Waterhen ( Ruak-ruak ) in Malaysia

White-breasted waterhen ( Ruak-ruak ) ( Amaurornis phoenicurus ) is the only species of the genus Amaurornis found in Malaysia.
 
Local names of this bird are often formed by onomatopoeia (based on the sound it makes), thus “ruak-ruak” in Malay.
 

Amaurornis  contains 5 species:
● Isabelline bush-hen (Amaurornis isabellina) - Sulawesi
● Plain bush-hen or Philippine bush-hen (Amaurornis olivacea) – Philippines
● Pale-vented bush-hen (Amaurornis moluccana) – Indonesia, Papua New Guinea, Australia, Solomon
● Talaud bush-hen (Amaurornis magnirostris) – Talaud Islands
● White-breasted waterhen (Amaurornis phoenicurus) – South Asia, SE Asia
 
 
Several subspecies are named for the populations that are widely distributed :
● A. p. phoenicurus ( chinensis ) – South Asia, SE Asia
● A. p. maldivus – Maldives
● A. p. insularis – Adaman, Nicobar
● A. p. leucocephalus – Nicobar
● A. p. midnicobaricus – Nicobar
● A. p leucomelana – Sulawesi
● A. p. variabilis – Sualwesi