The colourful barbets are closely related to woodpeckers. They are as common in the gardens of Delhi as they are in the wooded streets of South Mumbai.
Many believe that the typical calls repeated rhythmically is an indicator that our city pollution levels are still under control in many parts which have large trees around.
In common with woodpeckers barbets feet have two toes facing forwards and two back. This feature allows them to cling easily to trees and excavate their nests.
The place to look for them in Mumbai is old fig trees. In Delhi, the coppersmith and green barbet are regular garden visitors (mostly in large public gardens).
The short video below on the “feathered heritage of India” opens with a coppersmith calling and excavating its nest on a dead tree trunk in a common park in a residential area in Delhi.
India's Feathered Heritage - These bloopers are hilarious
The photos below are of a green barbet guarding its chicks inside the tree hole nearby. Curious onlookers are still there, like the mynah, which is trying to peer in and of course my camera!