Humans differ greatly from the animal world in a huge number of ways, but one of the most intriguing is how they see the world. Eyesight can change vastly across species – and now we have a key insight into that difference.
Publishing their results in the journal PLOS Biology, a team of ecologists and filmmakers utilised a new camera system to produce a series of videos that accurately replicate the colours that different animals see in natural settings.
Due to the photoreceptors in their eyes, different animals perceive the world differently. Honeybees and some other birds, for example, can see UV light – an experience that is outside human perception.
By reconstructing the colours that animals actually see, scientists can better understand how they communicate, navigate the world around them, and build survival tactics.
False colour images give us a glimpse into this colourful world, but traditional methods such as spectrophotometry are often incredibly time-consuming, needing specific lighting conditions and still images.
Above: Three sulphur butterflies were filmed in colours that would be visible to other butterflies. Video credit: Daniel Hanley.
“We’ve long been fascinated by how animals see the world. Modern techniques in sensory ecology allow us to infer how static scenes might appear to an animal; however, animals often make crucial decisions on moving targets," says Daniel Hanley, an assistant professor at George Mason University and a senior author on the paper.
“Here, we introduce hardware and software tools for ecologists and filmmakers that can capture and display animal-perceived colours in motion.”
This camera can record simultaneously in four colour channels: blue, green, red and UV. This data can then be processed into what the researchers deemed 'perceptual units'.
This comes together to create an accurate video of how colours are perceived by animals, based on existing knowledge of the photoreceptors in their eyes.
Above: A northern mockingbird seen in ‘avian vision’. This is close to how these mockingbirds will see the world, with the sky appearing mainly as magenta. Video credit: Daniel Hanley.
When the team tested the system against existing technology that utilised spectrophotometry, they found the new system perceived colours with an accuracy of over 92 per cent.
The system is built using commercially available cameras, housed in a modular, 3D-printed casing, and the software is available open-source. This means researchers and photographers can use the technology for themselves.
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