I managed to process one more photo from my last visit to the ZOO. There are many birds that live freely on the ZOO area and this duck is one of them. Few words about it:
The Ruddy Shelduck (Tadorna ferruginea) is a member of the duck, goose and swan family Anatidae. It is in the shelduck subfamily Tadorninae. In India it is known as the Brahminy Duck.
There are very small resident populations of this species in north west Africa and Ethiopia, but the main breeding area of this species is from southeast Europe across central Asia to Southeast Asia. These birds are mostly migratory, wintering in the Indian Subcontinent. This is a bird of open country, and it will breed on cliffs, in burrows, tree holes or crevices distant from water, laying 6-16 creamy-white eggs, incubated for 30 days. The Ruddy Shelduck is usually found in pairs or small groups and rarely forms large flocks. However, moulting and wintering gatherings on chosen lakes or slow rivers can be very large.