Cameraman Spends Three Weeks Living in a Tree to Film Millions of Bats

A cameraman lived up a tree for three weeks to film millions of bats migrating — in a spectacle that is considered to be the largest mammal migration on Earth.

For the BBC documentary Mammals, wildlife cameraman Josh Aitchison traveled to Kasanka National Park, Zambia, and lived in a tree to film the migration of 10 million African straw-colored fruit bats.

As a result of this incredible feat, Aitchison captured footage that offers a rare glimpse and unique angle into the fruit bats’ annual gathering from across equatorial Africa.

Filming The Largest Mammal Migration on Earth

Between October and December every year, as many as 10 million straw-colored fruit bats converge on an evergreen swamp forest in Zambia’s Kasanka National Park.

Flying from all over Africa, the bats travel thousands of miles to this freshwater habitat filled with fruits, berries, and flowers.

According to IFL Science, the annual event is believed to be the largest mammal migration in the world.

“Some of them have come 1,000 kilometers [621 miles] to be here just for a few weeks,” Aitchison says in a video about the making of Mammals, which is narrated by Sir Attenborough.

“When they leave, there’s this extraordinary spectacle [that is] really on a different level to any other view of mammals you will ever get.

“There are millions of bats in the air at the same time, it’s just amazing.

“One of the most extraordinary things about it is [that] they’re really noisy when they’re in the roost here and then when they leave, they go completely silent and you can’t even hear their wings.

“The sky is darkening with bats but you can’t hear them.”

‘It’s Lovely Being Up Trees’

In the video posted by the BBC, British cameraman Aitchison says that he enjoyed making the tree his home for three weeks and being able to witness the migration of millions of bats from such an unprecedented angle.

“It’s just amazing. It’s lovely being up trees because you get such a special view,” Aitchison says.

“You get this sort of privileged view out across what’s just an extraordinary spectacle. Very nearly the whole world population is in this one small area.”

The filmmaker says that no one quite knows why the entire world population of straw-colored fruit bats converge in this area — but the mystery makes the natural phenomenon more fascinating.

“No one’s really quite sure why they come so far, why they all come here, why this exact place. Partly to do with the type of trees, partly to do with the coolness in this forest,” Aitchison says.

“It’s got water underneath. It’s a swamp really. Partly there must be a massive amount of food, partly they’ve got their own social reasons to do it.

“It’s kind of lovely that we don’t know, I think. Actually I quite like it. It’s a bit of an unknown thing about nature, which is slowly giving up its secrets, and that’s one of the ones that we haven’t quite fathomed yet.”