Female above, male below. Females closely resemble female House Sparrows. Thirteen subspecies have been described but only three are usually recognized. Birds in Japan are the paler P. c. rutilans characterized by grayish-white underparts, lacking any creamy yellow coloration. This species formerly went under the name Passer rutilans but Mlíkovský argued persuasively that the correct name for this species should be Passer cinnamomeus (Gould, 1836) on the basis of priority. This change has now been widely accepted. This species sometimes goes by the English name "Cinnamon Sparrow." 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.
Mlíkovský, Jirí. (2011). Correct name for the Asian Russet Sparrow. Chinese Birds 2(2):109-110. doi:10.5122/cbirds.2011.0016.
Rasmussen, P.C. & Anderton, J.C. (2012) Birds of South Asia. The Ripley Guide. Vols. 1 and 2. Second Edition. Smithsonian Institution. Michigan State University & Lynx Edicions, Washington. D.C., Michigan & Barcelona.
Summers-Smith, D. (2019). Russet Sparrow (Passer cinnamomeus). 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/60930 on 4 May 2019).