Xavi Bou had spent 15 years working as a photographer and teacher in the world of advertising and fashion before he embarked on the project that would consume much of the next ten years of his life. ‘One day, I was watching the tracks of an animal on a path and I thought to myself, “What kind of tracks would birds leave in the sky if that was possible?”’ he says.
He did some research and realised that no-one had attempted to visualise these paths before – at least not in the way that he had in mind. He didn’t want to use the technique often used in sports photography, in which a few different pictures of one ski jump, for example, are placed side by side to show the take off, the mid-point and the landing. For him, it wasn’t about how a bird flies, but rather the path the bird takes.
‘I feel like a curator, looking for the different choreographies that birds make in the sky,’ he says. ‘What I do is look for these different choreographies, choose a part and make it visible.’
The most common way to convey movement in a still image is to use a long exposure, ‘but in this case,’ says Bou, ‘because the sky is brighter than the bird, if you do a long exposure you erase the bird.’ Instead, he created a new technique that involves overlapping images. Rather than using a normal camera, he employs a cinematic camera to capture around 60 or 120 frames per second. He then uses a computer programme to overlap the images, a process that eventually shows the path of the birds through the sky.
For Bou, it’s all about visualising behaviour, not the birds themselves. It’s not always apparent to people viewing his images in a gallery that these are birds at all. Because of this, racking up large numbers of different species is far less important than capturing different types of movement. ‘This is something important for me,’ he says. ‘It’s not about as many species as possible, it’s more about different behaviour.’ Some birds, including starlings and swifts, demonstrate hugely complex and varied fight patterns, and Bou finds himself repeatedly returning to these animals.
Swifts might shoot across the sky erratically while hunting for insects, but at other times, they might come together as a group and fly around and around in a circle. Focusing on common birds also serves a secondary purpose. ‘Most of my work is done in Catalonia, with common birds. For me, it’s really strange that most people don’t know what a swift is. We’re talking about a bird that fills the skies – they’re everywhere. Maybe we know more about life in the Arctic or the Serengeti than in our gardens.’