20 October 2010
Scientists have finally discovered the truth behind Rudyard Kipling’s famous Just-So story, ‘Why the leopard got his spots’. The research, published in Proceedings of the Royal Society B, looks at whether there is any connection between the patterns on big cats’ coats and their habitat and lifestyle.
The team of researchers, led by William Allen of the University of Bristol, gathered high-quality images of more than 30 species of big cats, including leopards. They then asked volunteers to classify the markings according to features such as complexity, regularity, size and whether they were spotted or striped. While previous studies have used advanced mathematical techniques to perform this type of analysis, the scientists used humans to classify the patterns; computers can struggle to identify similar patterns from photographs taken under different lighting conditions but humans are much better at spotting such similarities.
Having classified the different cat species, the researchers set about analysing whether there was any connection between the type of marking on a cat’s coat and its habitat and lifestyle. They discovered that with a few exceptions, the markings perfectly mirrored the cats’ environments and behaviour. As the authors state (quoting from Kipling’s much loved children’s story): “Evolution has generally paired plain cats with relatively uniformly coloured, textured and illuminated environments and patterned cats with environments ‘full of trees and bushes and stripy, speckly, patchy-blatchy shadows.’”
While it might not seem surprising that big cats’ coats correspond to their environments for camouflage, remarkably little research has been done in the area. The authors point out that their methods could be extended to other patterned species and suggest that “A challenge for the future...is to understand when and where particular camouflage solutions and other colouration patterns are employed.”