Cory's Shearwater (Calonectris diomedea)
Above and below: Photos taken in Maryland waters on a pelagic trip out of Lewes, Delaware (8/28/2004).
Below: A Cory's Shearwater (borealis) off Cape Hatteras, North Carolina (5/28/2011). Note the difference in underwing pattern and bill size between this bird and the following Scopoli's Shearwater (diomedea).
Below: A Scopoli's Shearwater off Cape Hatteras, North Carolina (5/29/2011). This is the Mediterranean form (diomedea) of Cory's Shearwater, which is a candidate for a future split. Note how the white extends into the dark primaries and its smaller bill.
Below: One of six Cory's Shearwaters observed from the Judith M out of Ocean City, Maryland (6/26/2011).