Sedge Warblers and evening ringing

Sedge Warbler migration is slowing down but Reed Warblers may still be attending fledged young therefore we will seeing them for a while longer.

Sedge Warbler - Diane Williams

As dusk approaches we have been opening a couple of mist nets for Swallows and Sand Martins, though Yellow Wagtail along with Pied and White  coming to roost and a hunting Hobby have added to the evening.

Evening ringing in the reeds

Sedge Warblers processed July to August 

Teifi Marshes

2026   519 total  474 new

2025   629 total  546 new

Cors Caron

2026 76 new

2025 86 new

Though captures are down on the previous year we believe a successful early breeding season, followed by prolonged good feeding weather encouraged birds to move early. Fat scores and weight seem to be slightly  lower this season, maybe due to not depositing fat, just feeding as they move in the exceptionally good conditions.

Juvenile Sedge Warbler

Overall, the recoveries below  reinforce established migration corridors linking Wales with western France, Cornwall, and Dorset, and demonstrates the high mobility of Sedge Warblers during July and August.             

Movements of Sedge Warblers in July and August

Sedge Warbler 9108551 

13/08/2022 Treogat, Finistere, France 01/07/2026 Teifi Marshes  1418 days 467km N

Sedge Warbler BXF0605

24/07/2025 Carey Floodplain, Dorset  27/07/2026 Teifi Marshes  368 days 233km NW 

Sedge Warbler BJD8212

31/07/2024 Trimley Marsh, Suffolk  29/07/2026 Teifi Marshes 728 days 405km W 

Sedge Warbler  9343538

25/08/2023  Treogat, Finistere, France 06/05/2026 Teifi Marshes  985 days 467km N

Sedge Warbler 10179216

24/07/2025 Donges, Loire-Atlantique, France 03/05/2026 Teifi Marshes 283 days 562km NNW

Sedge Warbler BEP3406

09/08/2026 Nanjizal, Cornwall 16/08/2026 Teifi Marshes 7 days, 236km NNE

Sedge Warbler BCK8690

23/07/2026 Cors Caron 09/08/2026 Clanfield, Oxfordshire 17 days, 171km ESE

Sedge Warbler BKN8888

31/07/2026  Teifi Marshes 07/08/2026 Carey Floodplain, Dorset 7 days, 232km SE

Sedge Warbler   BZK4348

17/08/2026   Teifi Marshes   20/08/2026 Carey Floodplain, Dorset 3 days 232km SE

Sedge Warbler   BHH5582

22/08/2025 Teifi Marshes  11/07/2026 Kinneil Lagoon, Falkirk, Scotland 323 days 442km N

A couple of Reed Warbler movements. More on Reed Warblers in a later post - a RAS (Retrap Adult Survival) study species.

Reed Warbler BLJ7672

11/07/2026 Oxwich Marsh, Swansea 02/08/2026 Teifi Marshes  22 days 67km NNW 

Reed Warbler BBB3358

15/05/2025 Teifi Marshes  16/07/2026 Cors Ddyga, Anglesey 427 days 130km N 

Only one movement involved Cors Caron, with a Sedge Warbler travelling 171 km ESE to Oxfordshire — consistent with the site’s typical eastward mid summer pattern. 

This bird was re-encountered by our ringing buddies in the WOFBP (West Oxfordshire Farmland Bird Project).  A Group we visit several times each winter to assist with farmland winter feeding projects.

Evening activities mentioned earlier have resulted in  377 Swallows, 11 Sand Martins plus a few wagtails ringed. As the Swallow passage has decreased we now focus on wagtails - with a particular interest in White Wagtails. 

With 5 recoveries of our ringed  White Wagtails in Iceland - a real focus ! 

A fat 4 , 31.5 g adult male White Wagtail the highlight of the latest session on the 1st September.

(Rich D and Wendy J)

Storm Petrels - Strumble Head

Our highest total with 208 new Storm Petrels ringed in 12 visits to Strumble Head  between 15th June and 7th August this year - 2026. 

We re-encountered 28 birds wearing rings fitted elsewhere and 11 birds ringed at Strumble were re-encountered elsewhere. This number is likely to rise when Storm Petrel data at some other sites is submitted to the BTO. 

We processed four Storm Petrels ringed by us, two from 2025, two from 2024.

A ringing demonstration in the Strumble Head lookout (Stephen Hyam)

The Strumble Head catching and processing  sites are well structured, and we use the site with permission of the Pembrokeshire Coast National Park.  This enables us to offer new experience for trainees, ringing demonstrations to formal and informal groups, and hosts mist net endorsement assessment.

Storm Petrel Movements Involving Strumble Head, 2024–2026

Storm Petrel ringing and recovery data from 2024–2026 highlight Strumble Head as a significant movement hub within the Celtic Sea and Irish Sea. Birds encountered at Strumble originate from a wide geographical spread including Cornwall, Ireland, Bardsey, Gwynedd, Lundy and, most prominently, Skokholm Island. Conversely, birds ringed at Strumble disperse widely across the western seaboard of Britain and Ireland.

Storm Petrel movements from Strumble

Storm Petrels were re-encountered at Strumble from Skokholm, Porthgwarra, Little Saltee, Porth Iago, Cape Clear, Bardsey, Lundy, 

Movements to Strumble

Recoveries at Strumble Head of Birds Ringed Elsewhere

A total of 28 birds ringed away from Strumble were subsequently encountered at the site. These movements fall into two broad categories: long range Celtic Sea crossings and short range movements from Skokholm Island.

