Cory’s Shearwater Seasonal Occurrence & Geographic Distribution

Cory’s Shearwater Calonectris diomedia

Status: Rare to fairly common in spring & summer, common in early fall in offshore Gulf of Mexico waters in summer and fall. Although both subspecies, C.d. borealis (Atlantic Cory’s) and C.d. diomedia (Scolopi’s Shearwater) have been documented off the Lower Coast. Photographic evidence suggests C.d. diomedia is the predominate subspecies.  Best months are August through October. Sometimes seen from land at South Padre Island or Boca Chica.

Habitat: offshore and pelagic waters of the Gulf of Mexico.

Similar Species: Cory’s Shearwater most closely resembles Greater Shearwater. Cory’s differs from Greater by having a yellow bill, lack of contrast in crown, solid grayish brown nape, and a clean white underwing pattern. By contrast, Greater Shearwater has a black bill, dark cap, distinct white collar, and dark markings on underwing.

© Copyright  Brad McKinney  31 October 31, 2004 (Status updated by Garett Hodne Nov 2014)


The graph below shows the number and date of all Cory’s Shearwater sightings on all Texas Pelagics from 1994 to 2014:

COSH Graph


This map shows the geographic distribution of Cory’s Shearwater sightings (orange diamonds) on Texas Pelagics mostly from South Padre Island mostly, but also includes 1 trip from Port Aransas and 2 trips from Port O’Connor. Sighting coordinates are available for 27 trips most from SPI, and coordinated from the remaining 25 + Texas Pelagics are not available.

Cory’s Shearwaters are more evenly distributed over the middle to outer shelf and into deep pelagic waters then are Audubon’s Shearwaters.

View Shearwater Distribution in a larger map

Click on the box in the upper left of the map to view the map legend.

Click on each sighting symbol and the data label will appear showing the time, date and the number of birds seen.

Click on the link on the bottom of the map to view a larger map.


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