Bird: Difference between revisions
imported>Aleta Curry (We've got cranes, penguins and orioles and fights over parrots, but no BIRDS?) |
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Birds are a class of animals (''aves'') that can be distinguished from all other living animals by the presence of [[feather]]s. They are two-legged, warm-blooded [[vertebrate]]s with [[wing]]s and they range greatly in size, the tiniest can fit on the palm of a human hand and the largest can be ridden upon. The largest living bird species (the [[Ostrich]]es are flightless. Flight does not distinguish birds, because many insects have wings and can fly. | Birds are a class of animals (''aves'') that can be distinguished from all other living animals by the presence of [[feather]]s. They are two-legged, warm-blooded [[vertebrate]]s with [[wing]]s and they range greatly in size, the tiniest can fit on the palm of a human hand and the largest can be ridden upon. The largest living bird species (the [[Ostrich]]es) are flightless. Flight does not distinguish birds, because many insects have wings and can fly. | ||
Most bird species exhibit [[sexual dimorphism]] to some degree, that is, that male and female birds look different. It is usually the males which are the more brightly coloured. | |||
There are more than 9,000 different bird species. | Birds reproduce by laying [[egg]]s, as do reptiles and amphibians. The eggs are usually placed in nests, some of very intricate construction, some very casually put together, and incubated for a period. | ||
Birds are extremely valuable to humans in several respects. Domestic birds are raised for eggs and meat, called [[poultry]], and many wild bird species are hunted for food. Other species are kept as [[pet]]s. In addition, many birds eat insects that humans find irritating or destructive, and they consume [[weed]] [[seed]]s. Finally, birds act as useful [[scavenger]]s around areas of human habitat. | |||
There are more than 9,000 different bird species. In terms of evolution, they are the most successful of the vertebrates; this is largely attributed to their ability to fly, which allows them to roam great areas and search out and adapt to a wide range of habitats. | |||
==Types of bird== | ==Types of bird== | ||
Revision as of 15:16, 11 June 2010
Birds are a class of animals (aves) that can be distinguished from all other living animals by the presence of feathers. They are two-legged, warm-blooded vertebrates with wings and they range greatly in size, the tiniest can fit on the palm of a human hand and the largest can be ridden upon. The largest living bird species (the Ostriches) are flightless. Flight does not distinguish birds, because many insects have wings and can fly.
Most bird species exhibit sexual dimorphism to some degree, that is, that male and female birds look different. It is usually the males which are the more brightly coloured.
Birds reproduce by laying eggs, as do reptiles and amphibians. The eggs are usually placed in nests, some of very intricate construction, some very casually put together, and incubated for a period.
Birds are extremely valuable to humans in several respects. Domestic birds are raised for eggs and meat, called poultry, and many wild bird species are hunted for food. Other species are kept as pets. In addition, many birds eat insects that humans find irritating or destructive, and they consume weed seeds. Finally, birds act as useful scavengers around areas of human habitat.
There are more than 9,000 different bird species. In terms of evolution, they are the most successful of the vertebrates; this is largely attributed to their ability to fly, which allows them to roam great areas and search out and adapt to a wide range of habitats.
Types of bird
Birds of Prey (raptors)
These include eagles and owls.
Waterfowl
Ducks, geese and swans are examples of waterfowl.