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“The extraordinary power of flowing water makes it our planet’s greatest architect. Freshwater not only shapes the land, but life itself – it is the most precious ingredient for life on Earth. A resource for humans, and a home for countless species that simply cannot survive without it. Freshwater is the lifeblood for all planet Earth.”
Sir David Attenborough
Episode synopsis
Freshwater is the lifeblood of planet Earth, and the stage for extraordinary animal dramas.
In the heart of the Costa Rican rainforest, up to 10,000 gliding tree frogs descend from the canopy for the most important breeding event of the year. The world’s largest gathering of its kind will only last a day and, with males outnumbering females 9:1, competition is fierce.*
In Sri Lanka, as the dry season reaches its peak, the last remaining waterhole for miles around becomes a magnet for a different animal. Up to five metres long, mugger crocodiles lurk beneath the surface, waiting patiently for thirsty chital deer to approach the waterhole for a drink. Behaviour documented nowhere else, these crafty crocodiles have learned how to create traps…
Nestled amongst flowering water lilies, newly hatched ‘lily-trotter’ chicks learn a most important lesson…how to walk on water! Their oversized feet – almost double the length of their body – make for a wobbly start but their dedicated father will do whatever it takes to keep them safe during the most vulnerable stage of their life.
Water can appear, vanish, or transform rapidly, so survival in these dynamic environments can be challenging and hinges on adaptation. In the Okavango Delta, the arrival of the great annual flood poses a significant challenge for a pack of five African painted dogs who must find an innovative way to master this changeable water world.
On the remote volcanic island of Bioko, in Equatorial Guinea, millions of goby fish prepare for a perilous journey. After months feeding out at sea, they return to freshwater to breed. The safest place to lay their eggs is at the very top of a 30 metre waterfall. For a fish only an inch long, this will require a bizarre physical transformation.
In a few rare places, like Lake Malawi, freshwater has remained a consistent presence for millions of years, resulting in a dazzling diversity of life. Here over 1,000 unique fish species thrive – more than any other lake on Earth – but surviving in these crowded waters demands ingenuity.* Meet nimbochromis livingstonii, a master of deception that tricks other fish into thinking it’s dead!
Freshwater is vital to life, yet it is a finite resource. Of all the water on Earth, only 2.5% is fresh and most of that is locked up as ice or hidden deep below ground. In fact, less than 1% of freshwater is accessible.*
Humans rely on freshwater for drinking, agriculture, irrigation, industry, and power. Throughout history we have devised extraordinary means to ensure it’s available, yet today, two thirds of our world’s great rivers no longer reach the sea.* In the last 50 years, freshwater species have seen an 83% decline globally – faster than that of species in any other habitat.*
One animal suffering on the front line is the Indus river dolphin in Pakistan. This species is the most endangered freshwater dolphin globally, with only around 2,000 individuals remaining.* Every year, these dolphins get trapped in the network of irrigation canals, which form part of the vast ‘Indus Basin irrigation system’ – the largest such system on Earth.* As water levels drop due to agricultural demands, the dolphins become stranded in ever shrinking pools. Their only hope for survival depends on the efforts of a dedicated rescue team, working to return them to the river before it’s too late.
Filming locations and species
- Cenote pre-title: Yucatán Peninsula, Mexico
- Gliding tree frogs: Osa Peninsula, Costa Rica
- Mugger crocodiles hunting chital deer: Yala National Park, Sri Lanka
- African jacana: Chobe River, Namibia
- Wild dogs hunting lechwe: Okavango Delta, Botswana
- Cichlid, or ‘play dead fish’: Lake Malawi, Malawi
- Goby fish: Bioko, Equatorial Guinea
- Indus river dolphin: Sukkur region, Pakistan
In numbers…
- Number of shoots: 16
- Number of shoots managed remotely: 5
- Number of filming days: 248
- Hours spent underwater: 150
Fun fact: When filming mugger crocs hunting chital deer, our cameraman Abdullah Khan learnt to take five second micro-naps to prevent himself from missing any action. He said it kept him refreshed for the cumulative 300 + hours he spent in the hide.
Rare species documented…
The Indus river dolphin is the rarest freshwater dolphin in the world, with less than 2,000 left.*
Q&A with Producer and Director Charlotte Bostock
What was the most surprising moment when filming the episode?
