Crossing the Sahara

Over the past few weeks we’ve been wondering when our satellite-tagged osprey, Jules, would set-off from his wintering site in the Casamance region of southern Senegal. Ospreys with established nests usually leave in mid-March, but younger birds often depart later. Jules was unringed when we tagged him at Rothiemurchus Fishery last September, and he then set-off on migration the very next morning; meaning we do not know how old he is, or if he has an established nest site. It also made predicting his spring departure more tricky.

We tagged JV3 in September last year at Rothiemurchus Fishery

Jules finally left his wintering site on Saturday 14th April: a relatively late departure that indicates he is probably a young bird without a nest to reclaim. Nevertheless he has made excellent progress and last night he roosted just south of the Atlas Mountains in Morocco having flown 2336 km during his first six days of migration, and successfully crossed the Sahara. Here’s a day-by-day summary of his journey so far.

Saturday 14 April 

Jules set-off from his wintering site in the Casamance region of southern Senegal at approximately 11:00 GMT. He flew 191 km ENE at a maximum altitude of 1316 m before stopping to roost a few kilometres south of the River Gambia.

Sunday 15th April 

Jules left his overnight roost at around 09:30 and headed across the River Gambia soon afterwards. By 12:47 he had flown 81 km due north, and at this point he changed his heading to north-east. He maintained the same bearing for the rest of the afternoon before settling to roost close to the border of Senegal and Mauritania after a day’s flight of 340 km.

Monday 16th April 

After a couple of short local movements Jules resumed his migration at 09:30 and crossed into Mauritania soon afterwards, with the vast and desolate Sahara ahead. The wind must have been in his favour because he maintained a perfect north-easterly heading during the course of the day, flying a total of 349 km across the desert at a maximum altitude of 1464 m.

Jules’ first three days of spring migration

Tuesday 17th April 

Having roosted on the desert floor, Jules began migrating again at approximately 09:00 GMT. Unlike the previous day he set-off on a northerly heading, and then maintained it for the rest of the day, crossing the Akchâr Desert region of central Mauritania. He made particularly fast progress during the middle part of the day when thermals would have been strongest, covering 208 km in four hours after midday. When he finally settled to roost at around 19:15 he had flown an impressive 503 km during the day and was now close to the border with Western Sahara.

Wednesday 18th April 

Jules left his roost site just before 09:00 GMT and headed north. By 14:00 he had flown 237 km and at this point he turned more to the north-east, appearing to follow ridges in the desert below. He maintained this heading for the rest of the afternoon, flying at altitudes of up to 2000 m. He eventually settled to roost in northern Western Sahara shortly after 19:00 after a day’s flight of 437 km.

Jules appeared to be following ridges than run north-east across the northern part of the Sahara during the afternoon of the 18th April

Thursday 19th April 

Jules was now nearing the end of his crossing of the Sahara and he left his roost site in the desert at 09:15. As the previous afternoon he maintained an almost perfect north-easterly bearing as he crossed the northern reaches of the Sahara into southern Morocco, flying at a maximum altitude of 2500 m. He passed well to the east of Tiznit and continued across the Anti-Atlas Mountains until after dark. When he finally settled to roost at 20:30 he had flown 516 km during the course of the day and was approximately 100 km east of Agadir.

Jules has made fast progress across the Sahara over the past four days

All being well Jules will have crossed the Atlas Mountains today, and will reach Spain over the weekend. We’ll have another update on his progress early next week. In the meantime you can check out Jules’ flight so far on our interactive map.

Osprey stamp – a special appeal

Later this month the Royal Mail are releasing a series of special stamps to celebrate successful reintroductions in the UK. We are delighted that they have chosen the osprey as one of the six featured species given our work in both the UK and around Europe over the past two decades. The Foundation, and Roy in particular, has been a key driving force behind the two English translocation projects at Rutland Water and Poole Harbour as well as others in Spain, Italy, Portugal and Switzerland.

