The book: Birds of Singapore by Christopher Hails, Frank Jarvis.
The bird activities will be at its peak 1 hour after dawn, which is around 8am in Singapore, and it will become quieter from 11am to 4pm, after which activities resume for their last morsel before resting the night.
Breeding seasons will be from February to July for the resident species, and Singapore willbe playing host to the migrants from the month of Spetember till April.
It is stated that it would not matter that one wears bright colours for bird-watching since the birds would be able to see you from afar, having trained its eyes for the minute details of an insect or lizard. As long as it is not threaten or not very shy, it will remain in its position until it has spotted something else.
C.Hails, F.Jarvis, Birds of Singapore, 1987.