Poole Harbour Ospreys 2021

2021 is proving to be an encouraging year for the Poole Harbour Osprey Project, which we run in partnership with Birds of Poole Harbour and Wildlife Windows.

The long term aim of the project is to restore a population of Ospreys on the South Coast of England, where they have been absent for 200 years. This involves the translocation of young from nests in Northern Scotland. You can learn more about the project in our podcasts here.

Young Ospreys usually return to the UK for the first time in their third calendar year, and so this spring we were hopeful we would see some of the birds released in 2019 back in Dorset for the first time. Satellite tracking studies have shown that young Ospreys wander widely when they first return, but they usually visit their natal site (which in the case of the translocated birds is the release site) at some point during their first summer back in the UK. A key part of this behaviour is to prospect potential breeding sites, and, as a result, young birds often intrude at active nests. The movements of satellite-tagged male Rothiemurchus when he first returned to Scotland in 2011, is a good example of just how far young birds wander before they establish their own nest site.

In the early years of colonisation, it is usually males who establish territories, before attempting to attract a mate, but the difference for any returning male to Poole Harbour this year, was the presence of an unpaired female. CJ7 fledged from a nest in Rutland in 2015 and has returned to the Poole Harbour area each summer since 2017. It seems that the presence of translocated juveniles in the area has been a key factor in her settling in Dorset. She paired with a translocated bird, LS7, in 2019 but sadly the young male failed to return from migration last spring. Unperturbed, CJ7 has remained faithful to the same artificial nest for the past two summers and has laid unfertilised eggs on each occasion, demonstrating her eagerness to breed.

As those of you who have watched the Birds of Poole Harbour live stream this summer will know, there was great excitement on 18th May when CJ7 was joined at the nest by 022, a male that we had translocated from a nest in Strathspey in 2019. The two birds paired up immediately, and were seen mating regularly. It is highly unusual for two year-old Ospreys to breed, but we were hopeful that CJ7 may lay eggs in late May. That did not happen, but the two birds have remained together since, and, assuming they both return from migration, we are hopeful that they will attempt to breed next spring. What is not so certain is with nest they will choose – in recent weeks they have been seen at various artificial nests around Poole Harbour, and have been interacting with this year’s newly-released juveniles, even perching on nests with them.

022 (left) and CJ7 on the nest
The two birds began mating almost immediately

Whilst the key long-term aim of the project is to restore breeding Ospreys to the South Coast of England, early evidence is showing that this new population will also help to link different populations of Ospreys. The presence of translocated birds in and around Poole Harbour has led to CJ7 taking up residence in Dorset, while a female that we translocated to Poole has bred successfully in Wales for the first time this summer. 014, a female released in 2018 has bred for the first time this year at a nest at Pont Croesor in the Glaslyn Valley near Porthmadog in North Wales. She raised a single male chick (ring number 494), with a four-year-old male, Z2 or Aeron, from the Cors Dyfi nest in mid-Wales. Meanwhile a second female, 019, released at Poole Harbour in 2019, was also seen in Wales earlier this summer. She was captured on camera when she visited the nests in the Glaslyn Valley on 5th June. This was the first sighting of her back in the UK, although she was seen on a number of occasions at Gunjur Quarry in The Gambia during her first winter and again in March this year. She was subsequently seen at Cors Dyfi further south in Wales on 30th June and possibly again on 5th July. This demonstrates how widely young birds wander when they first return; helping them to develop important knowledge of where other Ospreys are breeding. It will be very interesting to see if and where the young female appears next spring. Research has shown that male Ospreys typically breed close to their natal site, but females often disperse further, and so it is possible that 019 may follow 014’s lead and also return to Wales in future years to breed. Or should another translocated male return and set-up territory at Poole Harbour, we may yet see her back in Dorset.

019 at Gunjur Quarry in The Gambia in January 2020 (photo by Chris Wood)

A key element of the project at this early stage is the continued release of young birds, and during July we translocated a further ten juvenile Ospreys from nests in Moray and Highland. The young Ospreys are collected under a special licence issued by NatureScot from broods of two or three and then held temporarily at Roy Dennis’s home near Forres, before being transported by road to Dorset. You can hear more about our work collecting Ospreys by listening to one of our podcasts from 2019 here.

Once the birds had arrived at Poole Harbour on 15th July they were immediately moved into holding pens and monitored by the Birds of Poole Harbour team. CCTV cameras enable the birds to monitored closely during this period and released when appropriate. The first five birds were released on 2nd August with the remaining younger birds making their first flights ten days later.

Two of the translocated juveniles feeding after release. Magpies often take advantage of a free meal at the release site too.

