Daniel Hanley (CC BY 4.0)
UK and US researchers have developed a new camera system that produces videos replicating the colours perceived by different animals in natural settings with high accuracy.
Each animal perceives the world differently, thanks to the capabilities of the photoreceptors in their eyes. For instance, honeybees and some birds can see ultraviolet light, which is too high frequency to be perceptible by humans. Others can detect infrared light or polarised light.
Reconstructing the colours that animals see can help scientists understand how they communicate and navigate their environment. False colour images make it possible to see as animals do, but traditional techniques have serious limitations – for instance, they are unable to quantify perceived colours of animals in motion or identify certain textures (iridescent, glossy, translucent or luminescent).
In order to address these limitations, researchers from the University of Sussex, UK, and George Mason University, Virginia, US, developed a novel camera and software system capable of capturing animal-view videos of moving objects under natural lighting conditions.
“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 – for example, detecting food items or evaluating a potential mate’s display,” said biologist Professor Daniel Hanley, of the Hanley Color Lab at George Mason University. “Here, we introduce hardware and software tools for ecologists and filmmakers that can capture and display animal-perceived colours in motion.”
The system is built from commercially available cameras and housed in a modular 3D-printed casing. The camera simultaneously records video in four colour channels: red, blue, green and ultraviolet. This data can be processed into ‘perceptual units’ to generate a video of how these colours are perceived by animals based on knowledge of their photoreceptors. It can be used for honeybees and ultraviolet-sensitive birds, and in theory is adaptable for any other organism – as long as data exists on their photoreceptor sensitivities, and its sensitivities overlap with those of the camera.
The researchers tested it against a traditional method that uses spectrophotometry – a method that uses object-reflected light to estimate the responses of an animal’s photoreceptors – and found that their system predicted perceived colours with an accuracy of over 92%.
They hope that the camera system will open up new avenues of research, as well as allow filmmakers to produce accurate depictions of how animals view the world.
A paper describing the work has been published in PLOS Biology.
