This species was formerly known as the Nutmeg Mannikin until the AOS changed it in 2014. They were introduced in Hawaii in 1866 and are now well established in all the main islands. Their natural range goes from South and South-East Asia to Indonesia and the Philippines. The subspecies introduced in Hawaii appears to be L. p. topela of Southern China and Southeast Asia. This race is characterized by being duller brown above with plain olive-brown tail and having relatively faint double scaling on the underparts. This scaling extends up to the lower throat in this race as seen here. Juveniles (bottom two images) are similar to juvenile Chestnut Munia, but distinguished by Scaly-breasted's black rather than bluish bill. Canon PowerShot SX60 HS.
References:
Clement, P., A. Harris, and J. Davis. 1993. Finches and Sparrows: An Identification Guide. Princeton Univ. Press, Princeton, N. J.
Payne, R. (2020). Scaly-breasted Munia (Lonchura punctulata). 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/61187 on 28 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/