The post-release period is critical in the imprinting process because it is when the young Osprey learn that Dorset is home. They generally remain close to the release pens for the first ten days, before venturing further a field and exploring the wider landscape. Fresh fish is provided by the team on a daily basis in order to replicate what happens at natural nests, and so even when the young birds make longer exploratory flights, they usually return in the evening to feed. Most young Ospreys do not catch their own fish until they depart on their first migration, and so the fish provided by the project team is essential in helping the birds to get into the best possible condition for the long flight south.

In the last few days the juveniles have been seen in the presence of CJ7 and 022. At Rutland Water there were instances of non-breeding adults feeding translocated juveniles, and we wonder if that may be repeated in Dorset this summer. Both 022 and CJ7 tolerate food-begging juveniles perching on artificial nests with them, and it will be interesting to see if they respond to the incessant food-begging, by providing fish. Regardless, the presence of the young birds will further strengthen the very strong bond that both CJ7 and 022 already have to the area.

Translocated juvenile 375 food begging to 022 (left) and CJ7 on an artificial nest at Poole Harbour

This year’s juveniles are likely to remain at Poole Harbour until early September before setting off on their first migration. An excellent way of seeing them before they depart is to join one of the Birds of Poole Harbour Osprey cruises. You can find out more here.

New Year in Senegal

The latest satellite data shows that juvenile osprey, Deshar, is still settled on the Senegal coast. Over the past month she has favoured the same 10 km section of coastline, spending the vast majority of time on two peninsulas, some 5 km apart. This is an area favoured by many wintering ospreys, but the fact that Deshar is still there shows that she is holding her own amongst adult birds; some of whom will have been returning to the same area for many winters.

Deshar has spent the past month living on a 10 km section of the Casamance coastline in Senegal.

One interesting feature of this latest satellite data is how far she is travelling out to sea. During the winter ospreys will generally catch one or two fish every day, and the satellite data indicates that Deshar normally catches her fish close to the shore. However she has flown between 5 and 10 km out to sea on at least eight occasions during the last month. Ospreys tend to prefer to fish in shallow water, so perhaps she is visiting shallow off-shore reefs? It will be interesting to see if this behaviour continues over the coming weeks.

Don’t forget you can follow all of Deshar’s movements on our interactive map.

Deshar still in Senegal

Over recent weeks, our satellite-tagged juvenile female osprey, Deshar, has remained on the coast of Senegal. In fact between 19th October and 23rd November she was extremely sedentary, spending the vast majority of her time on the same peninsular in the norther part of the Casamance River Delta, that she had favoured since early October. Google Earth imagery indicates that the peninsular is fairly well vegetated, meaning that Deshar was able to roost there each night and then spend much of the day perched on the sandy shore with one or two flights out to sea each day to catch fish.

Deshar was extremely sedentary during October and much of November

On 23rd November she flew just under 20 kilometres south to the mouth of the Casamance River and spent several days exploring the northern and southern shore. These exploratory flights are an important part of a young osprey’s first winter in West Africa – helping them to learn the landscape and decide where is best to settle for the winter.

In late November Deshar spent just over a week at the mouth of the Casamance River, moving between the north and south shore

On 2nd December Deshar flew back north and returned to her favourite spot on the peninsular and the latest data shows she’s still there. It is encouraging she’s gone back there – and indicates that she is not being chased away by adult ospreys, which is one of the key challenges juvenile ospreys face after arriving in West Africa for the first time.

Deshar’s GPS fixes over the past six weeks

You can also check out Deshar’s movements on our interactive map.

Deshar settled in Casamance

One of the challenges for young Ospreys when they first arrive in Africa, is finding somewhere safe to spend the winter, and, crucially, where they are accepted by the wintering adult birds. The most recent satellite data show that Deshar appears to have done just that. She has spent the vast majority of the past fortnight living along a sandy spit in the Northern part of the Casamance River Delta. In fact she is just three miles south of an area that we know was frequented by another of the Ospreys we satellite-tagged in Scotland – Jules.  We know that  is a superb place for wintering Ospreys.

The satellite data indicates that the young female is spending most of each day perched on the sand, fishing in the sea at least once daily and then roosting in vegetation on the spit.  Last winter Joanna Dailey, from the Kielder Osprey Project, visited this part of Senegal and sent us some photos which show the spit just to the north. Joanna saw a large number of Ospreys in the area, demonstrating that it is an excellent location for Deshar to have settled. Let’s hope she stays there.

Deshar has been living on a sandy spit in the Casamance River Delta.

