Tuesday 31st March
Click to play Read by Matthew
So far I've talked about observing, identifying and classifying birds. BUT what is a bird??? Can you think of the ONE special feature that no other animal has - the one things that tells you that the animal you are looking at is a bird. That's right - feathers. All birds have feathers. A beautiful piece of biology that is designed for flight, warmth and colour.
When I watched the birds sleeping in the bird boxes last week I noticed that they didn't look like they normally do. The Great tit was all fluffy - it looked a bit like a mouse with a feather for a tail! The Great tit always looks so handsome, smooth and shiny, so why was the bird in the box so fluffy? It is still very cold at night-time so the little birds puff up their feathers. Birds have light-weight fluffy feathers called "down" underneath their outer feathers. These feathers hold air close to the skin so that heat cannot be lost from their body. That's how duvet covers work - lots of pockets of air to stop heat escaping. Ducks and swans have a lot more feathers than birds that live on land - can you think why?
The outer feather are very strong, but also very light. These are the feathers that are used for flying. People designing aeroplanes will look at the shape of bird's wings and feather to help them design the best, fastest, safest planes. The feathers are aerodynamic which means that they cut through the air very easily. The feather is made from little "barbs" that all hook together to make one whole feather. If you brush a feather the wrong way all the barbs become detached and ruffled. If you smooth a feather the right way you are putting the hooks on the barbs back together - a bit like Velcro!
Birds also have an amazing variety of colours in their feathers. From the electric blue of a Kingfisher and the bold red Bullfinch to the "Little Brown birds" such as House sparrows and Dunnock. These colours are often bright on the male birds in order to show off to the ladies. The female birds, such as Mallards, Pheasants and Bullfinches are all brown - can you think why this is useful if you are sitting on the nest? There are some exceptions - can you research Grey phalarope?
Feathers are so important to birds that they grow a new set each year, this is called moulting. Springtime is when birds look the smartest, before they have chicks. By the summer some birds can look tired and very tatty - it's hard work bringing up a family!