This ancestor of the domestic chicken was introduced in Hawaii by early Polynesian settlers around 500AD where it survives only on Kauai. Populations on other islands were eradicated, apparently by introduced Mongooses. These birds interbreed readily with domestic chickens but my understanding is that birds such as this male with gray (not yellow) legs is representative of the original ancestral type. The subspecies introduced in Hawaii is probably the Javan Red Junglefowl (G. g. bankiva) characterized by redder hackles with rounded feather tips as well as an exaggerated larger comb and throat wattle cf. other subspecies. G. g. bankiva also has a reduced white ear wattle. Genetic evidence suggests that the majority of Red Junglefowl on Kawai are of hybrid origin often showing white feathers indicating domestic chicken ancestry. However this individual does not show any obvious white feathering and appears reasonably close to the ancestral type. Canon PowerShot SX60 HS.
References:
Callaway, E. (2016) When Chickens go Wild. Nature 529(7586):270-273 DOI: 10.1038/529270a
McGowan, P.J.K. & Kirwan, G.M. (2020). Red Junglefowl (Gallus gallus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53485 on 25 January 2020).
Pratt, H.D., Bruner, P., and Berrett, D.G. (1987) A Field Guide to the Birds of Hawaii and the Tropical Pacific. Princeton University Press.
Pyle, R.L., and P. Pyle. 2017. The Birds of the Hawaiian Islands: Occurrence, History, Distribution, and Status. B.P. Bishop Museum, Honolulu, HI, U.S.A. Version 2 (1 January 2017) http://hbs.bishopmuseum.org/birds/rlp-monograph/