A photo of two Ospreys on a spit immediately to the north of Deshar’s favoured area. This was taken by Joanna Dailey during a visit to Senegal last winter.

Deshar has been spending most of her day perched on the sand – just the link the bird in this photo, taken by Joanna Dailey last winer, which is perched on a stump.

Don’t forget you can also check out Deshar’s latest movements on our interactive map.

Deshar returns to the Casamance

Last week the satellite data showed that on 24th September, Deshar flew north from the Casamance region of Senegal across the River Allahein, into The Gambia. We now know that next day the young female continued north and at 13:00 she landed on Bijoli Island – a small sandy island just off the coast at Tanji. This is one of the best areas for Ospreys in The Gambia. In fact Gambian bird guide, Junkung Jadama, recorded a piece from Tanji beach for this week’s podcast. After landing on the island for twenty minutes Deshar appeared to attempt to fish in the shallow water nearby. She would definitely have encountered adult Ospreys there, and perhaps that’s why she headed south soon afterwards – almost certainly without a fish. During the course of the afternoon Deshar continued south and paused briefly at the wetlands close to Kartong Bird Observatory before continuing onwards back into the Casamance. At 17:30 she returned to the same part of the Casamance coastline that she has been frequenting prior to her journey north after a day’s flight of 108 km (67 miles).

Deshar flew over Tanji beach in The Gambia on 25th September

Since then Deshar has been wandering around a 10 mile section of coastline in coastal Casamance – fishing in the sea, perching on the sandy beaches and roosting in coastal mangroves. This is a superb place for a juvenile Osprey to be exploring. Life isn’t easy for young Ospreys when they first arrive in Africa, but Deshar is doing very well so far. Let’s hope that continues.

Deshar flew over 100 km through The Gambia and back into Senegal on 25th September

Over the last week Deshar has explored a ten mile section of the Casamance coastline

You can check out Deshar’s movements on our interactive map.

Deshar is also featured in this week’s podcast. Click the link below to listen.

Deshar makes it to West Africa

In our last update Deshar had almost completed a crossing of the Sahara from Algeria to Senegal. We now know that the young female roosted just north of the Mauritania-Senegal border on the evening of 18th September after a superb eight day flight across the desert. However, not content to rest after her arduous flight, Deshar flew another 500 km south-west over the course of the next two days and by the evening of 20th September she was close to the very eastern part of The Gambia. Next day she continued south-south-west across the River Gambia and then into the Casamance region of southern Senegal. Just eighteen days after leaving her nest site in the Scottish Highlands she had reached a favourite wintering area for Ospreys from the UK.

Next day Deshar continued another 100 km west, following the course of the Casamance River before roosting in an area of mangroves to the north of the main river channel. She was now just 25 km from the sea and next day she reached the Atlantic coast at around 14:00.  The satellite data then indicates that the young Osprey spent just under an hour fishing in the sea, before landing on the beach, presumably with a catch. This may have been her first meal since arriving in Africa on 10th September, and demonstrates why it is vital for young Ospreys to depart their nest site in good condition, with plenty of stored body fat.

Having crossed the Sahara, Deshar headed south-west to the Casamance region of southern Senegal.

After reaching the Senegal coast, Deshar spent close to an hour fishing in the sea.

One of the problems for young Ospreys when they arrive in prime wintering habitat is that they will often be chased away from the best areas by experienced adult Ospreys who return to the same place each winter and often become territorial over favoured perching and feeding areas.  This perhaps explains why Deshar continued to wander around the coastal mangroves that afternoon and again next morning. In fact the last data we received in this batch showed that during the course of the day on 24th September Deshar headed 60 km north and crossed the River Allahein into The Gambia.  Let’s hope she finds somewhere safe to settle down after her fantastic migration from the Scottish Highlands.

Deishar flew north to The Gambia on 24th September

To see Deshar’s complete migration on our interactive map, click here.

Deshar also features in our latest podcast. Click the link below to listen online.

Sad news from Morocco

Having been present at Lalla Takerkoust, a reservoir situated to the north of the Atlas Mountains in Morocco for just over a week, we began to become concerned about Carr on 23rd September. It was clear from the latest data that either the young Osprey hadn’t moved for at least three days, or his transmitter had become detached. Although the locations we receive are highly accurate, they could not explain what had happened. The only option was to try and find someone who may be able to go and have a look for us.

After a week at the reservoir we became concerned when the satellite data indicated Carr hadn’t moved for three days.

