Bird Checklists of the World is part of Avibase and Bird links to the World, which are designed and maintained by Denis Lepage, and hosted by Bird Studies Canada, which is a co-partner of Birdlife International.
I have doubt to be cleared please. Do this checklist include only the reported and observed species or does it include the species that might occur due to geographical similarity with the other regions as well?
I think Tsering Sir, this list is based on the global database, so we need to cross-check for actual record/observation. May be you can contact Mr. Sherab of UWICE and this is the exact reason why NBC has been proposing for curators meet to come out with actual national statistics for each taxonomic group. It is so confusing for people to see so many different versions of stats but nevertheless, it gives baseline for us to authenticate. Hope one day soon the curators meet will materialize and we would be able to share the national stats on biodiversity!