sábado, 18 de noviembre de 2017

Migratory Osprey (Pandion haliaetus)

Route taken by Osprey 637 around the island of La Palma, and on towards La Gomera 
(image: Forestry Commission Scotland)

Two weeks ago, I was very kindly contacted by Janet Sampson, a British observer, who had been following the migration routes taken by several juvenile Ospreys (Pandion haliaetus) released in Scotland. On Oct 28, one of the birds, nº 637 had reached the island of La Palma, after a very "oceanic" flight south. In Janet's words:

"The route taken by this juvenile (osprey 637 on the tracking map) is very interesting as he/she took a very westerly route from Portugal, perhaps due to the prevailing winds yesterday.  637 made a stopover of a few weeks at the Embalse de Tanes, Abantro in Northern Spain and only left there 5 days ago on 23 October".

Details of the project, and regular updates of 637's position can be found at the following link:


After receiving the alert on Oct 28, I spent the whole morning of Oct 29 searching for 637 in the northeast of La Palma. The bird had spent the night in the vicinity of San Andrés, and I was hoping to locate it somewhere along the sea cliffs between Playa de Nogales and Barlovento. However, my search turned out to be fruitless.

Movements of 637 on La Gomera over the last two weeks
(image: Forestry Commission Scotland)

637 seemed to be firmly intent on reaching the coasts of La Gomera, where he/she has been for the past fortnight. Recently, the bird ventured out to sea and back, and made some incursions inland, its flight paths clearly visible in the above screenshot.

The island of La Gomera boasts a small breeding population of Ospreys, which has remained more or less stable over recent decades at around 3-4 pairs. The main threat to the species is human encroachment on potential habitat.

The Osprey no longer breeds on La Palma, although it is presumed to have done so in the past. Remains of old nests have been identified, and the island's toponymy includes several references to "guincho" the Canary Island name for the bird known elsewhere in Spain as the "Fishing Eagle", Águila pescadora.

However, migratory Ospreys continue to visit La Palma, and I have seen several here over the years. Some of the island's man-made irrigation ponds have been stocked with carp and/or goldfish, which provide a convenient and relatively easy-to-catch source of nourishment for these resourceful birds.

As in other parts of its worldwide range, the Osprey (Pandion haliaetus) seems able to adapt to humanised surroundings, provided it perceives no direct threat. Many of the irrigation ponds on La Palma are found in semi-urban areas, in which electricity pylons and telephone posts make useful perches:

Osprey (Pandion haliaetus) perched on a telephone pole on La Palma, 30/03/2012

The occasional presence of a migratory Osprey on La Palma soon attracts the attention of resident gulls and raptors such as the Kestrel (Falco tinnunculus).

Migratory Osprey being harassed by a Yellow-legged Gull (Larus michahellis). La Palma, 28/03/2012

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