موضوع انشائي قصير باللغة الانجليزية عن الطيور birds
English topics and essays
Birds are a class of vertebrates,
the Aves.
They
are warm-blooded and lay eggs. Their bodies are covered with feathers and they have wings. Feathers have three functions: flight,temperature regulation and display.
Most birds have hollow main bones with air sacs in them.This makes them
lighter and makes flight easier.
Birds
are bipedal: they have two legs
which are often covered with scales (small, flat plates which over-lap in
the same way as feathers). They have a hard beak with no teeth.
Because
birds keep a high body temperature,
they use lots of energy. So, they need to eat a lot of food compared with their
weight.
More
than 9000 different species of birds are known.
Birds
are found on every continent of the world. Birds of different types can live in
freezing cold environments, and
others can live in hotdeserts. Birds live in forests, in grasslands, on cliff
faces, in river banks, on stony sea shores, down mine shafts and in the roofs
of houses.
Different
types of birds eat different foods. Most birds are carnivorous meaning that they eat flesh, at least
some of the time. Many birds live on insects or on fish. Some eat small reptiles and mice. Birds of prey eat mammals and other birds. Some birds are scavengersand eat the bodies of
creatures that have died. Many birds such as parrots and finches live on seeds and fruit. Some birds
that eat mainly seeds feed their young on insects. A few types of birds eat
green plants, but only one species lives on leaves. Hummingbirdsand Honeyeaters live on
the nectar or honey in flowers.
Birds
come in many sizes from the Bee
Hummingbird that is only
60 mm long to the ostrich which stands 2.5 metres high. The bird
with the widest wingspan is the Wandering Albatross many of which measure 3 metres from
tip to tip.
All
this applies to living birds. Birds are the descendants of theropod dinosaurs, and the early birds looked
much like small carnivorousdinosaurs.
Much is now known about the origin
of birds. From fossils we know that these dinosaurs had
feathers, and early birds had teeth.
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