The osprey stamp is being released by the Royal Mail on 17th April

To mark the occasion we are launching an appeal to raise money for our ongoing osprey conservation work. The first 200 people who make a donation of £10 or more to this appeal will be sent a limited edition postcard signed by Roy, with the osprey stamp affixed. The postcard features images of some of the key ospreys involved in the English reintroductions: 03(97), a male that we translocated to Rutland Water in 1997 and who went on to raise 32 chicks; Green J, an adult female who bred at a nest in Strathspey for many years and produced chicks for translocation to Rutland Water as well as Andalucia and the Basque Country in Spain; and LS1, one of the eight juvenile ospreys that we translocated to Poole Harbour last year. The postcards will be sent in envelopes to ensure that they are not damaged in the post.

The limited edition postcards will be signed by Roy and have the osprey stamp affixed.

All money raised by the appeal will go directly towards our ongoing osprey conservation work, including:

  • Artificial nest building
  • Monitoring and protection of breeding ospreys
  • Coordinating the UK colour-ringing scheme and presenting the results online via our interactive map
  • Translocation projects
  • Satellite tracking

To support the appeal simply make a donation of £10 or more by clicking the donate button below. We’ll then get in touch by email to confirm where you would like the postcard sent.

Thank you very much for your support.

Sad news about LS6

In January we were delighted to learn that two of the eight juvenile ospreys that we translocated to Poole Harbour last summer had been seen at the Sine-Saloum Delta. This vast area of mangrove swamps and shallow tidal water is a perfect place for wintering ospreys, and so it was extremely encouraging that the two birds were seen there.

We have now received news of a third Poole translocated bird in West Africa, but sadly this one – LS6 – was found dead near Kartong in The Gambia. The bird’s body was initially found by local people and the corpse was then relocated by Dembo Jatta, who took the photos below. There were no obvious signs of death, and so we can only assume that it died of natural causes, which is common among young ospreys. The demands of the first migration, coupled with difficulties associated with finding a wintering site, mean that mortality among juvenile ospreys is very high, with only around 20-30 % of birds returning to the UK as adults. Juvenile ospreys are often chased away from the best areas by aggressive adult birds, and can end up in marginal habitat where food is harder to come by, and chances of mortality much greater. All manner of dangers lie in wait for inexperienced young ospreys, particularly those already in poor condition.

The body of LS6 was found by local people near Kartong in the south of The Gambia

 

The area where LS6 was found, just north of the River Allahein – which forms the southern border of The Gambia and Senegal – is an excellent place for wintering ospreys, but of course what we don’t know is how long he had been there before he died. Most juvenile ospreys do not settle down at a particular site until the summer of their second year, and so LS6 would still have been in the exploration phase and may have only just arrived in this part of The Gambia when he died. Sadly the bird’s body provided no conclusive evidence as to what had happened. Very many thanks to Dembo Jatta, as well as Olly Fox and Colin Cross of Kartong Bird Observatory for the information and photos.

LS6 was found just to the north of the River Allahein in the south of The Gambia

LS6’s body was found 65 km south of the location of the January sightings of LS3 and LS7

Although it is very sad that LS6 has been found dead, the fact that we now know that at least three of the eight birds we released completed migrations to West Africa indicates that they left Dorset in excellent condition; and this is testament to the superb work of the team at Poole. It is also likely that the proximity of Poole Harbour to the English Channel gives the translocated birds an advantage. The crossing from Poole to the Cherbourg peninsular in France is just 60 miles and once there the juveniles can follow the Atlantic coast of France as they migrate south, rather than attempting a dangerous crossing of the Bay of Biscay. So despite the bad news about LS6, there is plenty of reason to remain hopeful about the other birds.

POSTSCRIPT

After publishing this blog we were sent a photo of LS6 taken by Paul Hill near Kartong Bird Observatory (just 2.5 km from where the bird was subsequently found dead) on 16th January. This was just under two months before the bird’s body was found. The photo shows that a big chunk of the tail is missing – suggesting that LS6 may have been attacked by a dog, or perhaps even a crocodile. Ospreys spend a great deal of time perched on the ground, which greatly increases the chances of naive, inexperienced juveniles being predated. Although it seems LS6 had a close escape initially, it is possible that the loss of so many tail feathers impaired its ability to fish successfully. It’s a mystery that will remain unsolved, but this seems the most plausible explanation at present.

LS6 had much of his tail missing when he was photographed by Paul Hill on 16th January.

