In Rudyard Kipling’s children’s tale, the leopard was initially a “greyish-yellowish catty-shaped kind of beast”.
He was hopeless at hunting until a kindly Ethiopian gave him spots with which to conceal himself both on stony ground in the open or under sun-dappled trees.
British scientists, in a study, have given data to flesh out Kipling’s whimsy, confirming how stripes and spots worn by the big cats fit neatly with their habitat.
A team led by University of Bristol experimental psychologist Will Allen analysed images of 37 species of felidae, from the wildcat to the clouded leopard, transcribing the complexity of their fur patterns into mathematical formulae.
The equations were then matched against data for the cats’ habitat and behaviour – where they lived (savannah, forest, mountains and so on) and when and how they hunted (daytime, nighttime, and so forth).
“We found that cats which live in closed habitats such as forests are much more likely to be patterned, especially with particularly irregular or complex patterns, than those that live in open habitats,” remarked Dr Allen.
Complex and irregular patterns are good camouflage in dense tropical forests, he explained.
“This is especially true of cats which spend more time active in trees and at lower light levels,” such as nocturnal hunters such as jaguars, he said.
One mystery, though, is why the tiger’s clever stripes are not more widely distributed among forest cats.
In contrast, cats which operate in the open, such as mountain-loving pumas, also called cougars, tend to have a non-patterned fur.
The leopard, as Kipling’s tale suggests, comes halfway in between: his simple, regularly-patterned spots give excellent cover for stalking in the grasslands and rocks of the savannah and for sleeping in the branches of trees.
A look at the evolutionary history of felids, as big cats are called, suggests that patterns have come and gone over thousands of years as species adapt to pressure from habitat, Dr Allen added.
“Cats have radiated rapidly to occupy varied environmental niches and their patterning has adapted accordingly in most cases,” he said.