It was always our ambition to use drones to film the mugger crocodiles hunting, but since it had never been attempted before, we really didn’t know if it was going to be possible! There are dozens of crocodiles hiding beneath the surface, so firstly, how do you make sure you are focusing on the right one? Not only that, but the hunt could happen at any time without warning,so how do you ensure you are filming at the exact right moment? Drones have limited battery, which in our case was around 20 minutes, so timing was critical. There were so many elements that needed to come together to make that one filming moment possible, and many of them out of our control, so when the team did eventually capture it, I think we all reviewed the clip about ten times before we could believe it!
What is your favourite moment in this episode?
My favourite moment in this episode is the stark juxtaposition between the braided river aerials – where we see freshwater flowing freely – and the shots of the dam that holds freshwater prisoner. I wanted there to be a point in the film where the audience emotionally connects with freshwater and its story. We were very deliberate about the visuals, music, soundscape and grade here to make this moment as impactful as possible.
Was there anything you wanted to capture but couldn’t?
We were very much hoping to film the removal of the Klamath Dam in America which is set to be the biggest dam removal on record,* however it has been delayed and so we unfortunately missed our filming window.
You managed to film the rescue of a rare Indus river dolphin in the vast irrigation network of Pakistan. What was it like to witness this?
Filming the rescues was challenging because once the dolphin is captured, it needs to be transported to the river as quickly and safely as possible. As the film crew, we needed to make sure we weren’t getting in the way, but that we were also getting the shots. It’s a high-pressure situation and there isn’t really much time to think. However, on one occasion I went slightly ahead of the team to get into position, and I was able to stop for just a moment. It was then that I really took in the significance of what I was seeing – the world’s rarest freshwater dolphin (of which many people have probably never heard, let alone seen) being lifted out of the river on a stretcher. It was a very surreal but powerful image that will stay with me for a very long time.
What lengths did the crew have to go to, to get the amazing footage we see in this episode?
Some of the endeavours of the freshwater team include: spending 150 hours underwater; learning how to take five second ‘micro naps’ in order to stay focused and awake during 14 hour hide shifts, plus creating a custom built nest cam that we could deploy without disturbing the jacanas – a skill which took almost a month to practise.
What do you want audiences to take away from this episode?
I want to inspire the audience to see freshwater a little differently. It is not only a habitat or a resource, it’s the lifeblood of our planet and it’s so incredibly precious.
Key stories explained
Gliding tree frog breeding frenzy
Osa Peninsula, Costa Rica
NB: filming first
At the start of the rainy season, up to 10,000 tree frogs glide down from the tree canopy to breed. It is also thought that this is the largest gathering of gliding tree frogs in the world and to the best of our knowledge this behaviour has never been filmed for a documentary before.
The mating event is usually over within a day and a ‘super explosion’, where some 10,000 frogs turn up at once, usually only happens on one occasion at the start of the season. The timing of this is difficult to predict and it took two shoots over two separate years for the film crew to be there at the right time.
Abi Brown, Assistant Producer said: “We timed our shoot with the beginning of the rainy season in Costa Rica as this is when the first, and largest, breeding event occurs. Up to 10,000 frogs can come down to a single rainforest pond to breed! There were frogs everywhere, on every leaf and every branch – and even on our filming equipment! The noise of so many frogs was deafening and we had to shout to be heard by one other. To film the spectacle, we had to stand in the pond itself – which was chest deep for me. To make matters worse, there were two caiman living in the pond – but luckily they were more interested in the frogs than in us!”
Indus river dolphin
Sukkur region, Pakistan
NB: Endangered species, filming first, new technology
Pakistan is home to the largest irrigation system in the world – a complex network of dams and canals that diverts and drains the great Indus river in order to irrigate agriculture – an area the size of England. It is also home to the world’s most endangered freshwater dolphin – the Indus river dolphin.* Each year, particularly during the dry season, they can become trapped and die in the irrigation canals. At these times, rescue missions are their only hope for survival.
For over three weeks our team worked with local camera operators, scientists and the rescue unit to tell this little known story. As rescue missions are high pressure situations where speed is key, we needed to be reactive and mobile. By working with local camera operator Adullah, and a small handheld gimbal system we were able to be ‘in on the action’. The result is an ‘obs doc’ filming style but with a cinematic look that shows the rescue in a very intimate way.
