"Cotigao is the smallest sanctuary in Goa, but it's got some of the best forests," says Paresh Parab, the sanctuary ranger, enthusiastically, as we walk through the multi-storeyed forests of this sanctuary, on the southeastern fringe of Goa. A pied hornbill flies through the canopy, its distinctive beak outlined in the light. Through the corner of my eye I catch a fleeting glimpse of the rust-brown shape of a giant flying squirrel, as it flows down one branch, across a gap, onto the next tree. As we leave, I stop to listen to a bewildering array of raucous cries. "That's the racket-tailed drongo," whispers Paresh, "they're excellent mimics".