The state summer tourism ads are working—winter visitors stayed for the sun and the beach crowds, including a Brant at Westport from July 27–29 and single King Eiders in August at Eastham and Duxbury Beach. The only other August record this century for King Eider was from Rockport in 2009. Also unseasonal was a male Bufflehead present for the beginning of July at Wachusett Reservoir.
The annual August deepwater pelagic trip run by the Brookline Bird Club has been invaluable in showing us what lies and flies off our watery horizons. Sadly, this year's trip was cancelled due to bad weather. Who knows what was lurking out there? For those pelagic birders confined to terra firma, Provincetown has been the go-to place to scope passing shearwaters. This summer, though, birders didn't even need binoculars; unprecedented numbers of Great Shearwaters (up to 24,000) were seen in the surf and at the water's edge. The birds have been feeding on the billions of menhaden fry driven to the shore by mackerel and other predatory fish.
Equally significant was an unusual event to the south, in Buzzards Bay, where shearwaters are rarely encountered. Observers at Gooseberry Neck have been recording almost unprecedented numbers of Cory's Shearwater (see figure 1). On July 22, recorders tallied 1,397 birds flying east into the bay. The day before, 636 Cory's were accompanied by an extraordinary report of an Audubon's Shearwater. This diminutive shearwater is a warm-water bird, usually seen only on pelagics that venture beyond the continental shelf and into the warmer Gulf Stream. The large number of shearwaters (including a handful of Great, Manx and Sooty shearwaters) may indicate a sudden food bonanza similar to that at Provincetown, where a probable Audubon's was also sighted. Spencer Fullerton Baird (first curator of the Smithsonian Institute and perhaps more familiar to us as the eponym for a sparrow and a sandpiper) noted a similar phenomenon in the fall of 1886 when "thousands" of Cory's Shearwaters entered Buzzards Bay. Apparently, young sea herring, chased into the bay by predatory mackerel and bluefish, attracted the shearwaters that year.
Figure 1. Cory's Shearwater: monthly high counts for July (solid line) and August (dotted line) 2000–2017 in Buzzards Bay (area bounded by southern coasts of Bristol and Plymouth Counties, western Cape Cod, and the Elizabeth Islands). Data from eBird.