The Start of new Osprey Dynasties

British migratory Ospreys have many challenges on their journeys to and from West Africa, so it was very encouraging, earlier this month, when the young male (colour ring blue 22) returned to Poole Harbour and paired up with his mate, blue CJ7. He had first returned last May as a two-year-old, too late to breed, but with plenty of time to establish a pair bond with CJ7. Blue 22 had already met this female when he was released from the hacking cages in 2019, as part of the translocation project we are running with Birds of Poole Harbour, under licence from NatureScot. That was CJ7’s third summer in the area, having been seen at Poole Harbour for the first time in August 2017. The two birds looked very settled once they were reunited this spring, and on Saturday we were delighted that CJ7 laid the first egg. You can watch the nest live via the Birds of Poole Harbour webcam.

022(left) and CJ7 looking down into the nest at the newly-laid egg on Saturday

We collected blue 22 from nest B01, not far from Roy’s home in Moray, on 11th July 2019. He was one of a brood of two and in excellent condition – 1500g is a good weight for a male nestling. Tim and Ian Perks drove south with the eleven young ospreys on 12th July. You can find out more by listening to one of the podcasts we made in 2019.

The team at Poole Harbour had built new hacking cages at a secluded location and all 11 young birds thrived on a diet of fresh trout.  Blue 22 was released on 4th August and after four weeks of feeding up on fresh fish, set off on his migration on 1st September.  Two others also started their migrations on the same day. 

That first migration is crucial, and so is the first winter when young Ospreys are often bullied away from the best feeding areas by the wintering adults. They usually remain in West Africa (or Iberia if they have only migrated that far) for the whole of their second calendar year and this gives them the opportunity to get established at a specific site, before the older birds return in the autumn.  If they prove to be winners in the Ospreys’ world then they could return to the same place each winter for two decades or more.

Blue 22 may have started with an advantage for he came from eyrie B01. The oldest and most used nest in Moray – first established in 1966 when there were only two other pairs – both in Strathspey. Most northern Ospreys know this clump of old trees – it’s a favoured eyrie – for them and for us. The female Logie bred here, the first Osprey we tracked with state-of-the-art GPS transmitters in 2007. Morven took over from her in 2008 and wintered in Mauritania; 15 years later she is still breeding in Moray although unlike most Ospreys she has moved nest four times. Satellite tagged males Nimrod and Yellow HA also bred here – it’s a special place. 

Blue 22’s father is unringed but distinctively very white breasted – he kicked out the resident male in 2016 and reared three young. Next summer there were three young, then two young for two years, but in 2020 the pair lost the brood when very small. Last year, he failed to attract a mate so instead he built an extra nest in the big pine next-door – the location on the original 1966 nest when the tree was alive. This year he’s attracted mate and a check and a check this morning showed the female incubating their first egg and her mate perched close by preening. So this year he’s just behind his son – yet 500 miles apart.

Meanwhile what about blue CJ7’s pedigree? She was one of two chicks to fledge from a nest known as Site K near Rutland Water in 2015. Her mother, 00(09) fledged from the Site B nest in Rutland in 2009 and is the daughter of a male osprey 03(97) who was the first transloctated Osprey to breed at Rutland Water and raised a total of 32 chicks between 2001 and 2015. Colin Crooke and Roy collected this young Osprey on 11th July 1997 from a regularly used eyrie near Dornoch in Sutherland. 03 was part of the second cohort of young Ospreys translocated to Rutland Water. CJ7’s father, 06(09), fledged from the Site O nest in Rutland in 2009 and was an offspring of a translocated male 06(00) that Roy and Bob Moncrieff collected from a nest in Strathspey on 10thJuly 2000. That bird’s father, and thus CJ7’s great-gradfather was orange/black SB – one of three young ringed by Roy at the RSPB’s famous Loch Garten nest in 1993. 

CJ7 is the granddaughter of translocated Osprey 03(97), who raised 32 chicks at Rutland Water between 2001-15 (photo by John Wright)

CJ7 has never been seen back in the Rutland Water area, but that is not surprising, because females often disperse to join other Osprey populations. CJ7 was first identified at Poole Harbour by Tim on 8th August 2017. That day she was seen interacting with the first cohort of translocated Ospreys who had just been released. She has continued to return each summer since, clearly encouraged by the presence of young Ospreys in the area.  In 2019 she paired up with a two year-old translocated male, but sadly he failed to return the following spring. Now, finally, she is breeding for the first time, with 022.

 As the years have passed we have got to know individual Ospreys for many years, while others are never seen again after they depart on their first autumn migration. Longevity and breeding success involves luck and being in the right place at the right time. Surviving the early years in Africa and on migration, then finding a good nest site and a successful partner. A female needs to be bold and strong to defend her eyrie from all intruders, to protect her young and to get as much fish as possible into her brood; and her mate needs to be dominant at the fishing grounds and a very skilled fisher. That’s the essence of a being an Osprey pair that lives long and creates a dynasty. Let’s hope CJ7 and 022 have that luck and those skills, and help to re-establish the ‘mullet hawk’ back on the South Coast of England for the first time in more the two centuries. We are proud to work with the Birds of Poole Harbour team, aiming to restore a new dynasty of Ospreys on the coasts of the English Channel.

Roy Dennis and Tim Mackrill