Breeding plumage above, winter plumage bottom. Birds in eastern Asia including Japan are the race T. r. poggei which have distinctive pale lemon yellow eyes as seen here. Other subspecies have dark reddish or red-brown eyes. This smallest Eurasian grebe is sometimes called the Dabchick. This species may be divided into two groups with darker-bellied birds birds in New Guinea and surrounding islands sometimes split as "Tricolored Grebe." Canon PowerShot SX60
Reference:
Brazil, M.A. (1991) The Birds of Japan. Smithsonian Inst. Press.
Llimona, F., del Hoyo, J., Christie, D.A., Jutglar, F., Garcia, E.F.J. & Kirwan, G.M. (2019). Little Grebe (Tachybaptus ruficollis). 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/52477 on 1 April 2019).