From Opus

Common Raven
Photo by bobsofpa

Family: Corvidae

[edit] Description

Around 125 species of Crows, Jays and Magpies are found worldwide. They inhabit all continents except Antarctica.
Basic features of the corvids are:

• long tarsi
• stiffened primaries and tail feathers
• tuft of nasal bristles extending to the nostril opening
• an unspotted juvenile plumage (ecxept Crested Jay)

The body size in this family is quite variable. Ravens and Crows can be quite large whereas jays and magpies are only medium-sized. The Common Raven is the largest passerine in the world, reaching 69cm in length and 2kgs in weight. On the other hand the Dwarf Jay of Mexico with 20cm and 40gr is the smallest corvid.
The corvids are one of the best-known avian groups and they have fascinated man for a long time. Images of them are found on cave wall paintings made by the early humans. Their curiosity, memory, attractive movement, varied vocalizations and ecological plasticity have intrigued people around the world.

Plush-crested Jay
Photo by Gary Clark

[edit] Taxonomy

Corvidae is a Family in the Order Passeriformes.
Studies indicate that the family is monophyletic which means that all corvids have the same ancestor. This species lived most probably in today's Australia some 53 million years ago.
The relationsship within the other avian families has been discussed for a long time. New work indicate that the Birds-of-Paradise are the sister-group of the corvids and that the Bowerbirds, the Shrikes and the Vireos are also closely related to them.
The taxonomic placement of the Crested Jay is still unsure and it may not be a corvid at all.

[edit] References

1. Clements, JF. 2009. The Clements Checklist of Birds of the World. 6th ed., with updates to December 2009. Ithaca: Cornell Univ. Press. ISBN 978-0801445019.
2. Del Hoyo, J, A Elliott, and D Christie, eds. 2009. Handbook of the Birds of the World. Volume 14: Bush-shrikes to Old World Sparrows. Barcelona: Lynx Edicions. ISBN 978-8496553507

• List of references