Cory's Shearwater
Calonectris diomedea borealis


Photographer

Dick Newell

Date

19th October 01

Location

Dakar, Senegal

Previous Picture Sooty Shearwater

Up To UpSenegal October 2001

Cory's Shearwater Next Picture


The first 2 pictures here are of the same bird.

Although Dakar is directly on the route between the Mediterranean and South Africa, the normal wintering grounds of diomedea, any kind of larger Calonectris is very scarce in October. We found field identification difficult. Here one can see a long, but slender bill, a smaller head and slimmer neck than typical borealis and a contrasting pale mantle and hind neck. All of these points are subtle, subjective and none are diagnostic.

I asked Ricard Gutiérrez to comment and he replied:

"[These birds] are borealis from the Canaries, as the birds in which I based my paper [in Dutch Birding] were largely from [the] Azores in the extreme west side of the cline of this species connecting both forms, the Atlantic (borealis) and the Mediterranean (diomedea). Hence, the Canary islands birds are a bit more graceful than those from the Azores and a bit closer to diomedea but still longer billed and structurally different.
The amount of black in the underwing does relate to its [geographic] position. More studies on the amount of black and grey in both webs of outer primaries are needed but I feel the existing criteria are good."


P00743

P00744

P00745

Previous Picture Sooty Shearwater

Up To UpSenegal October 2001

Cory's Shearwater Next Picture

Home Home | Search Search

If you wish to comment, feel free to send a mail message by clicking this icon Send email

© 2001 Magik Circle Limited http://www.magikcircle.com