AW settled in the Ivory Coast
As we expected, the latest satellite data shows that AW has remained on a short section of the River Lobo in central-western Ivory Coast.
Over the past week he has ranged along a six mile stretch of the river and used three different roost sites, each a few miles apart. He is fishing in the river once or twice each day. Although the satellite imagery is poor, it is really interesting that the area he has now settled in is completely different to the spot on the Guinea coast where he spent over three months. He is now on the edge of a vast area of tropical forest known as the Western Guinean lowland forest which extends west into Liberia and south-eastern Guinea. From the satellite imagery it looks as if AW is in a slightly more open area more typical of the habitat that lies to the east. According to Wikipedia, the Guineana forest-savanna mosaic belt extends across the middle of the Ivory Coast and is the transition zone between the coastal forests and the interior savannas. One thing is for sure, it is very different from Rutland Water!
AW's roost sites beside the River Lobo
AW has Christmas in the Ivory Coast
I didn’t think I would be eagerly checking the satellite data on Christmas Day to find out where one of our birds has ended up, but that’s exactly what I’ve just done. Having spent the night of the 19th December in northern Liberia, AW has flown another 210 miles further east and is now in the central part of the Ivory Coast! For an adult Osprey to suddenly make this kind of move in the middle of winter is completey unprecedented, but it does suggest that the time he spent on the coast of Guinea was just an extended stop-over and that the Ivory Coast is his true wintering site.
So how did he get there? On the morning of 20th December AW began migrating again just before 10am. He continued flying for the rest of the day, maintaining a constant easterly heading at speeds of between 30 and 40kph at altitudes of between 500 and 1000 metres. By 5pm he had covered 207km and was perched beside a river – probably eating a fish – in the very western part of the Ivory Coast. He roosted in forest nearby. Next morning he was away again before 10am and again heading east-south-east. By 11am he had covered 36 kilometres and now changed to a more south-easterly course, heading towards the vast Lac de Buyo. By 1pm he was at the northern end of the lake and for the rest of the afternoon he zig-zagged the upper reaches of the lake, covering some 45 kilometres in the process. This was strange behaviour and suggests he may either have been interacting with other Ospreys, or simply unsure of where to go. He eventually settled to roost on the eatsern side of the lake, having covered 139km during the course of the day.
AW's movements around Lac de Buyo, 21st December
Next morning AW was back at the lake soon after first light, presumably fishing. He was at the lake for a couple of hours but by 10am he was migrating again, heading due east. An hour later he was perched beside the Lobo River river in a forested area some 20km to the east. Interestingly, he then flew no further. Over the course of the next 48 hours AW made only local movements to various different points along the river. Sadly, the satellite imagery of this part of the Ivory Coast is poor, but AW’s behaviour suggests that there is plenty of food in the river. The fact he remained in the same area for two days suggests that this may well be his usual wintering site. If he hasn’t moved by the time the next batch of data comes in then we can probably assume that this is the case. He is now 975 kilometres from the spot on the Guinea coast where he spent over three months. This is a quite incredible movement and shows that just when you think you know everything there is to know about Ospreys on their wintering grounds, one does something competely new and unexpected.
AW's movements in central-east Ivory coast 22-24 December
AW's flight from Guinea to the Ivory Coast
AW flies to Liberia, and maybe beyond!
AW's flight to Liberia, 17th-20th December
So what is going on? Well, here is what we know from the current batch of data. At 10am on the morning of 17th December AW was perched on the beach in his usual area, probably eating a fish. An hour later he had moved eight kilometres inland. Bearing in mind how little he had moved around for the previous few months, this in itself was a notable change from the norm; but nothing compared to what happened next. At midday, he was 13 km to the east, heading south-east at 30kph. Perhaps he was seeing off another Osprey? That obviously wasn’t the case though because an hour later he was another 27km further on and still maintaining the same course. This was more like migration! And that’s what he continued to do for the rest of the afternoon. By 5pm he was close to Conakry, the capital of Guinea having flown another 160km at a remarkably consistent speed along the coast. At 6pm he was perched either on the ground or in mangroves beside what on Google Earth looks to be a complex river delta system just to the south of Conakry. He was probably eating a fish; and no doubt there were plenty of other Ospreys around. He then roosted in mangroves 4km further south.
AW at Conakry
By 7am next morning AW was another 22km south-east, again perched among mangroves beside a river. He was still there an hour later but he must have resumed his journey soon afterwards. Although we are missing a series of data points, by 6pm he had flown another 180km south-east, and was resting close to a river in central Sierra Leone! Sadly the satellite imagery for this part of Africa is poor, but he appeared to roost in an area of scattered vegetation a couple of kilometres to the south. What was interesting was that he was now over 100km inland. Since leaving his regular spot on the coast the previous morning, he had maintained an incredibly direct south-easterly heading. It appeared that he knew exactly where he was going.