Elswehere we were delighted to learn last week that the mother of one of the Poole Harbour birds is on her way back to Scotland. 15 year-old Morven raised three chicks last year, one of which was translocated to Poole (LS7 – who was seen in Senegal in January), and another to the Basque Country. On Wednesday last week she was photographed at her regular spring stop-over site at Ría de Villaviciosa in Asturias. Morven was originally ringed as a chick on Forestry Commission land in Moray in 2003 and was then satellite tagged by Roy five years later. This showed that she migrated to the coast of Mauritania and stopped off at the Villaviciosa estuary each spring. Her transmitter was eventually removed but she continues to breed in Moray.

Very many thanks to Miguel Puente for the photo and sending details of his sighting.We have uploaded details of the sighting of Morven as well as several other new birds onto our interactive migration map.

Morven was photographed at the Villaviciosa estuary by Miguel Puente on 21st March.

Life’s a beach

In our last update on the latest movements of our satellite tagged osprey, Jules – who is wintering in the Casamance region of southern Senegal – we reported that he was dividing his time between favoured daytime perching and fishing spots on the coast and a regular roost site in mangroves 16 km inland. This is quite unusual given that most adult ospreys usually occupy a very small winter territory.

Jules has continued to favour the same stretch of coastline since the turn of the year, but over the past month he has also started roosting on the coast; usually among scattered trees about 800 metres from his favoured stretch of sand. Over the past month he has roosted on the coast more often than inland. Quite what has promoted this change of behaviour is unclear, but by doing so he is avoiding the necessity of a 32 km return flight each night.

Jules has been favouring a 1 km stretch of beach during the past two months.

Other than this change in roosting location, Jules’ behaviour has been much the same as the rest of the winter. He has favoured the same 1 km stretch of beach and continued to fish just offshore once or twice each day. Most of his fishing is done within 200 m of the shore, but on at least two occasions since 1st January he has flown further out to sea (1.5 km or more). When he roosts on the coast he is favouring an area of just over 1 km which is much more typical of the usual winter range of an adult osprey.

Jules’ latest movements – including a flight to the east on 16th February

Interestingly Jules roosted inland on the nights of 15th and 16th February and during the afternoon of 16th February flew 25 km to the east – perhaps flying around with other ospreys – and spent a few hours perched in creeks near Tionck Essil. Next day however he was back at his favoured spots on the coast and he roosted there that night.

Jules is likely to remain in Senegal until mid-late March before beginning his migration back to Strathspey.   You can check out all of his latest movements on our interactive map. Our other satellite tagged osprey, Blue DF is wintering 30 km ENE near the village of Baila, but unfortunately we have stopped receiving data from his transmitter due to a technical fault. There is more information here.

LS3 seen at the Sine-Saloum Delta

Last month we were thrilled that LS7, one of the eight juvenile ospreys that we translocated to Poole Harbour last summer, had been seen at Ile des Oiseaux in the Sine-Saloum Delta in Senegal. You can read more about the sighting here. The survival rate of juvenile ospreys in their first year is generally very low (only around 30% make it back to the UK as a two year-old) and so it was encouraging that LS7 had been seen at such a superb place for wintering ospreys.

Amazingly we now know that LS7 wasn’t the only Poole juvenile to be seen at the Sine-Saloum Delta in January. We have now been contacted by Jean-Louis Carlo to say that he photographed LS3 on New Year’s Day at Nema Bâ in the south of the delta. LS3 set-off from Poole Harbour two weeks after LS7, on 9th September but amazingly Jean-Louis’ sighting was just 21 km from the spot where LS7 was seen three weeks later! This really is fantastic news and proves that the two juveniles must have set-off from Poole in excellent condition; undoubtedly aided by the daily supply of fresh fish provided by the team at Poole before the juveniles departed. This is an essential requirement if a young osprey is to survive the perilous first migration to West Africa and then find somewhere safe to winter.  As we explained in the recent blog about LS7, LS3 may not have lingered at the Sine-Salum Delta, but Jean-Louis’ sighting is an extremely encouraging sign. This incredible place will now be on the young osprey’s radar, and may well become his future wintering site.

