Storm Petrel movement report 2025

 Storm Petrel Movement Report 2025

Summary of Recoveries and Movements Involving Strumble Head and Associated Sites

In 2025 between June 19th and July 30th we processed 115 Storm Petrels at Strumble Head, Pembrokeshire, of which 109 were new birds. This is lower than the 2024 total of 162.

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1. Overview

The dataset documents 32 individual Storm Petrel movements involving Strumble Head and a network of colonies and coastal observatories across the Irish Sea, Celtic Sea, and eastern Atlantic. Movements range from short‑distance local exchanges (40–100 km) to long‑distance dispersal events exceeding 1,600 km. The records highlight Strumble Head as a major node in regional Storm Petrel movements, with repeated exchanges between Welsh, Irish, English, and Portuguese sites.

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2. Key Movement Patterns

2.1 Dominant Local Movements

The most frequent pattern involves Strumble Head ↔ Skokholm Island, with 15 movements recorded.

• Distance: consistently 40 km
• Direction: SSW (to Skokholm) or NNE (to Strumble)
• Time intervals: 2 to 743 days
• These movements indicate strong short‑range connectivity between the two Welsh sites, likely reflecting foraging movements. 

2.2 Movements to Bardsey Island

Five birds moved between Strumble Head and Bardsey Island, all travelling 84–86 km NNE.

• Durations: 3–26 days
• These short‑interval movements suggest regional dispersal within the northern Irish Sea.

2.3 Movements to Lundy Island

Two movements link Strumble Head and Lundy Island (95–97 km SSE).

• Durations: 40–378 days
• These represent medium‑range movements within the Bristol Channel region.

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3. Long‑Distance Movements

3.1 Ireland (Cork and Wexford)

Several birds travelled between Strumble Head and southern Irish sites:

• Galley Head (271 km W) – 9 days
• Cape Clear (312 km W) – 25 days
• Little Saltee, Wexford (104 km E) – 46 days
  These movements demonstrate cross‑Celtic Sea travel.

3.2 Isle of Man

One bird moved from Calf of Man → Strumble Head:

• 225 km S over 340 days

3.3 Portugal

The most distant movement in the dataset:

• Strumble Head → Pomta de Almadena, Portugal
• 1688 km S over 339 days
  This record highlights the species’ capacity for extensive Atlantic dispersal.

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4. Notable Individuals

• 2739422 & 2739428
• Both moved from Strumble Head to Skokholm Island after 743 days, the longest intervals recorded.
• 2788730
• Recorded twice in the same season:
• Strumble → Bardsey (24 days)
• Strumble → Skokholm (33 days)
• Demonstrates multi‑directional dispersal within a short timeframe.
• 2787269
• The only bird recorded travelling to Portugal, representing the longest movement (1688 km).

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5. General Interpretation

• Strumble Head functions as a central hub for Storm Petrel movements in the region, with birds dispersing in all directions.
• The majority of movements are local (40–100 km), consistent with foraging and short‑range colony interchange.
• A smaller number of medium‑range movements (100–300 km) link Wales with Cornwall, Wexford, and the Isle of Man.
• Long‑distance movements (>300 km), this demonstrates the species’ ability to traverse large sections of the northeast Atlantic.
• The presence of multi‑year intervals (up to 743 days) suggests repeated site fidelity or re‑encountering of individuals across seasons.

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6. Conclusion

The dataset provides a valuable snapshot of Storm Petrel mobility across the Celtic Sea and adjacent waters. The strong clustering of movements around Strumble Head and Skokholm Island underscores the importance of these sites for monitoring regional population dynamics. Occasional long‑distance recoveries, including the movement to Portugal, highlight the broader Atlantic context of Storm Petrel ecology.

(Wendy J and Rich D)