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)