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The Camouflage of Cats
This simplified version by Russell Evans， adapted from the original article by John O’Reilly.
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. While tigers have large black stripes and orange fur， leopards and jaguars have much more complicated patterns of spots.
Will Allen at the University of Bristol is interested in this question. For his PhD in vision science， he decided to study large cats to try to find out the reasons for these different patterns. Will 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.
Earlier studies had shown that camouflage was more common among cats that lived in forests. But Will says that these studies didn’t explain why a leopard’s spots are different from a cheetah’s spots， 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.
His 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’s studies mean we can look at a big cat’s fur and predict its habitat and lifestyle.
You are going to read about why different large cats have different colours and patterns on their fur. Before you read， can you name these big cats？
Activity 1
Before you read， match the word or phrase to a definition.
1. camouflage 2. depend upon 3. evolution
4. habitat 5. irregular 6. mathematical 7. prey 8. psychology 9. vision
a. a way to hide things by making them look the same as the natural background
maths and numbers
an animal which is hunted and eaten by another animal
be changed or affected by something
having different shapes， sizes and colours
the ability to see things
the kind of place where an animal lives， for example desert or jungle
the study of the mind and behaviour
the way plants and animals change over long periods of time
Activity 2
Choose one word from the text to complete each sentence.
1. Both hunters and ______ animals use camouflage because they don’t want to be seen.
2. Will Allen wanted to understand why different large cats had different ______ on their fur.
3. He needed help from different ______ in sciences such as biology and engineering.
4. Using ‘reaction-diffusion’ allowed him to ______ animal lifestyles and the patterns on their fur.
5. His research suggests that if there are lots of ______ in an animal’s habitat， their camouflage patterns are more complicated.
Activity 3
Look at these two sentences from the text and the words in bold.
Lions don’t have any spots at all， but cheetahs have small black spots.
While tigers have large black stripes and orange fur， leopards and jaguars have much more complicated patterns of spots.
Both sentences use linking words to join contrasting ideas in a single sentence. In these examples but is in the middle of the sentence and while is at the start.
Rewrite these pairs of sentences using either but in the middle or while at the start.
1. I like chocolate ice cream. My sister doesn’t.
2. Jack is studying maths. Jill is studying English.
3. My dad loves watching football. My mum likes watching tennis.
4. They listen to rap music. We prefer rock music.
5. Leopards eat meat. Zebra eat grass.
6. We would like to visit Japan on holiday. Our friends want to go to New Zealand.
Activity 4
Camouflage patterns used by soldiers are sometimes used in fashion clothing. Why do you think this is？
Which big cat do you think has the most beautiful fur？ Why？
Answers
Big cats
1. lion; 2. tiger; 3. cheetah; 4. snow leopard; 5. jaguar
Activity 1
1. a; 2. d; 3. i; 4. g; 5. e; 6. b; 7. c; 8. h; 9. f
Activity 2
1. prey; 2. patterns; 3. experts/scientists; 4. compare; 5. trees
Activity 3
1. I like chocolate ice cream， but my sister doesn’t. / While I like chocolate ice cream， my sister doesn’t.
2. Jack is studying maths， but Jill is studying English. / While Jack is studying maths， Jill is studying English.
3. My dad loves watching football， but my mum likes watching tennis. / While my dad loves watching football， my mum likes watching tennis.
4. They listen to rap music， but we prefer rock music. / While they listen to rap music， we prefer rock music.
5. Leopards eat meat， but zebra eat grass. / While leopards eat meat， zebra eat grass.
6. We would like to visit Japan on holiday， but our friends want to go to New Zealand. / While we would like to visit Japan on holiday， our friends want to go to New Zealand.
This simplified version by Russell Evans， adapted from the original article by John O’Reilly.
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. While tigers have large black stripes and orange fur， leopards and jaguars have much more complicated patterns of spots.
Will Allen at the University of Bristol is interested in this question. For his PhD in vision science， he decided to study large cats to try to find out the reasons for these different patterns. Will 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.
Earlier studies had shown that camouflage was more common among cats that lived in forests. But Will says that these studies didn’t explain why a leopard’s spots are different from a cheetah’s spots， 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.
His 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’s studies mean we can look at a big cat’s fur and predict its habitat and lifestyle.
You are going to read about why different large cats have different colours and patterns on their fur. Before you read， can you name these big cats？
Activity 1
Before you read， match the word or phrase to a definition.
1. camouflage 2. depend upon 3. evolution
4. habitat 5. irregular 6. mathematical 7. prey 8. psychology 9. vision
a. a way to hide things by making them look the same as the natural background
maths and numbers
an animal which is hunted and eaten by another animal
be changed or affected by something
having different shapes， sizes and colours
the ability to see things
the kind of place where an animal lives， for example desert or jungle
the study of the mind and behaviour
the way plants and animals change over long periods of time
Activity 2
Choose one word from the text to complete each sentence.
1. Both hunters and ______ animals use camouflage because they don’t want to be seen.
2. Will Allen wanted to understand why different large cats had different ______ on their fur.
3. He needed help from different ______ in sciences such as biology and engineering.
4. Using ‘reaction-diffusion’ allowed him to ______ animal lifestyles and the patterns on their fur.
5. His research suggests that if there are lots of ______ in an animal’s habitat， their camouflage patterns are more complicated.
Activity 3
Look at these two sentences from the text and the words in bold.
Lions don’t have any spots at all， but cheetahs have small black spots.
While tigers have large black stripes and orange fur， leopards and jaguars have much more complicated patterns of spots.
Both sentences use linking words to join contrasting ideas in a single sentence. In these examples but is in the middle of the sentence and while is at the start.
Rewrite these pairs of sentences using either but in the middle or while at the start.
1. I like chocolate ice cream. My sister doesn’t.
2. Jack is studying maths. Jill is studying English.
3. My dad loves watching football. My mum likes watching tennis.
4. They listen to rap music. We prefer rock music.
5. Leopards eat meat. Zebra eat grass.
6. We would like to visit Japan on holiday. Our friends want to go to New Zealand.
Activity 4
Camouflage patterns used by soldiers are sometimes used in fashion clothing. Why do you think this is？
Which big cat do you think has the most beautiful fur？ Why？
Answers
Big cats
1. lion; 2. tiger; 3. cheetah; 4. snow leopard; 5. jaguar
Activity 1
1. a; 2. d; 3. i; 4. g; 5. e; 6. b; 7. c; 8. h; 9. f
Activity 2
1. prey; 2. patterns; 3. experts/scientists; 4. compare; 5. trees
Activity 3
1. I like chocolate ice cream， but my sister doesn’t. / While I like chocolate ice cream， my sister doesn’t.
2. Jack is studying maths， but Jill is studying English. / While Jack is studying maths， Jill is studying English.
3. My dad loves watching football， but my mum likes watching tennis. / While my dad loves watching football， my mum likes watching tennis.
4. They listen to rap music， but we prefer rock music. / While they listen to rap music， we prefer rock music.
5. Leopards eat meat， but zebra eat grass. / While leopards eat meat， zebra eat grass.
6. We would like to visit Japan on holiday， but our friends want to go to New Zealand. / While we would like to visit Japan on holiday， our friends want to go to New Zealand.