Cory's Shearwater (Calonectris borealis)Where and when to see it in the UK
Status not yet classified · reporting peaks August · Petrels, Shearwaters, and Diving Petrels · BOU category AF
Peak months
Contains OS data © Crown copyright and database right 2026 (grid squares, place names from OS Open Names). Northern Ireland place names: OSNI Open Data, OGL v3.0. County and country boundaries: Office for National Statistics, Open Government Licence v3.0. Coastline: Natural Earth. Bird records from the data partners listed here.
Cory's Shearwater has been recorded in 81 of the 2,971 10 km squares covering UK land (3%) in records to 2026. Its strongest squares are in England, Scotland and Wales. Reporting peaks in August.
Conservation status: Least Concern (IUCN Red List, LC)
View on the IUCN Red List- Very high
- 17% or more of visits
- High
- 4% to 17%
- Moderate
- 1% to 4%
- Low
- under 1%
- Surveyed, not recorded
- at least 20 qualifying visits, no record
- Insufficient records
- too few visits to say
- Lighter fill
- Few visits, lower confidence
- Small dot
- Occasional: a single record, or out of season
Relative to this species' best squares (how classes are calculated)
Seasonality
| Month | Relative to peak | Share of visits | Typical class |
|---|---|---|---|
| January | 0% | <1% | Insufficient records |
| February | 0% | <1% | Insufficient records |
| March | 0% | <1% | Moderate |
| April | 0% | <1% | Insufficient records |
| May | 0% | <1% | Low |
| June | 1% | <1% | Moderate |
| July | 26% | <1% | Very high |
| August | 100% | <1% | Very high |
| September | 31% | <1% | Low |
| October | 46% | <1% | Very high |
| November | 3% | <1% | Low |
| December | 0% | <1% | Insufficient records |
Squares with the highest reporting rate in August
| Square | Where | Share of visits | Class |
|---|---|---|---|
| SW20 | Sea, off Cornwall | 100% | Very high |
| SW83 | Cornwall, England | 100% | Very high |
| SW91 | Sea, off Cornwall | 100% | Very high |
| SX32 | Sea, off Cornwall | 78% | Very high |
| SV70 | Sea, off Isles of Scilly | 65% | Very high |
| SR69 | Sea, off Pembrokeshire | 57% | Very high |
| SW01 | Sea, off Isles of Scilly | 56% | Very high |
| SW00 | Sea, off Isles of Scilly | 55% | Very high |
| SW21 | Sea, off Cornwall | 53% | Very high |
| SW11 | Sea, off Cornwall | 50% | Very high |