Filming wildife against the odds: Sea lions hunting swans

Q & A with Producer, Jo Haley and Location Director Eva Spielvogel

Wildlife is notoriously unpredictable, as the Seasonal Seas team discovered while filming an extraordinary sequence for Blue Planet III.

In the freshwater wetlands of southern Chile, South American sea lions have developed a remarkable strategy: hunting swans. The behaviour had never been filmed for broadcast before.

Producer Jo Haley and Location Director Eva Spielvogel reveal what it takes to bring this elusive hunt to the screen, from tracking shy sea lions through a vast and complex wetland to enduring weeks of relentless winter rain.

Jo Haley: I was actually meant to film this behaviour for a different project a couple of years earlier, but it wasn't possible to obtain the permits back then due to the COVID pandemic. It always stayed with me as an extraordinary story I'd missed the opportunity to film. So when Blue Planet III came along and I was covering the region including Chile, I knew this was my chance!

This time, thanks to months of dedicated work by the production team in the UK, alongside the brilliant efforts of our fixers on the ground in Chile, we were finally able to secure the permits we needed and bring this remarkable story to life.

Jo Haley: One of our biggest challenges was finding the right boat. It had to be small and nimble enough to navigate wetlands riddled with submerged trees and logs, but fast enough to follow sea lions. And our camera gimbal weighed around 40kg fully rigged, so it needed to be stable too. Our Chilean fixer spent days scouring the region for the right vessel.

The skipper was just as important. The tides and submerged obstacles make navigating the wetlands particularly challenging, and it's all too easy to get stranded. Luckily, we managed to track down Cesar Barrales, who had almost a decade of experience skippering on the wetland for local university research, and convinced him to join us for a month of filming in the rain!

Eva Spielvogel: Given how many hunts scientists and locals had witnessed in previous years, we genuinely thought this shoot was going to be fairly straight forward. I was convinced we'd film a hunt in the first week, and that our biggest challenge will be getting all the kit onto the boat and pointing the camera in the right direction.

I was humbled almost immediately. Apparently, five minutes of optimism is all it takes to jinx an entire wildlife shoot.

Eva Spielvogel: The wetland is vast and difficult to navigate, but most critically, the sea lions aren't hunting swans nearly as often as we'd hoped! The swans appear to be adapting, moving further north into areas that are harder for sea lions to reach. There also seem to be fewer sea lions than in previous years. The behaviour we've travelled so far to film is proving remarkably elusive.

The terrain itself doesn't help. Reeds obscure our view, and remnants of submerged trees rise above the surface or lurk just beneath it. Whole stretches are inaccessible, forcing us to make long detours by boat. Not ideal when you're trying to keep track of an animal that can vanish in seconds.

We can't realistically follow or film the sea lions underwater, so we try to discreetly track these fast-moving, shy animals from a small boat across roughly 50 square kilometres of wetland.

Marine mammals are always challenging to film. I've directed shoots with humpback whales, leopard seals and elephant seals, and despite their enormous size, they can be remarkably elusive. The simple reason is that most of the time, they're underwater! Imagine trying to film a lion hunting on the savannah, except you only catch a glimpse of it for a few seconds before it vanishes completely, leaving you guessing where it might reappear.

These sea lions are particularly shy. One surfaces, and our brilliant cinematographers, Hector Skevington-Postles and Louis LaBrom, quickly try to line up their shots. But before they can even get it in frame, it disappears again. Minutes later, it might reappear a hundred metres away, in a completely unpredictable direction. It's like an enormous game of whack-a-mole.

Then there's the weather. Watching the finished sequence, you'd be forgiven for thinking we had glorious weather throughout the shoot. But that's only because the cameras weren't rolling when it was pouring with rain! And it rained a lot. June is midwinter in southern Chile and Valdivia's wettest month, averaging around 320mm of rain – more than twice what Glasgow gets in December. And that's saying something!

Being Scottish, I like to think I've experienced my fair share of rain, but this is something else. We're spending eight to ten hours at a time in an exposed boat, often in relentless downpours. When the rain gets too heavy to film, sometimes all we can do is sit there for an entire day and wait.

As Billy Connolly famously said, "There's no such thing as bad weather, just the wrong clothing, so get yourself a sexy raincoat and live a little."

Well, we're certainly prepared, covered head to toe in waterproofs, although I'm not sure any of them qualify as particularly sexy. And after weeks of sitting motionless in the rain, I'm beginning to suspect Billy has never spent a winter filming sea lions in southern Chile.

Eva Spielvogel: Patience and optimism can get you a surprisingly long way! Thankfully, the rain really does give way to sunshine and rainbows.

Sometimes the clouds part for a few hours, revealing beautiful golden winter light, and the whole wetland comes alive. The sea lions emerge, and suddenly we have our window of opportunity.

Over time, we get to know them as individuals: which ones are comfortable with us following them, where and when they tend to hunt, and how the swans' behaviour shapes their strategies. By watching them every day, we can start anticipating their movements. And towards the very end of the shoot, we finally capture a hunt!

That's what I love about wildlife filmmaking. Nature seems unpredictable, but the longer you observe, the more patterns emerge. The swans, the landscape, the weather and the tides all influence the sea lions. You begin to understand how everything is connected.

Be patient, pay attention, and what first seems like random chaos slowly begins to reveal a pattern.

The sea lions and swans sequence in Blue Planet III is a perfect example of how patience, perseverance and years of dedication can pay off in wildlife filmmaking, allowing the team to capture a remarkable behaviour never before seen on television.