The juvenile American Golden Plover (Pluvialis dominica) shown here is the third example of this neartic vagrant I have observed on La Palma this autumn. The two previous birds were both discovered in freshwater irrigation basins in Las Martelas, and one of them is still to be found there at the time of writing.
This third example, however, was seen feeding at the seawater pools opposite the airport, on the east coast of the island, on Nov 6. The relevant plumage details can be clearly appreciated in this series of images, and identification and distribution of this long-distance migrant have been briefly covered in previous posts.
It is perhaps interesting to reflect that P. dominica was not separated from P. fulva until relatively recent times. Present-day populations of the former are estimated at 10,000-50,000 individuals, despite heavy hunting in the past. The post-breeding migration route is typically an ellipse, in which the outward journey from the arctic and subarctic tundra of North America initially follows the east coast of Canada southwards, crosses the Caribbean, and eventually reaches wintering quarters in Argentina, with the return journey being routed further to the west.
Most remarkably, it appears that the leg from Canada to South America is covered in a single non-stop flight, which, in fair weather, is estimated to take 37 hours. Hardly surprising then, that vagrants turn up in Europe, and other parts of the world, fairly frequently!
Up to 2003, only 28 records of dominica in Spain had been accepted by the Spanish Rarities Committee: 12 in the Canary Islands, and the remaining 16 on the mainland.
The above information has been taken from Aves Raras de España (Eduardo de Juana, Lynx Editions, 2006), a catalogue of bird species of occasional occurrence in Spain. The book includes a table of all records accepted by the Spanish Rarities Committee up to the year 2003.
viernes, 12 de noviembre de 2010
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