Grade Six Science

Hello Boys and Girls,

Have you completed your revision for the NGSA ‘Mock Exam’ this week? Please do your best. Do well.

Last week, we looked at birds. Let’s continue to examine them. We saw that birds are covered with feathers. Do you remember the functions of the feathers? Let’s look at the feather below.

A feather is composed of three parts – a shaft (quill), barbs and barbules. These feathers grip together as the wing moves downwards, to resist the air. They tend to unlink as it moves forward. This reduces its resistance to the air. The feather on the wings and tail are larger, stronger and stiffer than the others. The contour or covert feathers cover the body. The down feathers can be found on the neck and wings and over the body.

As you know, the feathers of birds are not only for flying, but they serve to protect them as well as to help to keep them warm.

Let’s look at the wings of birds. The wings of birds help them to fly. These wings may be long or short, round or pointed. The shape of the wings helps in the way the bird flies – gliding, soaring, flapping.

Nearly all birds have a tail, which helps them control the direction in which they fly. It also plays a role in landing. Tails may be square, round, pointed or forked. Observe the birds in your garden or anywhere nearby to observe these features.

The feathers on the tail and wings are usually long. Those under the neck and head are short and are called down feathers. Those on the rest of the body are called covert feathers.

How many legs do birds have? Yes, birds have two legs, and most birds have four toes on each foot. In most cases, the first toe points backwards. The toes of birds can be suited for perching, grasping, climbing and so on.

Do birds have teeth? No, birds do not have teeth in their beaks or bills. Have you ever examined the beaks of birds closely? Beaks may be of different shapes and sizes, depending on the type of food the bird eats.

The eyes of birds are large and provide excellent vision. Their ears are completely internal, with openings placed just below the eyes. Birds rely on their ears for hearing and also for balance, which is so important during flight.

Birds lay eggs, which have hard shells. Most birds lay their eggs in nests. The young which hatch from the egg is called a chick. The mother birds hatch their eggs and take care of the chicks until they can fly or fend for themselves. They feed the chicks and keep them warm.

Adaptation

Let’s examine how birds have adapted.

The beaks and feet of birds are adapted according to how they feed and live. Let’s look at their feet. Look at the feet below.

Feet of Birds

Look at the webbed feet for swimming. Do you see the skin between the toes? Many birds are excellent swimmers. Ducks and swans are good examples. They use their webbed toes as paddles to propel themselves in the water.

Some toes are for grasping, for perching, for climbing and for carrying. Some birds move by walking, hopping or running. Did you know that the ostrich can run as fast as 64 km/h (40 mph)?

Birds that walk in shallow water, such as herons, have long legs for easy wading.

Look at these beaks. Can you tell how they feed?

Nectar feeding birds, such as humming birds, have long thin bills which they insert into flowers and eventually get nectar.

Meat-eating birds, including hawks and owls, have strong, hooked bills that can tear flesh. Many fish-eating birds, such as some ducks, have toothlike ridges on their bills that help them to hold their slippery prey. The thick bills and strong jaw muscles of various finches and sparrows are ideal for crushing seeds. Woodpeckers use their bills as chisels, working into dead or living wood to find insect larvae and excavate nest cavities.

An assignment for you:

List the names of as many birds found in Guyana as you can. Compare with students in your class.

Have a great week, and until next week, goodbye Boys and Girls! Continue to do everything you can to be safe.