Cory's Shearwater sighting could be an Arran first

Cory’s Shearwater is a rare vagrant in the Firth of Clyde. They breed across the Atlantic archipelagos with the Azores, Canaries, Madeira, Salvagems and Berlengas all having breeding colonies.

 

Birds start to leave these colonies in August, with many heading for the Bay of Biscay. Some years there are thousands there. Some head further north into UK waters, but numbers vary depending on weather conditions and some years there are hardly any reports.

 

Cory’s Shearwaters are oceanic birds spending the winter off the coasts of South America and South Africa before returning to their breeding colonies in March.

 

It is during the late summer months that this large brown and white shearwater, with its languid flight, visits our waters. Cory’s Shearwater is large, 45 to 56cms (18 to 22 inches) in length and with a wingspan of 112 to 126cms (44 to 50 inches).

 

It has brownish-grey upperparts, white underparts and a yellowish bill. It lacks the brown belly patch, dark shoulder markings and black cap of the other vagrant large shearwater, the Great Shearwater. The two species
also fly differently. Cory’s Shearwater flies with long glides and always with wings bowed and angled slightly back, unlike the stiff, straight-winged flight of the similarly-sized Great Shearwater.

 

On that late August evening, Nick Giles and his father Mike, both experienced birdwatchers, were on the ferry to the mainland.

 

Nick said: “I was sitting with my parents on the port side of the enclosed main deck of MV Alfred which has large windows. We were sitting at a window seat. I was facing forward and my father was opposite me facing backwards. I was looking out for Manx Shearwater when a large, heavy-looking Shearwater slowly glided past the boat at eye level to me, making just a couple of lumbering wing beats. The very light coloured and long Shearwater’s beak and the Shearwater shaped head were noticeable to me and it seemed pure white underneath with no dark markings on the belly. I grabbed my camera and headed up to the upper deck to see if I could see the bird again and photograph it.

 

"I didn’t see it again but there were plenty of Manx Shearwater viewed for the next 20 minutes as well as an
European Storm Petrel.”

 

You get a sense of the excitement. The image illustrating this article matches the image in Nick’s eye but unfortunately it was not captured on Nick’s camera. There was much discussion with both observers drawing on their previous experience. Nick had seen Cory’s Shearwater with a local guide in Portuguese waters as well as similar shearwaters in pelagic trips in Australia.

 

They were 100 per cent certain they had just seen a Cory’s Shearwater and have submitted the appropriate completed form to the Scottish Birds Rarities Committee (SBRC) for its consideration and hopefully ratification of a first Arran record.

 

To date, there have been no confirmed Arran records. Although reports of Cory’s Shearwater have appeared in previous Arran annual bird reports in 1984, 1997 and 2012, these were called "possible" and no forms were submitted to the SBRC for ratification.

 

There have been no accepted records from Clyde/Clyde Islands but there have been 11 accepted Ayrshire records, all from the last century, and nine accepted Argyll records including two this century, one at Machrihanish in 2002.

 

This August, the weather was conducive to driving Cory’s Shearwater north after leaving their breeding grounds with a series of Atlantic fronts, some storm force, moving through.

 

An examination of the national Bird Guides website shows in August for Scotland 39 records - as yet none confirmed. There were 15 from the Outer Hebrides; eight from Fife/Lothian; five from the Northern Isles with, closer to home, one off Dumfries and Galloway on August 23 and one off Argyll on August 30.

 

What about the Arran record on August 27? We will have to wait for the deliberations of the SBRC. I will keep you posted.

 

Please send any bird notes with “what, when, where” to me at Kilpatrick Kennels, Kilpatrick, Blackwaterfoot, KA27 8EY, or email me at jim@arranbirding.co.uk. I look forward to hearing from you.

 

For more information on birding on Arran purchase the Arran Bird Report 2023. You can also visit www.arranbirding.co.uk/index.html