A very rare bird to find in the wild indeed. most birders will go goo-gah on seeing one. Very hard to find in Singapore because of extensive habitat loss... how many mangroves have we got left? You can try finding them in a few places...
1. sungei buloh nature park
2. chek jawa mangrove
More chances to find the bird in Malaysia where the mangrove is denser and more healthy.
Good luck.