LS3 at the Sine-Salum Delta on 1st January 2018 – photo by Jean-Louis Carlo

LS3’s ring is clearly visible in the photo

Both LS3 and LS7 are likely to remain in West Africa for the whole of 2018, but the fact that they have both been seen alive means that there is every chance that we may see them back in Dorset in spring 2019. Here’s hoping!

Very many thanks to Jean-Louis for this fantastic news.

You can check out the location of the sightings of LS3, LS7 and other colour-ringed ospreys from the UK on our interactive map.

LS3 and LS7 were seen just 21 km apart in the space of three weeks

LS7 seen in Senegal

It is always exciting to receive reports of colour ringed ospreys during winter, but earlier this week we got an extra special one. On Monday Adama Lene, a ranger at the Saloum Delta National Park in Senegal, was out surveying birds at the aptly named Ile des Oiseaux; a long sandy island that lies at the mouth of the delta, with the Atlantic Ocean to the west and 180,000 hectares of shallow water, inter-tidal mangroves and savanna woodland to the east. It is named after the thousands of Caspian terns which breed there each year, but in winter ‘Ile des Balbuzard’ would probably be more appropriate. It is not uncommon to see 20 or 30 ospreys perched within close proximity on the sand. Fishing is easy in the rich, shallow waters of the delta and the island provides the perfect place for the wintering ospreys to eat their catch and then rest during the day. Both myself and Roy have been privileged to visit the island on a number of occasions and each time we have seen colour ringed ospreys, including several birds from Scotland as well as others from Germany. As they eat their fish on the sand, with blue-cheeked bee-eaters zipping around overhead, the ospreys are surrounded by turnstones and slender-billed gulls which often steal pieces of fish. In 2011 Roy visited Ile des Oiseaux with BBC Autumnwatch and observed this interesting behaviour. Click the link below to watch.

Having been with us when we’ve been checking out the ospreys for colour rings Adama is well versed in what to look for. Now each time he visits the island, he checks the assembled ospreys for ringed birds.  On Monday he was pleased to see an osprey with a blue ring on its right leg, bearing the inscription LS7. He didn’t know it at the time but, amazingly, he had found the proverbial needle in a haystack: one of the juvenile ospreys that we translocated to Poole Harbour last summer; and the first sighting of any of the birds since they left Dorset.

Many juvenile ospreys are chased away from the very best sites by adult birds when they first arrive in West Africa, and are pushed into peripheral habitat where their chances of survival are greatly reduced. It is extremely encouraging therefore that LS7 is at such an excellent site. Although there is no guarantee that he will stay – young ospreys usually explore over thousands of square kilometres during their first winter in Africa – Ile des Oiseaux will now be on his radar; meaning that even if he continuous his wanderings, he may well return at a later date.  Our satellite tracking studies have shown that most juveniles eventually settle at a specific site after about six months in West Africa, which coincides with adult birds heading north again. Most juveniles, on the other hand, remain in Africa for the whole of their second calendar year which helps them to get established at their chosen site.

Ile des Oiseaux lies in the mouth of the vast Sine-Saloum Delta in Senegal, just north of The Gambia

LS7 was the first of the birds to fly after release on 31st July

LS7 was the first of the translocated juveniles to fly after release on 31st July and also the first to set-off on migration, on 25th August. It is very apt therefore that he is now the first to have been seen since leaving Dorset. The first 12 months of a young osprey’s life are incredibly demanding and we do not know how many of the seven other birds from the 2017 cohort survived their first migration. Colour ringing and satellite tracking studies show that they could be wintering anywhere from Spain to the Ivory Coast, so the fact that we now know where one of them is, is remarkable. The return rate of translocated ospreys to Rutland Water was only around 20%; so in all likelihood we may see one or two of the 2017 birds returning next year. Adama’s sighting suggests there is every chance that one of them will be LS7; especially if he settles at the island of the birds.

Wintering ospreys often perch together on the Ile des Oiseaux (photo by John Wright)

Rothiemurchus – relocated!

