Study of summer-autumn migration of sandpipers, including spoon-billed sandpiper in Kamchatka

The East Asian–Australasian flyway used by the rarest spoon-billed sandpiper stretches from Alaska and Chukotka in the north to Australia and New Zealand in the south. Western coast of Kamchatka with its numerous estuaries and high tides is known for its migratory clusters of shorebirds. But the majority of sites, including those where sandpiper stops, are still not studied or studied very poorly. Kamchatka branch of BirdsRussia undertook collection of information in one of such places — estuary of Bolshay Vorovskaya river. It is located in the central part of the western coast of the peninsula and it stretches for 40 km and is up to 1,5 km wide. During the low tide extensive sand and mud banks are exposed where numerous sandpiper flocks rest and feed. We thoroughly studied southern 5 km part of estuary between the mouth of the river and Ustiev village. 

The works were carried out in July-September 2014-2018. 172 counts of shorebirds that feed on the estuary at low tide were carried out. Spoon-billed sandpipers were given special attention. We used the received data to confirm the status of the estuary as a stopping place for shorebirds during migration, which is of international importance according to the standard criteria established by the Ramsar Convention and additional criteria adopted for spoon-billed sandpipers on the East Asian-Australasian flightway. It is important for protection of spoon-billed sandpiper as well as other species. That is what we used.  

In five years of research we registered 36 shorebird species, the maximum in one count being 12,000 birds in 2014, 17,080 in 2015, 10,530 in 2016, 70310 in 2017 and 14430 in 2018. Spoon-billed sandpipers, that were the subject of our special interest, fed on the muddy littoral area from August until the middle of September, and in the first and second decade of August we met them almost daily. Encountering spoon-billed sandpiper, even one bird, allows to attribute to the area the status of international importance, but besides them Bolshaya Vorovskaya river estuary was attributed international status for eight more species. These are lesser sand plover (10% of all the population, migrating through this flyway); whimbrel (2,3%); red-necked stint (1,4%); dunlin (1%); black-tailed godwit (0,8%), great knot (0,8%) and turnstone (0,6). 

Impressive results were brought by the observations of shorebird flocks flying by. At least 32 thousands whimbrels fly through this area, 28 thousands of which we counted in one day: half of all the whimbrel population of East Asian-Australasian flyway flew above us in just five evening hours!