Their breeding habitat is rivers in primary forest in the southeastern Russian Far East, perhaps in North Korea, and in two locations Changbai Mountains and small isolated location in Lesser Xingan Mnts. in northeastern China. The bulk of the species' population breed in Russian Far East (85%) and Changbaishan both in China and DPRK M. squamatus are migratory, wintering in central and southern China, with small numbers in Japan, South Korea, Taiwan, northern Vietnam, Myanmar and Thailand. They arrive on the breeding grounds as soon as winter is over, in March, and leave when the first cold nights come in mid November.