Birds can see colours, just as people do. Birds need to see colours when they fly because they need to find places to land (着陆). Colours help them know 1 the place is and what it is like so that they can catch flying things in the air or land on something they think safe.
Birds can "tell" the differences between colours. But for some 2 animals, such as wolves, the world looks like a black and white photo. Wolves look for food mainly by 3 .
They can hear 4 when the animals they hunt move. But other animals seem to know this. For example, a rabbit will stop moving when it finds there is something 5 . Then the wolves 6 not find it at all. However, birds are better than wolves in these ways. They can see dead insects from far away.
Some birds' eyesight is 7 than people's. They can see small insects 8 they fly in the sky. Because they are able to 9 colours, they can find food easily and 10 if (是否) there are other animals that are dangerous to them.
