Speaker: Rachel Roberts (Standard British accent)

Many animals use camouflage to make them harder to see. Hunters do this so that the animals they want to eat don’t see them and run away. And prey animals, such as deer and zebra, use camouflage to avoid being eaten. But why do large cats have such different patterns? Lions don’t have any spots at all, but cheetahs have small black spots. Tigers, on the other hand, have large black stripes and orange fur, while leopards and jaguars have much more complicated patterns of spots. 

research

Will Allen at the University of Bristol is interested in this subject. For his Ph.D. in vision science, he decided to study large cats to try to find out the reasons for these different patterns. He says that, to find the answer, he also needed to talk to scientists from many different fields, such as psychology, biology, engineering and computer science. Experts from each of these areas of science helped him with his work. 

patterns

Earlier studies had shown that camouflage was more common among cats that lived in forests. But Will Allen says that these studies didn’t explain why a leopard’s spots are different from a cheetah’s, for example. He decided to use a mathematical technique called "reaction-diffusion." This allowed him to play with different patterns on a computer screen and produce exact matches for different animals. In this way, he could compare camouflage patterns with the animals’ behaviour and habitat much more accurately.

HABITAT

These results help to explain the differences. Will says that there is a clear connection between patterns and environment. Cats in forests with lots of trees and plants have more complicated patterns than cats which live in areas without lots of trees. And cats that spend more time in trees have more irregular patterns than cats that hunt at night. Will explains that a cat’s camouflage depends on where it lives and how it hunts. Evolution has created the most suitable pattern for each particular hunter. Will Allen’s studies mean we can look at a big cat’s fur and predict its habitat and lifestyle.