On film: a blue whale's banquet
Rare new footage captured off the Californian coast could be prove vital for research into the lives of the largest animals on the planet.
Blue whales are the heaviest animals on Earth, reaching up to 180 tonnes.
And when you're that big, every meal matters.
A blue whale's main food source is provided by swarms of tiny crustaceans called krill. It can engulf millions of these in every mouthful.
All those krill make a blue whale's dinner the biggest banquet in the natural world, with no other animal able to eat so much in one go.
But opening such a huge mouth takes enormous effort, and scientists are still working to understand exactly how the whales make the exertion worth it.
New footage could help experts learn more about the meals of these ocean giants.
A rare view
Wildlife photographer Slater Moore captured this drone footage off the coast of California in June.
Slater was on a Discovery Whale Watch boat when he got the footage.
He said, 'This is by far the coolest thing I have ever filmed from the drone.'
Researchers often use drones to study marine mammals like blue whales, but feeding footage like this is rarely captured.
Richard Sabin, Principal Curator of Mammals at the Museum, says, 'Filming blue whales in their natural habitat is difficult because these animals are so elusive. This is amazing footage.
'Aerial footage taken by drones of blue whales feeding is very rare, and incredibly useful to scientists.
'Drone footage from above is commonly used by researchers, but not much of it captures the feeding event.'
A great lunge forward
Blue whales feed by lunging forward toward krill swarms, turning on their sides as they open their mouths.
Scientists are studying exactly how the whales approach and select the swarms of krill they eat.
Research lead by Oregon State University's Maine Mammal Institute analysed the lunging behaviour and found that blue whales swim towards the krill at about 10.8 kilometres per hour.
And the act of opening their mouths to capture the food slowed them down to about 1.8 miles per hour.
After quickly slowing down to eat, speeding up again takes substantial energy when you weigh 180 tonnes.
It means that blue whales only make the effort to eat when they are sure the krill patch is large enough. They bypass swarms that are too small, that would slow them down unnecessarily.
Scientists have only recently been able to study the lunge-feeding behaviour, thanks to advancements in technology.
Richard explains, 'Footage of the mechanics of feeding behaviour is of particular importance to researchers, highlighting the assessment and preparation that blue whales make before they commit energy to engulf their prey.
'More and more data are being generated from field studies of blue whales using drones and tags, giving us an increasing understanding of their lives.
'The study of museum research collections provides invaluable data in areas such as population structure, long-term feeding habits, health and reproduction - but researchers need to study the living species to help fully understand the whole organism, its behaviour and its ecological role.'
In the Museum
Our new knowledge of this feeding behaviour is marked by the Museum's redisplay of its blue whale skeleton.
The specimen hangs in a diving position in Hintze Hall. Walking underneath the diving whale allows visitors to get a sense of the movement of the huge creature for the first time.
Using research data collected from field studies, Richard advised the team on exactly how the whale should hang: as if it is lunging through the space, about to feed.
He says, 'Through the design of our blue whale's diving, lunge-feeding posture, I wanted to illustrate our growing understanding of this animal's complex, highly dynamic feeding behaviour.'