Next morning AW left his roost just after 9am and flew purposefully south-east for the rest of the day at altitudes of between 500 and 1200 metres. He crossed into Liberia in mid-afternoon and by 6pm, when he finally settled down to roost for the night, he had covered 280km. During his last two hours of flight he had changed his course to a more easterly heading. Whether this was an intentional change of direction or influenced by the weather, we are not sure, but we do know that he roosted close to the town of Basanai in northern Liberia. Again the satellite coverage of this part of Africa is very poor, but it looks to be a fairly densely forested area at an altitude of around 350metres. It is certainly not the kind of place you would expect an experienced adult Osprey to hang around so the chances are that AW will have continued his journey the next morning. His radio is currently on a five day duty cycle meaning we probably won’t receive any more data until Christmas Day. It will be absolutely fascinating to see where he is by then. Aside from his slight change of direction during the afternoon of the 20th, he had maintained a consistent south-easterly course for three days, suggesting he is heading for the Sierra Leone coast. Rest assured that we’ll update you as soon as the data comes in.
So what has prompted this sudden move? I rang Roy Dennis this afternoon and he was as stumped for an explanation as me. We have never recorded this kind of mid-winter movement by an adult Osprey before. It is possible, of course, that this is something that AW does every year. His southward migration was notable for a lack of stop-overs, but, in retrospect, perhaps that is all his time in Guinea was; an extended stop-over. Maybe his true wintering site lies elsewhere?
We haven’t yet updated Google Earth with this new data – but don’t worry, it will be done tomorrow morning.
An Easy Life
We’ve just updated the Google Earth tracking page. As you will see both AW and 09 are settled at their wintering sites in Guinea and Senegal. In fact the latest data really does demonstrate what an easy life adult Ospreys have in the winter. Both birds spend most of their time perched just inland, with one or two daily forays out to sea to fish. They usually catch within sight of land but on one notable occasion – on 19th November – AW was fishing six miles offshore. This reminded me of standing on the beach at Tanji in the The Gambia last winter and seeing numerous Ospreys fishing in the sea – and catching needle fish amongst others. Here’s a video we recorded that morning.
The migration facts
With 09 and AW both now settled on their wintering grounds, in Senegal and Guinea respectively, it has given us the opportunity to compare their flights to West Africa.
As you will know if you tracked their progress, the two birds followed a similar route as they flew south. Both birds crossed the English Channel at Dungeness and then flew south through central France, passing over Orleans and the Osprey nests situated close by.
As AW approached the Pyrenees he switched to a more south-westerly course to avoid the mountains, whereas 09 flew directly through the high peaks. Both birds then made good progress through Spain and, interestingly, we recorded the highest altitude for both birds on this section of their journey. 09 reached an altitude of 6112 feet as he migrated over Andalucia and AW flew south at an incredible 9055 feet just north of Madrid. Their flight paths then converged again in the south of Spain, with 09 crossing the Mediterranean at Tarifa and AW heading across the sea further east.
The migration routes of AW and 09
Once in Africa both birds skirted around the foreboding Atlas Mountains before following a remarkably similar route across the vast wilds of the Sahara. AW took just three days to cross the desert, with 09 taking a day longer. Each was clearly intent on crossing as quickly as possible; we recorded fastest speeds for both birds in Western Sahara – 29mph for AW and 50 mph for 09.
By the time he reached his wintering site on the Senegal coast 09 had covered 2972 miles from Rutland Water in 16 days – an average distance of 186 miles per day. AW flew further south to Guinea. He migrated 3277 miles in just 14 days - an average of 234 miles per days. Interestingly AW’s average speed was significantly slower than 09 – 15 mph compared to 29 mph – but by flying for longer each day, he completed his migration faster. The table below summarises the key facts of the two flights.
| AW | 09 | |
| Total distance flown | 3277 miles | 2972 miles |
| Duration | 14 days | 16 days |
| Average distance per day | 234 miles | 186 miles |
| Average speed | 15 mph | 27 mph |
| Fastest speed | 29 mph | 50 mph |
| Average altitude | 2431 feet | 1919 feet |
| Highest altitude | 9055 feet | 6112 feet |
Finally, here is Osprey fact of the day. 09 is thirteen years old and now we know where he has spent each winter since his first migration from Rutland Water in 1998. This means that in his lifetime he has migrated a staggering 75,000 miles. In other words he has flown round the world three times!
