2024 split
Cory's Shearwater split: Cory's and Scopoli's
In 2024 Cory's Shearwater became two species, Cory's Shearwater and Scopoli's Shearwater. Both are seen at sea off the US East Coast.
Updated
What changed
Nests on islands in the eastern Atlantic, such as the Azores and the Canaries. The more common of the two off eastern North America.
Nests on islands in the Mediterranean. Seen less often off eastern North America.
Who decided, and when
- American Ornithological Society (AOS): the 65th Supplement to its Check-list of North American birds
- American Birding Association (ABA): added Scopoli's Shearwater to the ABA Checklist
- eBird and the Clements Checklist: its 2024 taxonomy update
- AviList, the shared world checklist: agrees, with the same names
Which one did you see?
Look under the wing. Scopoli's shows more white there, reaching out toward the wingtip; on Cory's the outer flight feathers are dark below.
Scopoli's is also a little slimmer, with a thinner bill. Photos help a lot.
What it does to your list
If you have seen both, and your records say which, your total goes up by one.
If your old sightings just say “Cory's Shearwater”, they may not say which one you saw. When eBird can't tell which of the new species an old record was, it keeps the sighting as a “one or the other” record. Those stay in your records but don't count as a species.
Check your own list. Drop your eBird download or type your birds: the free checker shows which of them this and other recent changes touched.
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