This page lists all of the bird Orders found in the world, together with an indication of the number of species occurring in each, and the number of species which have occurred in Britain.

Recently there have been large changes to the order in which birds are listed to better reflect their evolutionary history based on new evidence from DNA studies.

This article provides an overview of the changes or you can read the detailed  recommendations of the British Ornithologists' Union Taxonomic Committee outlining the evidence for the Passerine families.

For some insight into the wider changes in bird taxonomy, you may find the John Boyd's Taxonomy in Flux website useful and for detailed taxonomic information John Penhallurick's World Bird Info site.

For those who wish to read the primary research papers, see the paper by Hackett and others in Science for a study of all the world's birds and that by Thomas in Proceedings B for common British birds.

There is also some disgreement between authorities over the total number of species, and their placement into different Families and Orders (and the order in which they evolved and so are presented in a list).

For example:

• Morony et al. (1975) : 8,982 species in 158 Families
• Monroe & Sibley (1993): 9,702 species in 145 Families
• Clements (2000): 9,716 species in 204 Families
• Dickinson (2003): 9,721 species in 195 Families
• Perrins (2003): 9,845 species in 172 Families

The following table gives the number of species occurring in each Order and the number recorded in Britain.

For those families that have representatives in Britain (either regularly or as wanderers) click on the link to see more details. Note that only families that have occurred in Britain are listed.

This list reflects the 'official' British list as determined by the British Ornithologists' Union, which has adopted some, but not all of the changes that have been proposed by recent studies.

* as of 31 December 2024