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All about birds – Bones and skeleton.
Did you know birds need to be light in weight? They use a lot of energy flapping their wings to take off and fly. So the bones that make up a bird's skeleton must be light as well as strong to do their job. A bird’s main limb bones are hollow, with special struts inside to strengthen them. This makes them strong. Have you ever tried to see how much weight a paper tube can hold? Why not try a few paper tubes stuck together in a bundle? Perhaps you could make your own paper tubes from newspaper or use paper drinking straws? Finding out how strong tubes can be will help you understand that a bird's skeleton is light weight as well as strong.
Different shapes and sizes
The largest common bird in Britain is the Mute swan with a wingspan of 223cm and weight of 11.5 kilogrammes (male). The smallest birds in Britain are the Goldcrest and Firecrest - tiny birds with a 14 centimetre wingspan and weigh just 6 grammes. At this time of year you can often hear Goldcrest singing. A high pitched - "zezezezezee" from trees and hedges where they search for insects flitting from one branch to the next - they just don't keep still!
The world's largest living bird is the Ostrich and that can weigh up to 136 kilogrammes and stand up to 2.5 metres tall. The smallest bird in the world is the Bee Hummingbird of Cuba which weighs about 1.8 grammes and is only 5.7 centimetres long! The biggest wingspan is the amazing Wandering Albatross, 3.6 metres wide!
Top: Bird Skeleton Cardboard Tubes
Bottom: Goldcrest Mute Swan Ostrich