Black-crowned Night Heron

Description:

Rather stocky-looking birds. Red eyes. Dark patch on head. Dark wings. Front is white.

Habitat:

These birds are not captive although they live inside the Kolkata zoo. They live on islands inside the zoo and share the open-air enclosures of some animals such as the crocodiles. Maybe because there is water there.

Notes:

The last one is likely a sub-adult. These birds nest on trees in even very crowded urban areas of Kolkata.