Long range movements

Several birds made substantial crossings of the Celtic Sea or Irish Sea before arriving at Strumble:

• Cape Clear Bird Observatory, Cork → Strumble Head One bird moved ENE across the Celtic Sea after “361 days 313km ENE”.

• Little Saltee, Wexford → Strumble Head A direct eastward movement recorded after “374 days 104km E”.

• Bardsey Island → Strumble Head Two birds travelled SSW into Pembrokeshire after “331 days 84km SSW” and “351 days 82km SSW”.

• Porth Iago, Gwynedd → Strumble Head A similar SSW movement occurred after “323 days 94km SSW”.

• Porthwarra, Cornwall → Strumble Head A strong northward movement recorded after “325 days 224km N”.

• Lundy Island → Strumble Head A rapid movement northwards after only “6 days 95km NNW”.

These recoveries demonstrate Strumble Head’s position as a key interception point for Storm Petrels moving through the Celtic Sea basin.

Short range movements from Skokholm Island

The majority of recoveries originate from Skokholm Island, only 40 km SSW of Strumble Head. These movements show a highly consistent pattern:

• Distance: 40 km NNE

• Intervals: from 0–12 days (e.g. “0 days 40km NNE”, “5 days 40km NNE”, “12 days 40km NNE”)

• Longer intervals: up to “683 days 40km NNE” and even “3616 days 40km NNE”

Recoveries Elsewhere of Birds Ringed at Strumble Head

A total of 11 birds ringed at Strumble were later encountered away from the site. These movements show broad dispersal across the Celtic Sea, Irish Sea, and northern Britain.

Movements to Cornwall

The most frequent outbound direction is SSW towards Cornwall:

• “710 days 224km SSW”

• “1088 days 224km SSW”

• “18 days 224km SSW”

• “16 days 224km SSW”

These mirror the inbound movements from Cornwall to Strumble.

Movements to Ireland

Two birds crossed westwards to Cork:

• “20 days 271km W”

• “1098 days 271km W”

Movements to Lundy

A rapid SSE movement was recorded:

• “5 days 95km SSE”

Movements to Scotland

Two notable long range movements northwards:

• Porthknockie, Moray – “38 days 645km NNE”

• St Abbs Head, Scottish Borders – “30 days 472km NNE”

• Eilean Nan Ron – “731 days 727km N”

Movements to Isle of Man 

• Calf of Man – “35 days 225km N”

These demonstrate substantial northward dispersal into the Irish Sea and beyond.

A summary of  re - encounters to date.

(to and from Strumble)

1. Strumble Head as a Celtic Sea crossroads

Birds arrive from multiple directions—Cornwall, Ireland, Bardsey, Gwynedd, Lundy and Skokholm—highlighting Strumble’s position on a major Storm Petrel movement corridor.

2. Strong Skokholm–Strumble linkage

The repeated 40 km NNE movements, often within 0–12 days, show Strumble Head as a reliable interception point for Skokholm birds during the breeding season.

3. Bidirectional Celtic Sea movements

Birds ringed at Strumble disperse widely:

• SSW to Cornwall

• W to Cork

• SSE to Lundy

• NNE to Scotland

• N to Isle of Man and Eilean Nan Ron

4. Rapid movements

Several birds moved between sites in under 10 days, demonstrating high mobility during the breeding period.

5. Long-term fidelity

Multi year intervals (e.g. “1088 days”, “1098 days”, “3616 days”) indicate long-term survival and repeated use of the Celtic Sea region.

Strumble Head continues to function as both:

• A major interception point for Storm Petrels dispersing from Skokholm, Bardsey, Cornwall, Ireland and Lundy.

• A launch point for birds moving SSW to Cornwall, W to Ireland, NNE to Scotland, and N to the Isle of Man and Eilean Nan Ron.

These movements reflect a dynamic and wide ranging Storm Petrel population, with Strumble Head positioned at a key junction of regional Storm Petrel traffic. 

(Rich D and Wendy J)

A recent Linnet movement..

A few words from Chris  following the latest movement of a Linnet, ringed at our Linnet RAS study site in Norh Pembs to Northern Ireland.

Linnet BEE7397

Ringed  27/03/2025 Moylegrove

Re-encountered   12/08/2026 Shamrock Island. Kilinchy, Down, NI 502 days 273km NNW

Ringed at the end of March, when most if not all of them seem to be passage birds; our breeders arrive a week or two later. 19.3 and 19.5 gm are at the very top end of the weight range for females, so it will have been carrying a good store of fat when ringed and when re-encountered, suggesting that it was already on its way back to its winter quarters when encountered on this island in Strangford Lough. Very nearly all our breeders have already departed by mid-August. So I'm thinking that yes it's a movement to N.Ireland, but via somewhere further north. - Chris Jones.

Linnet movements to N Ireland and North Ronaldsay

We have added the movement of a different Linnet, ringed at our previous Linnet RAS study site in Aug 2018 and retrapped on North Ronaldsay in  May 2024 .....2090 days 815km. 

A little research suggested this was the longest intra UK movement by a Linnet..

Chris is writing an end of season Linnet summary with RAS study details and other movements..

(Rich D and Wendy J)