There is increasing evidence of a die-off of Great Shearwaters Puffinus gravis along the Atlantic coast of the Bahamas. The shearwater die-off is a phenomenon that happens every five to ten years. In the Bahamas it last occurred in 2007.
According to the late Dave Lee these are young Great Shearwaters migrating from their natal home in the South Atlantic to their feeding grounds off the US and Canada. The combination of poor food supply and wind conditions in the doldrums that make the passage unusually strenuous leads to the birds expending all their energy and expiring. It is a normal event for this species and has been recorded many times.
Great Shearwater
Information taken from Seabirds.Net.
References:
Lee, D.S. 2009. Mass die-offs of Greater Shearwater in the Western North Atlantic: Effects of weather patterns on mortality of a trans-equatorial migrant. Chat 73: 37-47.
Watson, G. 1970. A shearwater mortality on the Atlantic coast. Atlantic Naturalist 25: 75-80.
John Cooper, ACAP Information Officer, 01 July 2015