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.
Has 09 reached his winter home?
09′s latest data has come through this morning and it shows that he spent all of yesterday (Sunday) on the Senegal coast, midway between Dakar and St Louis. It looks like he has probably reached his winter home.
The previous batch of data had shown that 09 made a distinct shift south-west on 15th September (Thursday), a flight path that appeared to be taking him down towards St Louis in northern Senegal. He had now almost crossed the vast wilds of the Sahara, but seemed to be feeling the effects of the long and arduous flight. He covered just 180km on Thursday - significantly less than the previous few days. He roosted that night amid high rolling dunes.
Next morning 09 resumed his migration after 9am, initially heading just west of south. By 11am he had covered just under 30km and was flying south at 44kph, 110m above the spectacular dunes. Two hours later he was another 45km further on and now made a distinct turn to the south-west. During the course of the afternoon he flew another 130km at altitudes of around 500 metres. He settled to roost just before dark in the Reserve Forestiere de Berbeira – an area of scattered trees in the south of Mauritania. His day’s flight was just over 200km.
09 was now within striking distance of the Senegal coast and his first fish for several days. He clearly knew it as well because he had already covered 25km south-west by 7am next morning (Saturday). Two hours later he had stopped again, but he didn’t rest for long. He crossed the mighty Senegal River just after 11am and flew south west over Djoudj National Park. I know Djoudj well having visited there with John, Paul and Frederic Bacuez three times last winter. Whilst in Djoudj we identified several wintering Ospreys from Germany and also YU – a female who fledged from the Lake District nest in 2007. I wonder if 09 encountered any of them as he flew over the park? Djoudj is a reminder that it is not just Ospreys who are migrating south this autumn. The park is home to more than 3 million migrant birds each winter. The photos below taken by John at Djoudj show Ospreys with two of those visitors – Garganeys and a Montagu’s Harrier.
German Osprey with Garganeys at Djoudj
Osprey and Montagu's Harrier at Djoudj
09 continued south west and passed to the east of St Louis at 1pm. He was making excellent progress and at around 4pm he reached the coast 73km south of St Louis. He had flown 225km.
Singificantly, 09 then spent all of yesterday at the same place, spending the majority of the day perched in a wooded area 150m from the beach and making one foray out to sea at 2:30pm. There seems every chance therefore, that this is 09′s established wintering site. We should know for sure when the next batch of data comes in. If this is the place where he has spent the last thirteen winters, then myself John and Paul were unknowingly very close to him when we visited the north of Senegal in January. We were less than 30 miles up the coast when we visited Langue de Barbarie. The coastline at Barbarie must be very similar to 09′s spot and so here are a couple of photos to give you an idea of what the coastline there is like. You might also like to read about our trip to Senegal, by checking out the blog we wrote out there.
It’s going to be really interesting to see if 09 is at the same place when the next batch of data comes in.
Osprey at Barbarie, Northern Senegal
Langue de Barbarie
09's flight - 15-17 September
A change of direction for 09
Since arriving in Africa 09 had followed a very similar route to AW, but yesterday that all changed.
On Wednesday evening 09 roosted on the edge of a spectacular dune system – just the kind of place that you imagine when you think of the Sahara. He arrived there some time before 7pm having flown 486km through the desert. He had maintained a SSW course all day that was remarkably similar to that of AW. In fact 09′s roost site that night was just 68km south-west of where his compatriate from Rutland had roosted on 5th September – a fairly inconsequential distance when compared to the vastness of the Sahara.
09's route through the Sahara, 13th Sept - with AW's route and roost site on 5th Sept for comparison
Next morning 09 did not set off again until around 10am and an hour later had covered just 28km. Interestingly, he was now heading in a much more westerly course than previous days. Whether this was a conscious descision or the effect of a strong easterly wind remains to be seen, but by 5pm – the final location in this batch of data – he had covered 156km in a distinctly south-westerly heading. This suggests, that unlike AW, 09 is heading for the Senegal coast. With this in mind I e-mailed Frederic Bacuez – the French ornithologist myself John and Paul stayed with at his home near St Louis last winter – and asked him to keep an eye out for 09. You just never know!
09's flight through Mauritania showing his change of direction on 15th September (AW's route (right) also shown for comparison)
As ever, it will be really interesting to see where he is when the next batch of data comes in.
09 reaches central Mauritania
09′s latest batch of data is just starting to come through and a non-GPS position showed that he was in central Mauritania at 6:50am this morning. This means that by this evening he should have completed his crossing of the Sahara and reached Senegal.
The previous data had shown that 09 was 48km south west of Agadir and heading out into the desert at 9am on Monday morning (12th September). By 1pm he was another 125km further on, heading south-west at 68kph. This course took him over the speactaular ridge the runs across the northern edge of the Sahara, just before 3pm. The photos below show the ridge photographed from the plane as myself and the team from Rutland Water flew to West Africa last winter.
At 5pm 09 was circling more than 3000 feet above the desert, perhaps looking for somewhere to spend the night. He had covered 290km.
The next GPS data shows that at 11am next morning (Tuesday 13th) he was another 147km further south west, circling over the desert, presumably using thermals to gain height. By 3pm he had covered another 157km, following a remarkably similar route to AW. In fact 09 actually crossed the path taken by AW between 1pm and 3pm that afternoon.
09 and AW flying over the Sahara
We are still waiting for the remainder of the GPS data to come through and I’ll update the page once it does. In the meantime a single non GPS (but accurate) position showed that by this morning he had covered another 660km south-west across the desert, still following a similar course to AW. He had now covered at least 1250km since Monday morning.
09's latest position in the Sahara
