The Red Junglefowl (Gallus gallus) is the wild ancestor of the domesticated chicken.
It is a common resident in secondary forests, scrub and parks in Singapore.
It looks very similar to the domestic chicken and care is needed to distinguish wild birds from these and hybrids.
However, there are several noticeable differences between a Red Junglefowl and a domestic chicken. 
A male Red Junglefowl has two obvious white patches on its body – below its eyes and at its rump, near its tail. 
It also has grey legs, while a domestic rooster has yellow or pink ones.

1st, 2nd & 3rd photo: Pasir Ris Park, Singapore, 24 October 2022
4th photo: Bukit Batok Nature Park, Singapore, 23 October 2022
5th photo: Singapore Botanic Gardens, Singapore, 7 November 2022