Birds the Only Animals That Could Fly
Birds are vertebrate animals with feathers.
There are over 10,000 species living today and they are spread in a geographical area from Arctic to Antarctic.
When it comes to size the bee humming-bird is only 2 inches while the biggest bird ostrich is 9 ft.
Present day birds do not have teeth.
They only have bills.
They lay hard-shelled eggs.
They have light weight but strong skeletons and their hearts have four chambers.
All species living at present have wings but all don't fly.
Penguins are one of the flightless species.
Some of them are among the most intelligent of animals.
Some are able to make tools and use them.
Parrot is one of the most intelligent birds.
They have digestive systems and respiratory systems that are well-adjusted for flight.
There are some that transmit their knowledge through generations.
Some birds migrate seasonally long distances while there are others that are roaming constantly.
They are also social and flock together for hunting.
They are able to mob their prey.
Most of them are also monogamous.
Sometimes the bond lasts one season.
Rarely does it go on for a few mating seasons.
But they never continue their relationships for life.
There are also polygamous species.
The eggs are laid in nests and the parents do the incubation.
Once the young birds emerge parents look after them until they are able to manage alone.
Many of the species are important to humans economically.
Some of them are being hunted while there are others that are domesticated for eggs and their droppings that could be used as manure.
There are many occasions where birds are involved with religion poetry and popular music.
Around 12 species of them have already gone extinct after 17th century.
Also there are 1200 species that are treated as endangered.
All birds have feathers and they help them to fly and to preserve body temperature.
Also, some of them use feathers for signaling also.
There are several types of feathers and they serve different purposes.
In order to have the feathers in peak condition they need to be groomed on daily basis.
Birds spend 9% of their time for this purpose.
They use their beaks to remove foreign matter from their feathers.
At the same time they apply a waxy secretion on their feathers.
This will remove bacteria that could damage feathers.
Also, it will maintain their flexibility.
There are over 10,000 species living today and they are spread in a geographical area from Arctic to Antarctic.
When it comes to size the bee humming-bird is only 2 inches while the biggest bird ostrich is 9 ft.
Present day birds do not have teeth.
They only have bills.
They lay hard-shelled eggs.
They have light weight but strong skeletons and their hearts have four chambers.
All species living at present have wings but all don't fly.
Penguins are one of the flightless species.
Some of them are among the most intelligent of animals.
Some are able to make tools and use them.
Parrot is one of the most intelligent birds.
They have digestive systems and respiratory systems that are well-adjusted for flight.
There are some that transmit their knowledge through generations.
Some birds migrate seasonally long distances while there are others that are roaming constantly.
They are also social and flock together for hunting.
They are able to mob their prey.
Most of them are also monogamous.
Sometimes the bond lasts one season.
Rarely does it go on for a few mating seasons.
But they never continue their relationships for life.
There are also polygamous species.
The eggs are laid in nests and the parents do the incubation.
Once the young birds emerge parents look after them until they are able to manage alone.
Many of the species are important to humans economically.
Some of them are being hunted while there are others that are domesticated for eggs and their droppings that could be used as manure.
There are many occasions where birds are involved with religion poetry and popular music.
Around 12 species of them have already gone extinct after 17th century.
Also there are 1200 species that are treated as endangered.
All birds have feathers and they help them to fly and to preserve body temperature.
Also, some of them use feathers for signaling also.
There are several types of feathers and they serve different purposes.
In order to have the feathers in peak condition they need to be groomed on daily basis.
Birds spend 9% of their time for this purpose.
They use their beaks to remove foreign matter from their feathers.
At the same time they apply a waxy secretion on their feathers.
This will remove bacteria that could damage feathers.
Also, it will maintain their flexibility.
Source...