One of the most interesting ospreys that we have satellite tagged in recent years is Rothiemurchus. After being tagged as a chick in a nest on the Rothiemurchus Estate near Aviemore in 2009 the young male headed south in early September and made a long overnight crossing of the Bay of Biscay. He drifted west in strong easterly winds and missed the north coast of Spain, before finally making landfall in Portugal after a flight of 1302 km in 33 hours. He then remained in Portugal for more than a month before continuing south and migrating to Djoudj National Park in northern Senegal. In January 2010 he made several exploratory flights into Guinea Bissau before settling in the backwaters of the River Gambia in Senegal. He obviously found excellent fishing on these marshes and spent the whole year there, with a little exploration into The Gambia. He remained in the same location until May 9th 2011, when he set off on his first migration back to Scotland. We followed this and seven subsequent migrations between Scotland and his wintering site in Senegal. During these journeys it was clear that he had learnt from his first arduous crossing of the Bay of Biscay and, in order to return to favoured stop-over locations in Galicia in northern Spain that he had used on his first northward migration, he made the most amazing dog-leg migration across the north coast of Spain, as shown in the animation below. It was also fascinating to see how widely he ranged in Scotland when he first returned in 2011 and then in subsequent summers.

We tracked Rothiemurchus for five years between 2009 and 2014. Orange lines = autumn migrations, white = spring.

Once back at his wintering site each year, Rothiemurchus settled into a very predictable pattern of behaviour, living in a very small area of less than 1 km². This enabled myself and colleagues from the Rutland Osprey Project to see him in January 2012 (watch video below) and Chris Wood to do the same in February 2013.

In November 2014 Rothiemurchus was back in Senegal but no signals were received from his transmitter after the night of 7/8 November. Having inspected the data closely, Roy felt sure that the transmitter had either failed or fallen off, but without seeing the bird could not be sure. The problem was that although Rothiemurchus was now five years old and had settled in Perthshire, he had yet to establish a nest site of his own; and so there was no specific place to look in spring 2015 when he should have returned to Scotland. A further two summers have since passed without a confirmed sighting, but on Wednesday this week Chris Wood and Joanna Dailey, along with Junkung Jadama and Fansu Bojang, decided to visit Rothiemurchus’s regular wintering site on the off chance that he might still be alive.

And guess what? They saw him! Here are two photos taken by Chris and Joanna in which you can just make out the transmitter on the bird’s back.

Rothiemurchus was perched on a dead tree in exactly the spot where he spent previous winters (photo by Chris Wood)

The transmitter is just visible in this photo – with a snapped aerial (photo by Joanna Dailey)

We are thrilled to know that Rothiemurchus is still alive, and that Chris and team have been able to prove that the lack of data was due to transmitter failure as Roy always suspected was the case. Sincere thanks to Chris, Joanna, Junkung and Fansu for making the effort to go and look – a superb piece of fieldwork. Here is an extract from an email from Joanna this evening:

“It was a real thrill to see what we hoped would be Rothiemurchus, and then to see the transmitter on my not very good photos. They will be special now.

He left his perch to escort an unringed Osprey away, although it wasn’t the determined removal you see in breeding Ospreys. He went high with the other one and they drifted away. We were still in the area for over 30 mins, but we didn’t see him return.

A villager was harvesting oysters fairly nearby, Rothiemurchus would have been aware of him. You can see the oyster shell piles on the Google Earth images I made, so villagers must be around the area quite a bit, in addition to fishermen in pirogues.”

As Joanna’s photo shows, the reason for the lack of data is now clear – the aerial on the transmitter has snapped off. Now we know this we will make a concerted effort to find Rothiemurchus once he has returned to Scotland in the spring, not only to discover where he is breeding (which he almost certainly will be by now) but also to attempt to re-catch him and remove the defunct transmitter. For now though it is just great to know that this osprey, whose migrations we have followed with such interest, is still alive.

The location of yesterday’s sighting was in exactly the same place as data from 2014.

Daily routines

Over the past two decades satellite tracking has provided a unique insight into the wintering behaviour of ospreys. Whereas juveniles usually wander over a large area after arriving in West Africa, adults head straight to a known wintering site. Many of the adult birds we have tracked have been remarkably sedentary in winter; often occupying a home range of 1-2 km². There are always exceptions to this rule, however, and it has been fascinating to follow the daily movements of Jules since he arrived at his winter home in the Casamance region of southern Senegal. Jules is living in a larger area than most adult ospreys, but mainly because his regular roost site is 16 km from his favoured daytime perching and fishing sites.

