The male Rufous-backed Marsh Hawk (Brachydiplax chalybea) has a striking blue and orange thorax, backed by a blue abdomen with black segments towards the end. 
This species is widespread in Singapore and can be seen at most ponds, pools and lakes that have tall reeds at the edge. 
They are easily frightened and fly away at the slightest thing. 
Oddly enough, even though the male is very common, the female is not so. 
The brown female is seldom seen because she often hides away in the trees and only comes down to the water's edge briefly.

The male Brachydiplax chalybea looks rather similar to the male Aethriamanta gracilis and male Brachydiplax farinosa which also occur in Singapore.
Aethriamanta gracilis is also very common in Singapore but Brachydiplax farinosa is very rare.
Brachydiplax chalybea is generally easy to identify because the side of its thorax shows a lot of orange.
Aethriamanta gracilis can be distinguished from the two Brachydiplax species by its entirely dark brownish eyes whereas the two Brachydiplax species have two-coloured eyes.

Sungei Buloh Wetland Reserve, Singapore, 25 October 2022