After breeding, move south for boreal winter. Migrate by day & night, & most migration coastal ca. 100m from shore. Migrating flocks reported at various altitudes from ca. 15m to a few hundred feet.
Leave Kamchatka Peninsula from mid-July; weak migration through Ussuriland, Siberia, mid-July to late September. Pass through Kurile Islands & Sakhalin mid-July to late August. Fewer appear in continental Asia on southern migration than on northward migration. Common in Korea August & October. High numbers counted in Japan August to October.Transient central China & along coast to Hainan; over 2000 counted along coast on southern migration in Northeast China in 1992. Scarce passage migrant Hong Kong mid-September to end of November. Few reported Thailand,Malaya,Singapore & Philippines, though some have said that Olango Island Philippines is an important staging post.. Few records Sumatra,though several hundred birds October-December 1984 & count of thousands after 1988. In Borneo passage migrant from 17 August;in Wallacea October- November. Large numbers reported Timor. Usually arrive Port Moresby district New Guinea August with peak numbers in October. Occasionally stray to Fiji & rare but possibly regular in Micronesia.
Arrive Northwest and East as early as July, but maximum arrival mid-August to the end of August. Onward movement from northwest by October, 7 said to arrive at Northwest Cape by end of September. Uncommon passage migrant Torres Strait Islands mainly October onwards. Flocks observed out to sea from Darwin to Brisbane in third week of October. Most arriving in eastern Australia appear to move down the coast.; influxes occur on East coast September to November, & particularly laate August with counts suggesting general southern movement until mid-February. Records from Towoomba Queensland & Broken Hill far southwest NSW suggests some birds move overland. But arrivals along east & southeast coast suggests some fly directly to those areas. In Victoria most arrive November, with smaller numbers moving west along coast as early as August. In southern Tasmania, arrive third week of August to early October; also stragglers to December. When first arrive in Tasmania can found at many sites but later congregate at Ralphs Bay or Sorell.
Median date of arrival mid-October,ranging from second week of August to mid-November, with records in South as early as September.Numbers increase at some localities till mid-December.
Extralimitally, during non-breeding period, small numbers in south Korea, Japan,China,Taiwan, Indonesia & occasionally New Guinea, Borneo, Malaya & Philippines. In Australia, mostly at small numbers of sites on east & south coasts & northwest. Numbers stable at most sites November or December to February. Move locally between high-tide roost site & intertidal feeding zone.
In Australia, most leave late February to late March, though in 1985, numbers decreased steadily till last week of April.
Leave Tasmania March & April. In Victoria, one flock, apparently migrating, moved inland from March. Unknown if influxes of adults occur on east coast during migration; apparently overfly north coast. Numbers decrease at Raby bay in north Queensland during February. Said to be common at Kimberley northwestern Australia during March. No influx in Broome region., where flocks seen leaving mid-March. In New Zealand, median date of departure end of March, ranging from mid-March to mid-April in all localities. In some years increase noted in Auckland-North Auckland before departure.
Extralimitally, leave Port Moresby district in New Guinea usually in April, with numbers peaking in March. On passage in Wallacea April-May. One record of a few hundred in Sumatra March-April 1986. In Japan, fewer occur than in southward migration; on Kyushu Island, birds leave from mid-March; at Kobdo, first birds 26 March with main migration end of April. Uncommon passage migrant Hong Kong 10 March to 12 May. Fly over China, where at some sites common on southward migration. Pass Korea and Ussuriland in April & May. Pass Kurile Islands & Sakhalin from mid-April to late May. Arrive Kamchatka during May.