Birds belong to the biological class Aves and live virtually everywhere on Earth. Birds are amniotes, animals whose eggs are protected from drying out (a group that includes the mammals, birds, dinosaurs, and reptiles). There are about 9,000 different species of birds, divided into 24 orders and 146 Families. Most birds alive today are Neognathae (a group distinguished by common palate structure). Another, much smaller group, is the Palaeognathae (again grouped by palate structure), which includes the ostrich, kiwi, emu, rhea, and others.
The Evolution of Birds:
Birds probably evolved from meat-eating (theropod) dinosaurs during the Mesozoic Era, roughly 150 million years ago. Early birds, like Archaeopteryx, had teeth in their mouth and claws on their wings.
Bird Songs:
Birds sing beautiful and diversified songs. Many songbirds are becoming scarcer every year.
Songbirds have a vocal organ called the syrinx located in the throat. The muscular syrinx has two halves that each vibrate to produce songs, so the bird can sing two notes at a time. To sing, a bird blows air from the lungs through the syrinx.
The Evolution of Birds:
Birds probably evolved from meat-eating (theropod) dinosaurs during the Mesozoic Era, roughly 150 million years ago. Early birds, like Archaeopteryx, had teeth in their mouth and claws on their wings.
Bird Songs:
Birds sing beautiful and diversified songs. Many songbirds are becoming scarcer every year.
Songbirds have a vocal organ called the syrinx located in the throat. The muscular syrinx has two halves that each vibrate to produce songs, so the bird can sing two notes at a time. To sing, a bird blows air from the lungs through the syrinx.
1 comment:
Hi samia .... this is nice blog and also the pictuers....
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