The nominate race C. s. splendens is found in Pakistan, India, Nepal and Bangladesh and has a grey neck collar. The subspecies C. s. zugmayeri is found in the dry parts of South Asia and Iran and has a very pale neck collar. The subspecies C. s. protegatus is found in southern India, the Maldives (sometimes separated as maledivicus) and Sri Lanka and is darker grey. C. s. insolens, found in Myanmar, is the darkest form and lacks the grey collar.Rasmussen, PC & JC Anderton (2005) Birds of South Asia: The Ripley Guide. Smithsonian Institution and Lynx Edicions. Vol 2. p.598
