الأسبوع 17 · المحور 3، الباب 1 «أنماط التغير» (ب): تكيف الكائنات الحية والشحم والتمويه · 3 دروس
3
Hide and seek: camouflage
Discover P3 Term 2: Axis 3, Chapter 1
GoalExplain how camouflage helps animals survive, compare hiding places around school, and design a camouflaged bird.
New words
camouflage · colours, patterns or shapes that make an animal hard to see where it livespredator · an animal that hunts other animals for foodprey · an animal that is hunted for foodblend in · to look so much like the background that you are hard to see
Explanation
Some animals are hard to see because their colours and patterns match where they live. This is called camouflage. A desert lizard that is sandy brown is hard to see on sand. A polar bear’s white fur is hard to see on snow. Camouflage helps in two ways. Prey animals can hide from predators, and predators can creep close to their prey without being seen. A camouflage only works in the right habitat. A sandy lizard on green grass would be easy to spot. When you design a camouflaged animal, first look at the colours, lines and shapes of the habitat, and then use the same ones on the animal.
Worked examples
Where would each colour hide best? Brown hides on sand and bark. Green hides in leaves. White hides in snow.
A fair test with paper bugs. Habiba cut out 10 green and 10 brown paper bugs, and a grown-up scattered them on grass. The class searched for 30 seconds. They found 3 green bugs and 7 brown bugs. Brown bugs were found more often, so on grass the green ones were harder to find: 7 − 3 = 4 more brown ones.
A camouflaged bird. For a bird living among palm trunks and dry fronds, Farida used brown and yellow-brown with thin lines, like the trunk.
Class activity
Hide and find. With a grown-up, cut 10 green and 10 brown bugs from card. A grown-up scatters them on grass or in a leafy corner of the yard. Predict: which colour will be found more? Search for 30 seconds, write the numbers and draw a bar chart. Then design a bird on paper that hides in a habitat you choose, for example a palm grove, the Nile bank or a sandy desert. Use the colours and lines of that habitat. Pick up all the paper bugs afterwards.
Practice
1
What is camouflage?
Colours or patterns that make an animal hard to see where it lives.
2
Why would a sandy brown lizard be easy to see on bright green grass?
Its colour does not match the grass, so it does not blend in.
3
In a search on a corner covered with dry brown leaves, the class found 8 green bugs and 3 brown bugs. How many more green bugs were found, and what does it show?
8 − 3 = 5 more green bugs were found. The brown bugs were found less often, so they hid better among the dry brown leaves.
4
Name one animal that uses camouflage and the habitat where it hides.
For example, a sandy lizard in the desert or a polar bear in the snow.