Jules has spent each night roosting in an area of dense mangroves, and has four favoured perches within an area of just 0.04 km².

Jules roosts in an area of dense mangroves each night.

In this part of the Casamance delta he is surrounded by potential foraging grounds, including a section of river that is almost 1 km wide, just 2 km to the south. However the satellite data indicates he does little or no fishing in this area, and instead flies 16 km WSW to spend each day on the coast. There he favours a 1.3 km stretch of sandy beach and hunts just offshore. The satellite data indicates he probably catches most of his fish around 200 m out to sea, but on occasion he flies further out, such as 1.1 km on 3rd December and 2.65 km on 19th November. Most of these fishing trips tend to be late morning or early afternoon, and he then eats his catch on the beach.

Jules spends most days perched on a sandy beach, and fishing just offshore.

The map below gives an indication of just how predictable his daily routine is. The red circle, centered on his roost sites, indicates an area with 50 % of GPS fixes while the orange area shows the location of 95 % of fixes. In other words, when he is not at his roost site he is nearly always at the coast. Interestingly he has flown east from his roost site on just two occasions in the past month.

Over the past month Jules has roosted in the mangroves each night and then flown 16 km WSW to spend the day on the coast. The red circle indicates an area with 50% of GPS fixes and orange shading 95% of GPS fixes (calculated using kernel method).

Jules’ winter home in Senegal is 30 km south of The Gambia and 20 km north of the Casamance River.

Don’t forget that Jules’ latest winter movements as well as his migration from Scotland are shown on our interactive map.

The Deaf Birder’s Bird and the elusive Lynx

At dawn today it was snowing in the garden, and by the time I was ready to go for my morning walk nearly an inch of snow lay on the ground. I love walking in fresh snow as it gives me a chance to find out what unseen creatures are around. When I reached the edge of a nearby plantation, I could see that a young roe deer had crossed my path only minutes before, leaving a trail of black slots. Further up the track were the distinctive prints of a brown hare, louping up the road. On my return there was nothing new except dozens of tracks, etched in the snow, of a bird more usually obvious at dusk than at dawn. Last week, my wife and I walked this our favourite route just before sunset as dozens and dozens of pheasants were settling in the trees for their night roosts. The winter sun now sets in the southwest and the birds in the leafless birches were outlined against a golden sunset. As we walked, some burst from the branches, others crowed loudly.

Nowadays, the ‘Deaf Birder’s Bird’, as Moira calls them – knowing that I now find it hard to hear the high-pitched calls of small passerines – is the commonest bird in our immediate vicinity, as thousands are reared for hunting. I could try closing my eyes and imagining that the sounds were in fact coming from great trees on beautiful mountain slopes in their native lands of Asia. This morning, though, I reflected on which prints, instead of theirs, I would really like to have seen crossing my morning path. That memory jog always takes me back to the mountain forests of Transylvania, where several times I have followed the tracks of brown bear and wolf, as well as the animal which, in that moment, I realised I would most like to see making tracks in the Scottish snows again: the Lynx. Many of us have talked for years about its reintroduction, ecologically simple but politically, it seems, impossible. We have to be fairer to nature, though: if we can host millions of pheasants, surely we can restore the long-lost lynx? So let’s get on with it and again allow us all the thrill of seeing those exciting paw prints padding along snowy forest tracks in Scotland.

Thanks to Stephane Regazzoni – trail camera shot French Jura

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)

Date Distance (km) Location
14 Sept 420 Scotland-England
15 Sept 584 England-France
16 Sept 122 France
17 Sept-2 October Stop-over, Gulf of Morbihan, France
3 Oct 515 France-Spain (Bay of Biscay)
4 Oct 181 Spain
5 Oct 462 Spain
6 Oct 168 Spain
7 Oct 75 Spain
8 Oct 524 Spain-Morocco (Atlantic)
9 Oct 127 Morocco
10-16 Oct Stop-over, Morocco
17 Oct 128 Morocco
18 Oct 323 Morocco
19 Oct 544 Sahara
20 Oct 445 Sahara
21 Oct 485 Sahara
22 Oct 461 Senegal
23 Oct 153 Senegal-Gambia-Senegal