The December update on UV described his near desertion of the northern part of the Langue de Barbarie. That is still an accurate description of his behaviour; unless he has visited for very short periods when the fixes are every 30 minutes or so he hasn’t perched there since 4 January. On that day he was flying more often than normal over water and mainly at foraging height. This image shows his various outings which were all during the afternoon.
As you can see he concentrated on the river rather than travel offshore. During the yellow trip with the 14.14 fix he was recorded at heights around 100m but otherwise he tended to be at about 45m ASL.
The rough sea conditions mentioned in the last post are likely to be affecting UV’s behaviour. The wind is still usually from onshore which will lead to higher waves and recently there has also been an influence from the ocean swell created by a very active low pressure area to the west. Here is a graphic of it courtesy of Paul.
UV does still fly offshore but whether he catches fish is debatable. He is showing more interest in the southern part of the Langue, the National Park, that was his territory until October and his ocean flying is normally west of there or just beyond the breach which separates the two parts of the Langue. The next image shows UV flying offshore as he headed north and crossing the spit quite near his old ‘home’.
UV was generally too high to have been foraging. He appears to be checking out the National Park more often; on 12 January he spent much of the afternoon just to the south of the land shown above.
Is he gaining more confidence in holding his own in an area with many adult Ospreys? Spring migration for adult Ospreys won’t begin until late next month so it will be interesting to see if before then UV spends increasing amounts of time in the National Park.
UV’s behaviour may also reflect an alteration to his non-ocean foraging. The fix above ‘Mboumbaye’ was early morning and on other days this month he has been over the channel then returned to near his roost for several hours, presumably with breakfast in his talons! Fixes early in the day are infrequent but UV used to fly at around sunrise to the north part of the Langue along the channel, rather than return to the land near his roost. He may have had breakfast with him then too, but spending more time inland is a change in his day. Perhaps the channel alongside the National Park is now his principal source of fish rather than one of several areas.
UV’s main perching area during the day is in and around the outflow from Lake Guembeul, although he is still flying NE to the Ngalam River area occasionally. Especially during these trips he is at altitudes of over 300m ASL much of the time and up to 1000m or so. This graphic by Paul shows how far he can see on a clear day – and he has had many recently.
To the south the part of the Grande Côte he lived in when first in Senegal is just a few km from his field of view. To the north Djoudj National Bird Sanctuary, on the UNESCO World Heritage List, and to the east Lac de Guiers might seem attractive to UV. Ospreys overwinter at both but UV doesn’t seem tempted. Will he explore further afield soon?!