We put out an appeal for help on Monday morning, and within a few hours Adil Boulahia had found two Morocco ornithologists – Karim Roussleon (Moroccan Association for Falconry and Raptor Conservation and member of GREPOM) and Dr Mohamed Radi (Groupe de Recherche pour la Protection des Oiseaux au Maroc (GREPOM) – BirdLife International’s local partner in Morocco) – who were prepared to go and search for Carr. That evening Karim visited the site and found a pile of Osprey feathers at the location we had directed him to. Sadly it was clear that Carr had been predated by a fox or a dog while he had been perched on the ground.

Karim found a pile of Osprey feathers at the last known location of Carr (photo by Karim Roussleon)

Close-up of the feathers (photo by Karim Roussleon)

Carr had obviously been perched on the ground when he was predated by a fox or a dog (photo by Karim Roussleon)

Carr had spent over a week at the reservoir north of the Atlas Mountains (photo by Karim Roussleon)

Although it was clear that Carr had died, Karim was not able to find the transmitter that evening. Mohamed kindly offered to search again on Wednesday, and this time managed to locate it nearby.

It is extremely sad that Carr had died, but the reality is that at least 70% of young Ospreys do not survive the first two years of their life. Many die on their first journey south, while others perish once they reach the wintering grounds. Even though Carr had been flying strongly for two months and had made an excellent migration to Morocco, he was still very inexperienced – and this led to him perching in a place where he was at his of being grabbed by a mammal predator. This is one of the many hazards that young Ospreys face as they migrate south for the first time. In fact one of this year’s Poole Harbour Ospreys suffered the same fate just as it was about to depart on migration at the beginning of this month.

Whilst the outcome is not what we had hoped for, we are extremely grateful to both Karim and Mohamed for their valuable help and assistance this week. This kind of information adds greatly to our knowledge of Osprey migration – and the threats the young birds face as they migrate south for the first time. Sincere thanks to both Karim and Mohamed for their help.

Although Carr has not survived his first flight south, we are pleased that his sister Deishar is now in West Africa. You can check out her latest update here. You can also view the flights of the two birds on our interactive map.

Carr and Deishar also feature in our latest podcast. Click the link below to listen online.

Carr stops-over in Morocco

Having arriving in Morocco just 11 days after leaving the Scottish Highlands on his first migration south, Carr has obviously taken a liking to life in North Africa. After reaching northern Morocco on 11th September, Carr travelled another 400 km next day, flying at altitudes of up to 2000 metres as he headed south. By 18:00 local time he was passing to the east of Marrakesh and that evening roosted on a wooded hillside in the northern foothills of the imposing Atlas Mountains, at an altitude of just over 1200m.

Next morning, as the sun rose, Carr may well have been able to look down from his roost site to Barrage Lalla Takerkoust, a 2 km-long lake, 12 km to the west. It was no sunrise, therefore, that soon after first light, he headed straight there. He remained beside the water for the rest of the day, and, what’s more, he’s still there a week later.

Carr arrived at the lake on the north side of the Atlas Mountains on 13th September

Carr has now been present at the lake for a week.

A look at the spread of Carr’s data points over the last week shows that he has spent most of his time on the shores of the lake, and must be catching fish on a daily basis. He has made one or two longer exploratory flights locally, but returned to Barrage Lalla Takerkoust on each occasion. Stop-overs like this can be very important for young Ospreys like Carr because it will enable him to refine his fishing skills and also put on body fat prior to his crossing of the Sahara. We wonder how long it will be before he sets off across the desert?

Carr flew 400 km through Morrocco on 12th September and is now in the northern foothills of the Atlas Mountains

Carr’s migration to date from northern Scotland

Don’t forget you can follow Carr’s migration on our interactive map. 

Carr also features in our latest podcast. Click the link below to listen.

Deishar crosses the Sahara

When Deshar arrived in Algeria on 10th September, we were concerned that she was much further east than the route favoured by experienced adult Ospreys from the UK. It meant that, if she was to reach the fish rich coastline of West Africa, she would have to make a very long flight across the vast and desolate Sahara.

Fortunately the latest data shows that Deshar is making good progress. The latest update we have – from the evening of 17th September showed that she had almost completed her epic flight across the desert and was in southern Mauritania.

And what a superb flight it has been so far. After leaving her roost site in northern Algeria on the morning of 11th September  Deshar flew 2608 km (1620 miles) over the course of seven days – that’s an average of 372 km (231 miles per day). During this period she maintained a remarkably direct south-westerly heading through Algeria, before crossing into North-west Mali on the afternoon of 14th September and then into Mauritania next afternoon.  She’s well on course to reach the West African coast – and we very much hope that will be the case when we receive the next batch of data from her transmitter.

