Thursday, August 2, 2012

Another new Atlantic Shearwater to worry about?

Once upon a time there were just 5 species of Shearwater we had to worry about in the North Atlantic (Great, Cory's, Sooty, Manx, Audubon's) and life was good.  Then along came some splitters and pointed out that the situation was probably a tad more complex than we had thought, leading to Yelkouan Shearwater and Balearic Shearwater.  More recently, we got to start fretting about Cape Verde Shearwater, and the one I missed this Spring off Long Island (while I was in the Adirondacks, feeding the mosquitos and not seeing Spruce Grouse) still rankles a bit.  Now, it looks as though Scopoli's Shearwater (the Mediterranean breeding populations of Cory's Shearwater) is set to become a species too.  So, in short, no more off-the-cuff Cory's Shearwater IDs and each bird now has to be studied to tease apart these sister species.

Went out on the CRESLI (Coastal Research and Conservation Society of Long Island) Whale-watching trip on the Viking Fleet yesterday.  A number of New York birders including Corey Finger, Richard Fried and Shaibal Mitra initially planned to go, but they dropped out one-by-one leaving just me, Jacob Drucker and Lila Fried boarding the boat at 9:30am.  I rarely go out with this crew because they are primarily focussed on Whales and Dolphins, stray often into Rhode Island waters, and don't tend to go very far offshore.  Having said that, it is a cheap way to get out on the water and for only $75, you are at least out there 10-30 miles South of Long Island, and who knows what might show up.

As it happens, there wasn't that much to see bird-wise, or whale-wise for that matter, but we did eventually bump into a pod of about 60 Short-beaked Common Dolphins which made the Whale-watching part of the trip a big success for the, mostly French, tourists on board.   A Kemp's Ridley-Turtle was also notable, albeit seen briefly, as were a couple of breaching Basking Sharks.

Short-beaked common Dolphin (2 shots)

Back to the birds and we worked pretty hard all day, picking up a single Parasitic Jaeger, 95 Wilson's Storm-Petrels, 15 Great Shearwaters and about 20 "Cory's Shearwaters".  Within the Cory's, some were indeterminate, most were the borealis ssp. but one bird looked pretty good for a SCOPOLI'S SHEARWATER, showing lots of white on the primaries.  I don't think it's a slam-dunk, the white is not as crisp as some of the illustrations/pictures I've seen, but it was at least intriguingly different and we reported it as a "possible" Scopoli's, putting photos out there for comment.

'borealis' Cory's Shearwater - note all dark primaries.

Possible Scopoli's Shearwater (2 shots) - note pale bases to primaries.

Scopoli's is supposed to also be smaller, lighter in build, and paler than Cory's and while it did seem to be a lightly-built bird, paleness is really difficult to discern when so many of the Cory's were in molt and looking pretty scruffy.  Still, an interesting bird, and no doubt one that we'll all be getting used to (expert at) differentiating if indeed it does get split.

Update:  as of September 2012, the BOU has split this species.  Who knows whether the AOU (or Clements, which matters more for World Listers) will follow suit.

1 comment:

  1. Man, I wish I could have got out on the water...I can't do the September trip either so it looks like no pelagics for me this year.

    And, for what it's worth considering how little experience I have with shearwaters I have, it looks good for a Scopoli's to me.