The birds portal
Welcome to the Birds Portal! Birds
) are bipedal
, oviparous vertebrate animals
. Most scientists believe that birds evolved
from theropod dinosaurs
. Ranging in size from tiny hummingbirds
to the huge ostrich
, there are between 9,000 and 10,000 known living bird species in the world, making Aves
the most diverse class of terrestrial vertebrate
A bird is characterized by feathers, a toothless beak, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a light but strong skeleton. All birds have forelimbs modified as wings and most can fly.
Birds are important sources of food, acquired either through farming or hunting. Numerous species of birds are also used commercially, and some species, particularly songbirds and parrots, are popular pets. Birds figure prominently in all aspects of human culture from religion to poetry and popular music. Numerous species of birds are threatened with extinction by human activities and as a result efforts are underway to protect them.
that have adapted
to life within the marine
environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution
, as the same environmental problems and feeding niches
have resulted in similar adaptations. The first seabirds evolved in the Cretaceous period
, and modern seabird families emerged in the Paleogene
In general, seabirds live longer, breed later and have fewer young than other birds, but they invest a great deal of time in their young. Most species nest in colonies, which can vary in size from a few dozen birds to millions. Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Seabirds can be highly pelagic, coastal, or in some cases spend a part of the year away from the sea entirely.
Seabirds and humans have a long history together: they have provided food to hunters, guided fishermen to fishing stocks and led sailors to land. Many species are currently threatened by human activities, and conservation efforts are under way.
The red-crested pochard (Netta rufina) is a large diving duck. Its breeding habitat is lowland marshes and lakes in southern Europe and southern and central Asia. It is somewhat migratory, and northern birds winter further south and into north Africa.
||When I see a bird that walks like a duck and swims like a duck
and quacks like a duck, I call that bird a duck.
Free online resources:
There is also Birds of North America, Cornell University's massive project collecting information on every breeding bird in the ABA area. It is available for US$40 a year.
For more sources, including printed sources, see WikiProject Birds.
The red-tailed black cockatoo
), also known as Banksian-
or Bank's black cockatoo
, is a large cockatoo
native to Australia
. It is more common in the drier parts of the continent. Five subspecies are recognised, differing most significantly in beak size. Although the more northerly subspecies are widespread, the two southern subspecies, the forest red-tailed black cockatoo
and the south-eastern red-tailed black cockatoo
are under threat. Adult red-tailed black cockatoos are around 60 centimetres (24 in) in length and sexually dimorphic
. Males are completely black in colour, excepting their prominent red tail bands; the slightly smaller females are brownish-black with yellow barring and spotting and have yellow-orange tail stripes. The species is usually found in eucalyptus
woodlands, or along water courses. In the more northerly parts of the country, these cockatoos are commonly seen in large flocks. They are seed eaters and cavity nesters. Of the black cockatoos, the red-tailed black is the most adaptable to aviculture, although black cockatoos are much rarer and much more expensive outside Australia.
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Taxonomy of Aves
|Class Aves, divided into superorders, orders, suborders (where indicated), and families.