09 and AW settled in their winter routine
09 and AW may be wintering 600km apart – on the coastlines of northern Senegal and Guinea respectively - but their daily routines are very similar. The satellite data suggests that both birds are fishing in the sea twice a day; usually mid-morning and then again in the early evening. Of the two, AW generally heads further out to sea -sometimes more than three miles - whereas 09 hasn’t ventured more then a mile from the coast. Having watched Ospreys fishing in West Africa last winter, I imagine that it takes the birds very little time to catch their meal; probably just a matter of minutes. The remainder of their day is spent on their favourite perches. In AW’s case this is in mangroves 500m from the sea whilst 09 is usually perched among scattered trees just a couple of hundred metres from the breaking waves. All in all, being an adult Osprey at your established wintering site is a very easy life!
09's movements during the past ten days
AW's movements over the last ten days
If our experiences in West Africa are anything to go by, then the only other time that the birds will leave their perches, is to chase off other Ospreys. They will probably be fairly tolerant of the neighbouring adults birds – who they will recognise from previous winters – but less welcoming to newly arrived juveniles. We watched adults chasing juveniles numerous times last winter and this is one of the reasons that young birds wander about so much during their first winter in Africa. Here’s a video diary that we recorded in Gambia last winter. I suspect that the habitat at the winter homes of our two birds is very similar to that of Gunjur.
09 and AW settled at their winter homes
09′s latest data is in and it shows that, as we suspected, he has settled on the Senegal coast south of St Louis. So despite the fact that his territory in Rutland is just a few kilometres from AW’s, they are wintering 600km apart! Both birds have been making one or two short flights out to sea to fish each day before returning to their favourite perches just inland. Their routine is unlikely to change for the rest of the winter!
09 and AW's wintering sites in West Africa
I’ll provide a more comprehensive update of both birds’ recent movements next week, but in the meantime I’m off to run the Berlin marathon in order to raise money for our Gambia wildlife education project. Huge thanks to everyone who has sponsored me so far – through your generosity I’ve raised almost £3000. If you haven’t donated yet and would like to contribute to what we at Rutland Water feel is a very worthwhile cause, please check out my online fundarising page.
AW at his winter home
The latest data from AW’s radio proves that he has reached his winter home. Having roosted in the mangroves 500m from the shoreline on Friday evening, the GPS position at 8am showed him fishing just over 3km out to sea. An hour later he was back in the mangroves, presumably eating the fish.
Like most adult Ospreys at their established wintering site, AW will probably spend the winter in a very small area – using the same perches each day. It will be really interesting to follow his daily routine over the coming months.
AW fishing 3km out to sea
AW has made it to Guinea – and probably his winter home
Just after 3pm yesterday AW arrived on the Guinea coast 75 kilometres south of the border with Guinea-Bissau. On every other day of his fourteen day migration to West Africa he has flown until early evening, but yesterday was different. He spent the rest of the afternoon in a small area of mangroves, making one short flight to fish. It looks like he has reached his winter home.
Earlier in the morning AW hadn’t left his roost site until after 9am. He was fishing in the River Corubal at 7am and then must have spent a couple of hours eating it. He obviously knew that there was no need to rush.
By 10am he was heading south at 17kph and he crossed the border into Guinea just after 11am. At this point he switched to a south-easterly heading and this took him to the coast. He arrived just after 3pm after a day’s flight of just under 200km.
AW's flight, 9th September
If AW has reached his wintering site, then it has taken him just 14 days to get there; surely one of the fastest Osprey migrations recorded anywhere in the world? He covered 5274km (3277 miles) on his two week journey, an average of 376km a day. What an incredible migration.
AW's migration to Guinea - 27th August-9th September
AW reaches Guinea-Bissau, now how much further?
As we suspected, AW continued south through Senegal yesterday; skirting the eastern border of Gambia, and eventually roosting next to the River Corubal close to the Guinea-Bissau-Guinea border.
Having roosted in central Senegal AW set off again just before 9am and flew 150 kilometres south-west towards Tambacounda, the largest city in eastern Senegal. He skirted around the city at 2pm and turned slightly south-east, passing over the very eastern tip of Gambia. He continued on this course until 6pm when he turned south west as he crossed the border from Senegal into Guinea-Bissau. He continued for another 68km before stopping beside the River Corubal as dusk was falling at around 7:30pm after a day’s flight of just over 350km.
AW's flight, 8th September
The River Corubal is 150 metres wide and bordered by mangroves; typical over-wintering habitat for Ospreys in West Africa. On our trip to West Africa last winter myself and the team from Rutland Water saw numerous Ospreys perched in this sort of habitat. The resolution on the Google Earth images for this part of Guinea-Bissau isn’t good, but AW’s position at 9pm suggest that he roosted on an island in the river.
It is not inconceivable that AW has reached his winter home but the fact that he was flying right up until dark suggests thast he may well continue further south tomorrow. If he does then he could be in southern Guinea or perhaps even Sierra Leone by tomorrow evening!
AW's roost, 8th September
