Neil Haywardand Robert H. Stymeist
Gulls by Richard Johnson
Weather-wise, July and August are good months for conducting breeding bird surveys and watching the start of the fall shorebird migration. July saw average temperatures below normal and the month felt more like spring than summer; the average temperature in Boston was 72 degrees, two degrees below normal. The high for the month was 93 degrees on July 19, part of a three-day heat wave with temperatures in the nineties. The only other day that hit 90 degrees was July 2. A low pressure to our southwest in mid-July kept all of New England to a near record cool; the high in Boston on July 14 was just 67 degrees! Rainfall totaled 4.03 inches in Boston, a little more than normal. The most rain in any single day was 1.41 inches on July 24.
On August 1, an estimated 100,000 Tree Swallows were noted on Plum Island. Photograph by Bob Stymeist.
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WATERFOWL THROUGH SKIMMERS
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.
CUCKOOS THROUGH FINCHES
The fall migration of Common Nighthawk, beginning in the last weeks of August, is an event to which many birders look forward. However, reports of this enigmatic goatsucker in Massachusetts appear to be decreasing in recent years, consistent with a general population decline. A recent study from the American Bird Conservancy showed populations of Common Nighthawk and other aerial insectivores, including Chimney Swift, have dropped by more than 70 percent since the mid-1970s. Chuck-wills-widows were noted from Plymouth, Chappaquiddick, and Falmouth.
Early to mid-July is still a good time to get a pulse on breeding bird abundance. A South Shore Bird Club trip to Quabbin Reservoir (Gate 10) on July 1 tallied some impressive numbers: 11 Yellow-bellied Sapsuckers, 11 Eastern Wood Pewees, 78 Red-eyed Vireos, 26 Veeries, 54 Ovenbirds, 24 Chestnut-sided Warblers, and 16 Scarlet Tanagers. Another census in Wendell on July 15 recorded 126 Red-eyed Vireos, 53 Eastern Towhees and 20 Scarlet Tanagers. Purple Martins had a very successful nesting season. Colonies in Rehoboth fledged 442 young, Mashpee 180, and Plum Island 109. Blue Grosbeaks were confirmed nesting at the Frances Crane Wildlife Management Area in Falmouth, only the second documented nesting in Massachusetts. The first nesting was confirmed just last year at Cumberland Farms in Middleboro. The full report of the Falmouth nesting by Nathaniel Marchessault appears in the October 2017 issue of Bird Observer Volume 45, No 5, pp. 326–329.