Wintering in Casamance

In our last update we reported that Jules set-off across the vast wilds of the Sahara on 19th October. We now know that he completed his desert crossing just over three days later and is now settled in the Casamanace region of southern Senegal, 30 km WSW of where Blue DF is wintering.

Jules made a superb start to his desert crossing on 19th October, flying 519 km across the spectacular land forms of the north-west Sahara. He crossed the disputed border between Morocco and Western Sahara at 11:00 GMT and then maintained speeds of almost 50 kph during the afternoon, passing into Mauritanian airspace at 15:09 before settling to roost at sunset in remote north-west Mauritania. The Google Earth imagery suggests that Jules would have had to roost on the ground, and it seems that he was disturbed during the night because at 23:00 he took off again and flew 25 km south-west.

He moved a further 22 km south-west before dawn next morning and then resumed his migration at around 08:30. Conditions must have again been in his favour because he flew a further 423 km south-west during the course of the day before roosting close to the southern border between Western Sahara and Mauritania. Next morning he was away before dawn and flew 67 km south-west before pausing again at 08:06. After resting for an hour he resumed his journey and maintained a constant SSW heading for the rest of the day, covering a further 418 km across the Akchar and then Trarza desert regions. By the time he settled to roost at 19:00 he was within 100 km of the Senegal border having flown 485 km from his overnight roost and a total of 1474 km in just three days; a superb Saharan crossing.

Jules flew just under 1500 km across the Sahara in three days

On the morning of 22 October Jules set-off at first light and shortly after 09:30 he reached the Senegal River; his first sight of water for at least four days. Many European ospreys winter in this northern part of Senegal but Jules showed no signs of letting up. After crossing the river just to the west of Richard Toll he headed south along the eastern shore of Lac de Guiers and then onward across the arid north of Senegal. At 16:34 he reached the Atlantic coast at the northern edge of the vast Sine-Saloum delta. He continued flying for a further two hours before settling to roost in one of a myriad of mangrove-lined creeks in the delta, 7 km north-west of the village of Missirah; a place both Roy and I have visited several times.  Having flown 461 km from southern Mauritania, it had been another excellent day’s migration.

Sunset at the Sine-Saloum delta (photo by John Wright)

Jules obviously sensed that he was now close to his winter home because he set-off before first light next morning and at 07:22 was 25 km further south on the north bank of the River Gambia. He was then perched for an hour, perhaps eating a fish, before continuing south across the river and then back in to Senegal at around 11:00. Once in Senegalese airspace he turned to the south-west and flew directly over Blue DF’s wintering site at 13:00 – they would almost certainly have seen each other – before heading another 30 km west and eventually settling in a mangrove- lined creek on the north side of the Casamance River, having flown 153 km during the  course of the day. He was now very close to where another of our satellite-tagged ospreys, Blue XD used to winter.

Jules (pink line) flew directly over the area where Blue DF (blue) is wintering – they would almost certainly have seen each other

After arriving in Casamance on the afternoon of 23rd October Jules has roosted in the same location every night, but, interestingly, has made almost daily flights to the coast near Boko in an area of 75 km² – far larger than the usual wintering range of most adult ospreys. It will be fascinating to see if he continues in the same vein over the coming weeks. Whatever the case, we can now be certain that he has reached his winter home.

Since arriving in Casamance on 23 October, Jules has made daily flights to the coast

Jules and Blue DF are wintering just 30 km apart in Casamance

Now that Jules has arrived at his wintering site we know that he flew a total of 5717 km during 17 travelling days. His overall migration, however, took 40 days to complete because he spent 23 days on stop-overs in France and Morocco. This migration strategy contrasts greatly with that of Blue DF who migrated  5494 km in 19 days without stop-overs. A summary of Jules’ flight from Scotland to Senegal is shown below. You can also check out his route on our interactive map.

Migration tracks for Jules (pink) and Blue DF (blue)