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A passerine is a bird of the giant order
Passeriformes. More than half of all species of bird are passerines. Sometimes known as perching birds
or, less accurately, as songbirds, the passerines are one of the most spectacularly successful vertebrate orders: with around 5,400 species, they are roughly twice as diverse as the most successful of the mammal orders, the Rodentia.
The group gets its name from the Latin name for the House Sparrow, Passer domesticus.
Characteristics
Many passerines are songbirds and have complex muscles to control their syrinx; all of them gape in
the nest as infants to beg for food.
The order is divided into two suborders, Tyranni, and Passeri (oscines). Oscines have the most control of their syrinx muscles
and are true songbirds (though some of them, such as the crow, do not sound like it).
Most passerines are smaller than typical members of other avian orders.
Origin
The evolutionary history of and relationships among the passerine families remained rather mysterious until around the end of
the 20th century. Many passerine families were grouped together on the basis of morphological similarities which, it is now
known, are the result of convergent evolution, not a close
genetic relationship. For example, the "wrens" of the northern hemisphere, of Australia, and of New Zealand all look very similar
and behave in similar ways, and yet belong to three far-flung branches of the passerine family tree: they are as unrelated as it
is possible to be while yet remaining Passeriformes.
Much research remains to be done, but a series of biochemical studies are gradually revealing a clearer picture of passerine
origins and evolution. It is now thought that the early passerines evolved in Gondwana at about the time that the southern supercontinent was breaking up. This led to the Tyranni and, a little later, to a great radiation of forms in Australia-New Guinea (the Passeri or songbirds). A major branch of the passerine tree, the Passerida (or sparrow-like forms), emerged
either as the sister group to another (the Corvida, or crow-like birds), or more likely as a subgroup of the Corvida, and reached
the northern hemisphere, where there was a further explosive radiation of new species. Since then, there has been extensive
mixing, with northern forms returning to the south, southern forms moving north, and so on.
List of passerines
- ORDER PASSERIFORMES
- Suborder Tyranni
- Suborder Passeri
- Parvorder Corvida
- Parvorder Passerida
See also
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