For the ‘Making of’ section, the team also had a filming first – capturing footage of the first satellite tags being put on this species. This had never been tried before because the dorsal fin of the dolphin is particularly small and so it has taken nearly 10 years to develop the correct technology. The tags were successfully deployed and returned some promising movement data. The team now hopes to tag more dolphins to better understand how they are getting trapped in the canals.
African Jacana – ‘Super Dads!’
Botswana and Namibia
NB: New technology
To get underwater and split screen shots of the African jacana the team had to construct a specialised underwater film rig. Due to the presence of hippos and crocodiles, this rig had to be remotely operated from a boat and not only that, but a boat 15m away to ensure the birds were not disturbed. This involved placing a ‘Z cam’ in an underwater housing on the end of a long pole and remotely controlling the camera through an app on an iPad. Deploying the rig took time and patience as we had to gradually introduce it to the jacanas so as not to disturb them. But the main issue was trying to manoeuvre the rig on the end of a long pole because it kept getting tangled in the lilies! It was a skill that took almost four weeks to capture usable footage!
Play dead fish
Lake Malawi
NB: New behaviour, high speed technology
The ‘play dead fish’ is an ambush predator that tricks its prey into thinking it’s dead. Its mottled colouration mimics decaying fish. It lies completely motionless on the seafloor, attracting scavenger fish who are looking for a meal.
The original scientific studies done back in the 80s captured only crude photos and real time videos, therefore the film team didn’t really know what to expect or what the behaviour actually looked like! To stand the best chance of successfully filming it the team decided they needed to spend as much time as possible underwater so they dove on rebreather units. Not only this but they filmed with a high-speed camera. This was a critical tool as the hunts are over in a blink of an eye so by filming off-speed they captured the hunt in slow motion.
This high speed camera also revealed a behaviour never documented in this species – the fish appeared ‘to hold its breath’ when the prey came close. The lead scientist on location suspects that this could be another tactic to make itself appear dead but as it has never been witnessed before it will require further scientific investigation.
Mugger crocodiles hunting chital deer
Yala National Park, Sri Lanka
NB: New behaviour
During the dry season in Yala, freshwater all but disappears and animals are forced to gather at the last remaining waterholes. Here, mugger crocodiles have been seen doing something incredible – creating traps to hunt chital deer. The crocs dig wallows right at the water’s edge and disguise themselves beneath vegetation in order to ambush their prey. A behaviour that to our knowledge, this has never been documented or filmed anywhere else in the world.
The team wanted to cover the action not only from the ground but from a drone, as it’s only from the air the strategy is very clear. This was something that had never been attempted before and the BBC crew were the first international team to be granted drone access in the park.
It took four years before the crew were finally able to capture the hunt with a drone. Unprecedented weather, political unrest plus the global pandemic made it virtually impossible year on year. In total the shoot was rescheduled over 10 times but on their final filming opportunity they managed to capture it.
Abi Brown, Assistant Producer said: “Directing the mugger crocodile sequence was one of the highlights of my career. It was an extremely challenging behaviour to film, taking us three recces and three shoots over four years to achieve. The mugger crocodiles can only hunt during the dry season as this is when the deer have no other option but to drink from their waterhole. However, whilst we were out there we witnessed what the locals called the wettest dry season they had seen in a decade, most likely due to climate change – meaning the muggers had zero chance to hunt. Finally, after many set-backs, re-organised shoots and becoming experts at predicting the weather in Sri Lanka, we managed to capture the muggers’ incredible hunting strategy. A highlight for me was watching these animals, who have a reputation for being mindless killing machines, display so much patience, skill and intelligence in order to find a meal during the tough dry season.”
Meet the team
Charlotte Bostock, Producer and Director
Charlotte, upon earning a degree in Audio Engineering, transitioned into wildlife filmmaking. A decision driven by her passion to share impactful stories about the natural world. She has worked for the BBC Natural History Unit for ten years on ‘Attenborough’ series such as ‘Planet Earth II’ and ‘Seven Worlds, One Planet’.
The greatest privilege of her career has been filming some of the planet’s most endangered animals, such as the last two remaining Northern white rhinos, the Iberian Lynx and for Planet Earth III – the Indus River Dolphin. She is incredibly fortunate to meet and work with inspiring people around the world, who devote their life to protecting the natural world and hopes that this series will highlight the challenges it faces.
