Friday 2 February 2024

Grampian Ospreys in the Sun

 Ian Francis, Ewan Weston, Jenny Weston

Between 17 and 21 pairs of Ospreys are known to have nested in Aberdeenshire over the past eight years, though we believe pairs are missed. We know that some of our fledged youngsters are breeding elsewhere, so the movement away of potential recruits could influence our local population. In 2023, we only located 17 active nests, with pairs not present at three long standing sites and no new fully occupied nests found. There were rumours of pairs at a couple of other sites, but these were not located. Breeding productivity was a little above average though, at c.1.5 chicks fledged per occupied nest, but outcomes were uncertain from at least one site.

Six chicks were ringed in 2023 and in total, since 1993, GRG has ringed 248 Osprey chicks. Over that period, there have been 133 resightings or recoveries of at least 58 individual chicks. Most are now marked with blue plastic darvic rings with white digits (left leg) and many are now photographed or captured on nest cameras. Technology has certainly improved the reporting rate! 

An interesting set of sightings of one young bird from near Monymusk came last year, 2023. It was one of a brood of three chicks, ringed by a GRG team led by Ewan Weston on 10 July. It probably fledged around the end of July and hung around for a short while. However, from 26 August to 16 September it was near London, and was appreciated by many tens of people in that time. An easterly migration route for our birds is relatively unusual, as more often they are seen in south-west England, particularly Cornwall and Devon.
Osprey brood, Donside, 10.7.23. A chick (Blue 256) fledged from here migrated south via London, spending a week there. Photo: Ewan Weston

Osprey Blue 256, from Donside nest, Bowyers Water, Lee Valley , London 31.8.23. Photo: Stuart Fox

Another 2023 Osprey nest nearby also had a brood of three, all duly ringed. One of the chicks from here was seen by Jean-Marie Dupart on 23 January 2024 at the Karone Islands, in Casamance, Senegal (12 degrees north).  

Osprey brood, Donside, 10.7.23. A chick fledged from this nest (ring 253) was seen in Senegal in January 2024 (see below). Photo: Ewan Weston

Osprey Blue 253 photographed in Senegal by Jean-Marie Dupart on 23 January 2024.

Osprey Blue 253 photographed in Senegal by Jean-Marie Dupart on 23 January 2024

This is not the group’s first Osprey recovery from Senegal – in fact, it’s the sixth. We’ve also had recoveries from The Gambia (three), Ghana and Guinea-Bissau (one each). The sunny climes of west Africa are clearly the place to be in winter for our birds, and this is not just true of juveniles, which spend their first full year there, but also returning adults. And their predilection for winter sun also extends to many sightings in south-west Europe – either on passage or increasingly, wintering, with Portugal a popular resort and Spain a close second.

Here's another Grampian Osprey, blue JF1, also from a nest in Donside in July 2017 (another  brood of three), photographed in Senegal by Jean-Marie Dupart again, in December 2023. This bird is obviously paddling to keep cool or pretending to be a wader! 

JF1 in Senegal, Jean-Marie Dupart
JF1 is a bird with a history – it has been a regular in Cornwall on passage (seen first in the year of its birth heading south), plus near Edinburgh, and intriguingly, it was seen in summer in Aberdeenshire, so it must be a local breeder, though we don’t’ know where – somewhere on the Deveron, probably. It may well have been in Senegal every winter since then.

Sightings of Osprey JF1 since 2017:
Devoran Creek, Cornwall, 4.9.17
Devoran Quay, Cornwall 18.9.17
Tyninghame, Lothian, 15.08.19
Rothiemay, Aberdeenshire 1.6.20
Restronguet Creek, Cornwall, 9.9.2021
Restronguet Creek, Cornwall, 15.9.2022
Senegal, 9.12.2023.

Osprey chick blue JF1 in its Donside nest, July 2017. Photo: Ewan Weston

We now know quite a lot about where our Aberdeenshire ospreys go in winter and where they pass through. Although we are ringing fewer birds than previously, it is important to keep a sample going every year. Climate change may well mean that birds winter further north, and we also need to understand how our Aberdeenshire-reared birds are seeding new breeding areas further south in the UK. We would rather our local population increased, but we are also happy to see them settled further south, gradually building overall numbers – and fuelling the continued search for Osprey winter sun!

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