The Giant Red Leech

A huge 1m leech has been filmed for the first time swallowing a giant earthworm in the forests of Borneo Photo: BBC. It resembles a monster from a b-list horror film but deep in the forests of Borneo this giant leech really exists and is a deadly predator. The creature is so new to science that it does not yet have a taxonomic name. It is known to the tribes of Mount Kinabalu as the ‘Giant Red Leech.’ 

It was filmed for the first time by BBC filmmakers for the new series ‘Wonders of the Monsoon.’

The Giant Red Leech is one of the biggest in the world. The specimen captured on camera was around 1m long but experts believe they could grow larger.

They have grown so big that they no longer simply suck blood but now actively hunt giant blue worms and suck them down like spaghetti. The worm it is eating is a whopping 78cm

The new footage shows the leech detecting a worm’s trail and following the scent like a sniffer dog.

When it encounters its prey it quickly latches on and moves its lips up and down the iridescent blue body.

“It was either searching for an end to grab, or was working out whether it was too big to eat” said documentary director Paul Williams.

“When it found an end it started to suck. It was incredible” 

The worm tries to pull away but slowly the leeches lips inch forward until with a slurp, the worm is gone.

“The result is that we could confirm the predatory behaviour of a rarely-seen and unidentified species for the first time.” said added Williams.

Finding the species on Mount Kinabalu, the biggest mountain in Borneo, was a huge challenge and the team worked with ecologist Alim Bium to locate the leech.

“If you want to film a predator the best thing to do is to find its prey” said Williams, but it took the team several weeks of searching before an extremely heavy rainstorm eventually brought worms out in huge numbers. The red leeches were not far behind.

“By working with Alim we were able to sufficiently light the area of forest to record the predation as it unfolded” said Paul. 

“It was exciting and fascinating, as he was making his new scientific discovery, we were documenting the behaviour for the very first time”

Bium added: “Very little is known about them, we don’t know how they hunt, or even how big they grow, because no one has researched them.”

The new documentary follows wildlife and cultures from the Himalayers to Northern Australia whose lives are shaped by monsoons.

Innovative filming techniques and technology capture animal behaviour and stunning storm footage as never before.

The remarkable ways that animals adapt to survive the monsoon are revealed, from baby orang-utans, building umbrellas from forest leaves, to the beautiful and bizarre caterpillars in the tropical forests, who harness poison from the trees to defend themselves against predators.

For the first time the crew filmed an immense colony of 300,000 red flying foxes, a type of bat which lives in caves in the Northern Territories of Australia. 

They captured the life and death dives that the bats make into crocodile infested rivers to drink.

For director Nick Lyon, to get in a position to film the crocs meant getting amongst them. “The only way to film this was from a small tin boat. This meant navigating up the river in daylight, but more scarily the behaviour happened at dusk, so by the time we’d finished filming I had to remember the route back in pitch black through lots of hazards like sunken logs.

“It was only when the torches were turned on you could see how many crocs were in the river, and all eyes were trained on us.”

Night after night Mr Lyon had to lay flat in the boat to help keep it steady amongst the crocs while cameraman Warwick Sloss worked with the low light conditions. 

“The grabs can happen in a blink of an eye and there were so many times when we thought we’d got it but it was a false call” In the age old style of wildlife filming it wasn’t until the last day that the team got lucky.

“We didn’t even know that we’d filmed it when it happened, we had to play it back slowed down by 12 times to see that the crocodile had been successful.”

Series producer Paul Bradshaw said: “This is natural history set in the planet’s most glorious and dramatic theatre – the lands of the monsoon.

“It’s an incredibly rich mixture of extraordinary creatures, great and small, with some of the planet’s most colourful and ancient cultures, all bound together through the story of this rampaging weather system.”