Storm Petrel Movement Report 2025
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.
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.
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.
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.
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).
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.
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)
