If you enjoy watching birds you probably have at least one bird book you use for helping to identify species. And if you travel to different countries, you may well have a collection of bird books. Bird books, also called field guides, often display many related species on the same page; or if not the same page, then on nearby pages. This lets one glance from species to species, compare the similarities and differences, and more easily identify a species you are not familiar with.
This website is designed to serve as an online bird book. For ease of comparison, there are many species of birds on a web page. There are also links to similar birds that further help to compare species. And there are links to more online information for each species. The web pages are organized by genus and bird family. Families are often grouped together by related functions. For example, there are raptor pages for eagles, falcons, hawks, kites, owls, and vultures. There are entries for over 10,000 species.