Thursday, 19 November 2015

Cape Verde shearwaters

Some years ago (I'm too polite to say exactly how many) a group of intrepid birding greats including the likes of Tony Marr, Dick Newell, Richard Porter and Robin Jolliffe undertook a series of pioneering trips to Dakar, Senegal. These very capable birders embarked on a series of pelagic trips and recorded thousands of the fabled Cape Verde shearwater (Calonectris edwardsii) in the waters off Senegal. Additional, impressive passage counts of more familiar species such as Sabine's gulls and Pomarine skuas were also recorded. Years later, the immense potential for superb sea watching off Senegal continues to steadily gather momentum. 

Over the past few years I have spent a number of occasions with Tony, sea watching at the Butt of Lewis. During our many birding conversations we often discussed the possibility of me finding the  elusive Cape Verde shearwater, whilst undertaking my numerous surveys off the West coast of Africa. Despite much time scrutinising sea birds off the likes of Morocco, Mauritania and further south Gabon and Ivory Coast I have never managed to find one of these birds. Over the last week I have been working off Senegal and have enjoyed watching Cory's shearwaters on a daily basis- a few birds may have been candidates for Scopoli's shearwater  and I have also seen two great shearwaters and a solitary Manx shearwater. A few days ago whilst studying the Cory's I noticed some 'large shears' that although superficially resembling Cory's, appeared a tad smaller and slimmer (by about 10%?). These birds appeared slightly stiffer-winged, and possibly had slightly faster wingbeats- I'm trying not to string anything here! With better views the birds appeared to have more chocolate brown tones to the head as opposed to the generally diffuse greys of the Cory's. These birds also have more brown on the underwing. In certain light conditions the birds appeared rather 'capped'- something the Cory's never showed. Upon closer scrutiny it was apparent that the birds had thinner, grey bills although this has proven difficult to utilise as a useful field characteristic except when the birds ventured very close in and under very good light conditions. Generally though, the lack of a typical Cory's massive, yellowish bill can be a useful indicator under the right circumstances and with birds that 'cooperate'! With increased practice I have managed to pick up a few birds at greater distances, based on the faster flight action and generally slimmer/darker jizz, although readily admit it is not easy! Having managed a few photographs I was delighted to see that they were indeed Cape Verde shearwaters- a seabird 'lifer' for me. 



Identification is fairly straightforward at these distances! 


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