Abi Brown, Assistant Producer
Abi Brown is an Assistant Producer for the Freshwater and Heroes episodes of Planet Earth III. Growing up she fell in love with wildlife, conservation and photography and felt a career in wildlife film-making would bring all three passions together. After directing and shooting her own independent films abroad, she has since spent seven years working at the BBC Natural History Unit, the past four on Planet Earth III. During this series Abi was responsible for directing many sequences and had the privilege of working alongside extremely talented cinematographers, local guides, scientists and conservationists. She witnessed one of the largest breeding events of gliding tree frogs in the world in Costa Rica, captured the ingenious hunting strategy of mugger crocodiles in Sri Lanka, during the incredible rescue efforts to save black rhino in South Africa and witnessed the undercover arrest of elephant ivory traders in Côte d’Ivoire.
Nick Easton, Producer and Director
Nick Easton is Producer-Director for the Coasts and Freshwater episodes of Planet Earth III. Nick is passionate about inspiring audiences about the natural world with compelling stories. He joined the BBC in 2008, and over the course of his career he’s been involved in Emmy and Prix Italia winning films, he’s filmed fighting giraffes (Africa, 2013), sheep-herding drones (Wild New Zealand, 2016) and pumas hunting penguins (Big Cats, 2018). For Planet Earth III Nick oversaw nearly 30 shoots on four continents, from cave-diving in Mexico to ancient meadows in Kent, once frequented by Darwin himself. Nick features in the Making of Planet Earth III segment for Freshwater, leading a crew to film the rescue of an Indus river dolphin in Pakistan. During the course of the production, Nick also became a father twice over… it’s been a busy few years.
Abdullah Khan
Abdullah Khan is a self-taught cameraman who had been making his own films about the wildlife of his native Pakistan. Seeing his videos online, the Planet Earth III team employed Abdullah to film the river dolphin and mugger crocodile sequence, and he has since joined the Songbird initiative. This is a charity initiative set up in 2022 to develop and support aspiring natural history filmmakers across the globe. Abdullah has recently spent time in Bristol on a training course at the Natural History Unit.
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Please note all embargoes.
Planet Earth III, an 8×60’ series made by BBC Studios Natural History Unit, co-produced by BBC America, ZDF, FTV and The Open University.
Sources
*Up to 10,000 gliding tree frogs descend from the canopy, with males outnumbering females 9:1 [Source: Duellman, 1970; Savage, 2002; Ortega-Andrade, 2008]
*Over 1,000 unique fish species thrive – more than any other lake on Earth [Source: Water Wheel Volume 18, Issue 2: Volume 18 Number 2 Mar 2019 / PNAS]
* Of all the water on Earth, only 2.5% is fresh and most of that is locked up as ice or hidden deep below ground. In fact, less than 1% of freshwater is accessible [Source:US Environmental Protection Agency]
* Today, two thirds of our world’s great rivers no longer reach the sea [Source: Opperman, Jeffrey J., et al. “Sustaining the Last Rivers: The renewable revolution could keep dams off the world’s remaining free-flowing rivers.” American Scientist, vol. 107, no. 5, Sept.-Oct. 2019, pp. 302+, link accessed 15 June 2023. / Grill, G., Lehner, B., Thieme, M. et al. Mapping the world’s free-flowing rivers. Nature 569, 215–221 (2019)]
*In the last 50 years, freshwater species have seen an 83% decline globally – a faster decline than that of species in any other habitat [Source: The Rivers Trust]
*The Indus river dolphin is the most endangered freshwater dolphin globally, with only around 2,000 individuals remaining [Source: Gill T. Braulik et al, Review of status, threats, and conservation management options for the endangered Indus River blind dolphin, Biological Conservation, Volume 192, 2015 / Campbell E, Alfaro-Shigueto et al (2022) Challenges and priorities for river cetacean conservation. Endang Species Res 49:13-42. / confirmed in direct comms with Uzma Khan.]
*The Indus Basin irrigation system is the largest such system on Earth [Source: G.W.H. Simons, et al., A novel method to quantify consumed fractions and non-consumptive use of irrigation water: Application to the Indus Basin Irrigation System of Pakistan, Agricultural Water Management, Volume 236, 2020]
*The removal of the removal of the Klamath Dam in America is set to be the biggest dam removal on record [Source: NOAA Fisheries]