There are several races that have been noted, race travancoreensis is found in the Western Ghats south of Goa and is darker (see Gloger's rule). The nominate horsfieldii is found in the plains in the southern part of the peninsula. The race obscurus of the dry zone in the northwest (Madhya Pradesh, Rajasthan and Gujarat; possibly Orissa) is lighter and greyer. Race maderaspatensis of the Eastern Ghats is intermediate in plumage between the nominate form and obscurus. Race maderaspatensis lacks the black base to the upper mandible and the bill is shorter. It has been recorded from the Palkonda Hills, Nallamalai Hills, Kurumbapatti and Shevaroy Hills.