that these mouths belong to, the enormity of these fish-guzzling caverns is still shocking.
These mouths stretch far down the animals’ bodies in blubbery extensions that allow them to ingest their weight in water and fish.
“It’s equivalent to if you could shove your hand into your mouth and under the skin right down to your belly button,” Robert Shadwick, a zoologist from the University of British Colombia, told the BBC when describing how the creature feeds. “A sort of pouch under the skin, which balloons out enormously — almost into a spherical bubble.”
This process of opening their mouths takes a lot of energy — since the mouth acts as a sort of parachute. So whales have to be picky about what particular schools of krill are worth the effort.
When they’ve decided on a target, they turn on their sides, open their mouths — rapidly decreasing their speed from about 6.7 miles per hour to 1.1 miles per hour — and swallow the entire pack.
They then use the comb-like features of their mouths to filter all of the fish into their stomachs.
Though this hunting process has been understood for quite some time, researchers have never gotten a really great look at it.
But with new drone technology that allows the whales to be filmed without disturbing them — researchers at Oregon State have now captured stunning footage of the entire blue whale dining experience.
“So this is something we often see from the boat and we see splashing and we can tell the animal turns on its side,” Leigh Torres, a marine ecologist who led the team capturing the footage, says in the video. “But with the drone we were able to get this remarkable new perspective.”
The video also shows the whale ignoring a smaller school of fish, preferring to save the mouth-opening energy.
“It would be like me driving a car and braking every 100 yards, then accelerating again,” Torres said in a press release. “Whales need to be choosy about when to apply the brakes to feed on a patch of krill.”
Torres noted that this new level of understanding might help humans better protect the endangered whales.
“Lots of human activity can influence krill availability,” she told National Geographic. “We pretty much know having some krill in the water doesn’t make good habitat. There has to be krill density.”