FLASH! UV is in Western Sahara

The last post mentioned that no other UK osprey was known to have had a longer stopover than either UV or 7H, which was perhaps an indication that they would overwinter in Portugal and Morocco respectively.

Well, by mid afternoon today, 10 December, UV was flying SSW over Western Sahara. And travelling at pace.

Most of the data is missing for his journey. On Sunday the last fix showed him about 14 km off the SW tip of Portugal. He had gone out to sea about 100 km further north, so it did look as if he might be moving on.

There has been no data since then until this afternoon, and given his location we are lucky to have received the very limited download that came in. Here is an image of the gap!

A large gap in data between 7-10 December

A large gap in data between 7-10 December

And here is a closer view of the travel today between 12.50 and 15.17.

UV during just over 2 hours today

UV during just over 2 hours today

Paul Wildlifewriter (to whom my personal thanks for keeping me as sane as possible during a worrying time) has provided daily weather information. The winds have been mainly NNE during his onward migration, so roughly tailwind. There was a clear night and the moon was just past full on Sunday, which must have been spent over the sea. (No ships appeared to be in the area!)

Hopefully more data will backfill when he reaches cell towers again. Which could be quite a while.

Paul also noted that yesterday there was a diurnal sandstorm on the coast of Mauritania: satellite imagery showed the dust being blown out to sea. Fortunately that has now subsided and UV was about 500 km away at last fix. He was flying strongly during the data window, speeds at up to 66 kph, and at altitudes up to just short of 1000m.

Since Sunday he has travelled at least 1570 km – that is the straight line measurement. He is about 900 km from the Mauritania-Senegal border. The winds will be less favourable tomorrow, more easterly and fresher. Paul has estimated that if he maintains today’s heading and with the wind direction he could arrive at the Banc d’Arguin, a UNESCO World Heritage Centre and migration hot spot.

Keen osprey followers will be aware that UV’s route is probably quite similar to those of Millie, the 2014 Loch Garten juvenile currently wintering on the Mauritania-Senegal border, and Alba, a 2012 juvenile from that nest. How similar can only be determined if the missing data is backfilled.

Tomorrow there will be a post with a bit more about UV’s time in Portugal. Which is now the record for a stopover for a UK osprey, as far as is known.


This entry was posted in Blue UV, Migration, Osprey updates and tagged , . Bookmark the permalink.

5 Responses to FLASH! UV is in Western Sahara

  1. I reckon he needed the long rest to store up energy for another stage of the journey. Thanks for the update.

  2. JOyce Rawlings says:


  3. KEITH ROGERS says:

    Many Thanks – Joanna – I think many of us have been waiting sometime now for this blog that he has moved on to Africa. One wonders why he stopped over so long then triggers this move – although we have learnt very much from ospreys travels I doubt if we will ever get the answer to this.
    We all wish him well on his travels wherever he settles – he needs to ascert his authority wherever he settles as he probably will meet a few neighbours.

  4. Vivien Finn says:

    Many thanks for this update, Joanna. Excellent news that UV has made it to Western Sahara and is flying strongly and at some pace. Everything crossed for his safe arrival on good fishing grounds. Hopefully maybe where Paul has indicated. Very much looking forward to your next posting, and thank you both for all the information given.

  5. The manner of UV’s departure from Portugal highlights one of the most intriguing – and mysterious – aspects of bird migration. To all outward appearances, it was just a “normal” day. In the morning, UV visited three of his favourite perching sites, toured over the reservoir for an hour or so and then, at 11:00 UTC said to himself “Today, I think I’ll fly 1000km to Africa.” What prompted this move? What was different about that day? Nothing obvious that can be deducted from any analysis. We have absolutely no idea.

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