Although the UK400 club is primarily concerned with birding in Britain and Ireland, they do also provide a Western Palearctic base-list. Whilst the UK400 club is not an official body, its base-list for the region is kept up to date, although its taxonomic decisions are not fully documented. As with the UK400 list for Britain & Ireland, this base-list takes a more liberal approach to splitting and potential escapes than does the AERC. It is assumed that the UK400 club's Western Palearctic list refers to the same geographical area as that of the AERC, i.e. the area used by Birds of the Western Palearctic.
The list used by BUBO Listing for this authority is that published in January 2008. Some of the updates in this version of the list involve splitting existing species, including Cape Verde Storm Petrel Oceanodroma jabejabe, American Sandwich Tern Sterna acuflavida, Long-billed Crested Lark Galerida macrorhyncha, Gran Canaria Blue Tit Cyanistes hedwigii, Egyptian Nile Swallow Hirundo savignii, North American Barn Swallow Hirundo erythrogaster, Egyptian Yellow Wagtail Motacilla pygmae, African/Arabian Scrub Warbler Scotocerca saharae/inquieta, Madeiran Chaffinch Fringilla madeirensis, Asian/African Crimson-winged Finch Rhodopechys sanguineus/alienus. In addition, Indian Pond Heron Ardeola grayii, Common Babbler Turdoides caudatus and Purple Sunbird Nectarinia asiatica have been added, in addition to several introduced species, whilst Roseate Spoonbill Ajaia ajaja has been removed.
Dec 2009 - Desert Grey Shrike (Lanius elegans) added
Feb 2011 - Slaty-backed Gull (Larus schistisagus) added
Species currently considered as comprising the UK400 Western Palearctic List for BUBO Listing purposes are shown below.