Deshar flew 2608 km (1620 miles) across the Sahara in seven days

While crossing the Sahara Ospreys roost on the ground, and usually delay the start of their daily flight until thermals star rising. Deshar’s transmitter, which logs her location once every minute as she flies across the desert, shows that, despite her inexperience, she has utilised these thermal updrafts well, sometimes circling up to staggering altitudes of 3400m before opening her wings and gliding forwards until she reaches the next thermal.  This saves valuable energy during a period when she is unable to feed.

By circling up on thermal updrafts and then gliding forward, Deishar saves valuable energy as she crosses the Sahara

You can check out Deshar’s flight across the desert on our satellite tracking map.

Deshar also features in our latest podcast. Click the link below to listen.

Deishar’s first flight south

Deishar set off on migration three day’s later than her brother Carr, but, like her sibling, she has made excellent progress south since leaving Scotland.

Deishar began her migration on 4th September and very quickly made up for lost time. Aided by a tailwind she flew just under 500 km to Cheshire on her first day of migration, flying south through central Scotland, and then across the Solway Firth and Morcambe Bay – which she crossed after dark.

Next morning Deishar was flying again before 06:00, heading powerfully south through Shropshire and then Herefordshire. At 10:16 she was 186 metres above the Severn Estuary and, at 10:50, 550 metres above the centre of Bristol. At 12:32 she headed out across the English Channel from the Dorset coast, west of Abbotsbury. She flew 135 km to Guernsey and then a further 98 km across the sea to the Brittany coast at Saint Brieuc. She was making such fast progress that she had now overtaken her brother, Carr, who arrived and then roosted on Guernsey a few hours after Deishar had passed through. She continued flying for a further 90 minutes after reaching French airspace, before roosting in an area of woodland near Plumeliau.

Deishar arrived in Brittany just two days after leaving the Highlands

Next morning Deishar continued south-west towards the Atlantic coast. Unlike her brother who then flew direct across the Bay of Biscay to Spain, Deishar always kept the coast in sight as she headed south. By 16:48 that afternoon she had flown 275 km and was over Ile d’Oleron just to the south-west of La Rochelle. She continued south over the River Gironde and then settled to roost in a forested area near the village of Naujac-sur-Mer, around 50 km north-west of Bordeaux.

Deishar (red line) kept to the coast as she flew south through France, whereas her brother (yellow line) crossed the Bay of Biscay to Spain

Next morning Deishar headed south-east away from the coast and towards the Pyrenees. She flew just under 200km before roosting beside the River Adour. Although she arrived too late to fish that evening, the data indicates she may have caught her first fish since leaving Scotland, soon after first light the next morning.

Deishar roosted beside the River on the evening of 7th September, and the data suggests she fished in the river the next morning.

Deishar resumed her journey at around 11:00 on 8t September and reached the Pyrenees two-and-a-half hours later. Her satellite transmitter – which logs her location once every three minutes – showed how she flew picked her way through the imposing mountains to avoid crossing the highest peaks. Nevertheless she still reached a maximum altitude of over 2564 metres above sea level as she flew through the mountains.

Deishar reached a maximum altitude of 2564 m as she crossed the Pyrenees

Once clear of the mountains, Deishar continued south until 19:44 local time when she settled to roost beside the River Ebro, 10 km east of  Zaragoza. She had flown 250 km during the course of the day.

Having reached northern Spain, Deishar showed no signs of letting up and she made the most of excellent flying conditions on 9th September, soaring and gliding through Aragon, sometimes reaching altitudes in excess of over 3000 metres. She continued flying until 20:00 by which point she had covered a further 300 km and was now 45 km south-west of Valencia.

Deishar made the most of excellent thermal conditions as she soared south through Spain, climbing on thermal updrafts and then gliding forwards.

Next morning Deishar continued on the same southerly heading and at 14:00 local time she reached the south-east coast of Mercia, south-west of La Manga and headed across the sea. The crossing to Africa is much further here than the Strait of Gibraltar where many Ospreys cross, but Desihar made light work of it, flying 210 km across the sea in four-and-a-quarter hours.

Deishar made a 200km sea crossing from Spain to Algeria.

Having reached Algeria, Deishar continued flying for a further 60 km before roosting on the edge of the town of Relizane. Deishar is now much further east than her brother, Carr, and will have a longer crossing of the Sahara unless she makes a drastic turn to the south-west. Her transmitter works through the mobile network and so we may not receive any further updates from her until she is across the Sahara. Let’s hope she makes it – but it is a difficult journey for you Ospreys on their first autumn migration.

Deishar has reached Algeria just seven days after leaving her nest in the Scottish Highlands.

To see a map of Deishar’s journey so far, click here.