Every autumn, thousands of arctic-breeding waders pass through the UK en route to their wintering grounds, stopping to fuel up before continuing further south. Among the ubiquitous Dunlin may be a subtly different bird - a Curlew Sandpiper.
Curlew Sandpiper or Dunlin?
Curlew Sandpipers are one of the most attractive waders to occur in the UK and with a little practice, they can be easily picked out. They are usually found among flocks of Dunlin and so direct comparisons between the two species can be made.
Curlew Sandpipers appear more elegant than Dunlin with a more upright stance, due to their longer legs and more elongated neck. Their longer legs also allow them to wade into deeper water than Dunlin. In flight the rump of a Curlew Sandpiper is white, which contrasts well against the dark rump of the Dunlin. Curlew Sandpipers have longer, more decurved bills than Dunlin and slightly longer wings which add to their more elegant profile. Juveniles show a peachy flush to the breast and striking white supercillium above the eye.
In spring the difference between the two species is very striking with the brick red underparts of a Curlew Sandpiper standing out from the more drab black belly of the Dunlin, and this is still apparent on returning adults in autumn, but juvenile birds are much more similar.
Curlew Sandpiper breeds on the tundra of Arctic Siberia and is strongly migratory, wintering mainly in Africa, but also in south and southeast Asia and in Australasia, travelling a distance of over 15,000km.
In the UK, monthly counts carried out for the Wetland Bird Survey (WeBS) can be a useful barometer of the breeding season for arctic nesting birds as many juvenile birds pass our shores.
The autumn of 2012 was a relatively poor one with a high count of 23 on The Wash compared with that of 1998 when 143 were counted on the North Norfolk Coast. Take a look at our WeBS report for Curlew Sandpiper.
The number of Curlew Sandpiper turning up on our coasts are largely dependent on the summer's breeding productivity and the weather conditions during migration.
The numbers of Curlew Sandpiper passing through Britain pales into insignificance however compared with the numbers passing through the near continent, with the German part of the Wadden Sea hosting up to 27,000 birds.
When to see Curlew Sandpiper
With migration now in full swing, a visit to a coastal marsh in August through to September should provide you with the opportunity to pick out one of these birds, though small numbers do turn up at inland sites too.
Juvenile birds lacking the brick red of the adults are most likely to be confused with the more abundant Dunlin but once you get your eye in, you will be surprised how much they stand out from the crowd.More BirdFacts for this species
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