As a keen Holarctic lister, I long regretted the absence of a fully up-to-date checklist of bird species regularly occurring in the Palearctic and Nearctic regions. I sought an easily referenced record of recent and potential taxonomic changes, also taking into account improvements in distributional knowledge (particularly in Mexico and Himalaya). Consequently over several years I developed and maintained a working checklist as the core of my personal records database. I have posted it on this website in the hope that it may be a useful resource for other birders with similar interests.
The checklists maintained by regional and national recording authorities are (necessarily) rigorous and conservative. My approach has been more liberal - implementing all splits adopted by at least one relevant authority (but with clear indication of the recognising authorities), and identifying potential splits even where rather questionable. It is intended for use by recreational birders, motivated to seek interesting forms of each species.
Comments, corrections and additions welcome.
Richard Klim
Somerset, UK