Aves

Bird Families of the World - Don Roberson's detailed guides to about half of the world's 202 bird families.
http://montereybay.com/creagrus/list.html

Birds of the World - Lists of all species with scientific and English names, subdivided by Family. Choice of list based on the Clements or the Sibley and Monroe classification schemes.
http://birdingonthe.net/clements/Clements.html

Bird On! - Internet wild bird pages including information on a bird book, bird news, bird care, a bird album and short articles of a number of bird species.
http://birdcare.com/birdon/

Eggs - A Virtual Exhibition - The Provincial Museum of Alberta's on-line, searchable, field guide of over 300 bird eggs. Global, with emphasis on birds of Alberta. Includes photos and taxonomic information.
http://www.royalalbertamuseum.ca/vexhibit/eggs/vexhome/egghome.htm

About: Birds - Class Aves - Educational site outlining the characteristics of birds, their biology and classification.
http://animals.about.com/od/birds/p/aves.htm

A Field Guide to the Birds on the Web - Links to pictures, sounds, and video of the birds of the world, systematically indexed.
http://fieldguide.tripod.com/

Bird Hybrids Database - Worldwide database compiled from the ornithological literature of birds with two different species as parents. Includes complete references for each species combination. In English, French, and Spanish.
http://www.bird-hybrids.com/

Birds of North American, Audubon's Watercolors - Fifty-one images of North American birds from watercolors done by John James Audubon. List can be browsed by common or scientific name.
http://www.nature.net/birds/

Birds of North America - A reference series on North American birds, with information and sample profiles.
http://bna.birds.cornell.edu/BNA/

Birds of the World - List of current valid scientific avian names subdivided by order and family, based on the Sibley and Monroe and AOU lists. Includes scientific names and publication details.
http://www.zoonomen.net/avtax/frame.html

Exotic Pet Veterinarian - Avian Anatomy - Describes the anatomy and physiology of birds for the lay audience, explaining technical terms along the way. Some emphasis on details of psittacines.
http://www.exoticpetvet.net/avian/anatomy.html

Birdhybrids - Mailing list for discussion of bird hybrids.
http://fr.groups.yahoo.com/group/birdhybrids/

Photographs by Victor, Ornithonut - Photographs of over 100 species found in Eastern Ontario and Western Quebec.
http://www.igs.net/~vfl/

Avibase - An extensive database information system about all birds of the world, containing nearly 1 million records about 10,000 species and 22,000 subspecies of birds, including distribution information, taxonomy, and synonyms in several languages.
http://www.bsc-eoc.org/avibase/avibase.jsp

The Internet Bird Collection - Video library of footage of the world's birds, sponsored by the Handbook of the Birds of the World.
http://www.hbw.com/ibc/

Multilingual Bird Search - Translates world bird names between several languages, including scientific names. Includes photo gallery.
http://www.knutas.com/birdsearch/

Wildlife Bird Photography in Greece - This gallery of photographs by Panos Oikonomou, besides many varieties of bird, includes mammals and a few reptiles and amphibians, all photographed in the wild.
http://www.wildlifebirdphotography.gr/

History of North American Bird Names - Details all the changes in the American Ornithologists' Union Checklists from 1886 - 2000.
http://members.aol.com/darwinpage/zoo/AOUmenu.htm

John Penhallurick's Bird Data Project - Attempt to build a database about the birds of the world, both extant and extinct since 1600.
http://worldbirdinfo.net/

Handbook of the Birds of the World - Information about the book series that will illustrate and deal in detail with all the species of birds in the world. Tables of contents, sample pages, and publication schedule.
http://www.hbw.com/

Mango Verde - Photos and sounds for almost 2000 bird species; field guide quick indices.
http://www.mangoverde.com/

Introduction to the Aves - Scientific background and information on birds.
http://www.ucmp.berkeley.edu/diapsids/birds/birdintro.html

Virtual Bird - A collection of bird photographs, videos, and songs from North America and Europe (mainly Finland).
http://www.virtual-bird.com/

American Ornithologists' Union Check-list of North American Birds, Seventh Edition - Official source on the taxonomy of birds found in North and Middle America, including adjacent islands. The full list of bird species (with scientific and English names) is online in HTML, .pdf, and Excel formats.
http://www.aou.org/checklist/

National Bird Collection - With roughly 640,000 specimens from around the world, this collection is located in Washington, DC, USA.
http://vertebrates.si.edu/birds/

Bird Families of the World - Short descriptions and sounds of the world's bird families by Chris Butler.
http://www.eeb.cornell.edu/winkler/botw/Main.html

Class Aves - Provides a definition of birds (Aves) and describes their traits.
http://animaldiversity.ummz.umich.edu/site/accounts/information/Aves.html