On Saturday morning, whilst I was potting around in the garden, I heard a very distinctive call from a flock of birds. At first, I couldn't see the birds but about a minute later, I saw 3 brown birds with whitish head and breast perching on the branch of the red bottlebrush tree (Callistemon viminalis) which is growing as a wayside tree outside my place. At the time, I didn't know what it was but after searching on the internet and my brand new 'New Holland Field Guide to the Birds of Southeast Asia', I came to know that the birds I saw were the White-Crested Laughing Thrush (Garrulax leucolophus).
Apparently these are fairly common in Singapore and it's range extends across South-East Asia right up to Mynanmar. Quite a few people in SIngapore have blogged about it and The NSS' Bird Ecology Study Group has quite a few write-ups about this species. These can be found here here .
One of the most distinctive features of this bird is, as its namesake suggest, is it's laugh. I managed to find a very good clip on youtube showing the distinctive call.