Archive for May, 2012

Hi everyone,

On May 17thwe did a ground-based survey on Outer Brewster looking for Common Eider and wading birds.  We conducted a thorough search of all but the very eastern tip of the island and found 42 Common Eider nests (average of 4.41 eggs).  We estimated approximately 135 adult Black-crowned Night-Herons, 27 Snowy Egrets, 7 Glossy Ibis, and 1 Great Egret in residence in the center island colony.  Upon closer inspection we were able to access and count 41 BCNH nests, 21 SNEG nests, and 3 GLIB nests.  Snowy Egrets appear to be significantly more abundant then when last counted (12 nests) in 2009.  Black-crowned Night-Heron nests were also more abundant then previous counts (36 in 2009).  A pair of American Oystercatchers was also observed nesting on the landing beach and a nest with 2 eggs was located.  Although (as you all know!) we focus our efforts EXCLUSIVELY on waterbirds, we also collectively (read – Bob & Wayne) managed to spot a variety of migratory species moving through the island, including Parula, Black-throated Blue Warbler, Magnolia Warbler, American Redstart, Common Yellowthroat, Black-and-White Warbler, Black-capped Chickadee (!), Veery, Savannah Sparrow, Ruby-throated Hummingbird, and an unidentified Empidonax flycatcher.

Snowy Egret nest in Outer Brewster colony (CLT, 5.17.2012).


On May 18th we conducted our first boat-based survey in the Outer Islands.  We confirmed what we think was a third pair of AMOY on the east side of Calf Island (2 nest sites were found on the 14th) along with pairs on the landing beaches on Middle and Outer Brewster and spotted a pair on the seawall on Great Brewster.  Cormorant and gull numbers appeared similar to previous years (see attached) and will be verified with comparisons to digital photos taken during the survey.  We also observed 5 immature Great Cormorants on the Graves and 3 immature Great Cormorants on Outer Brewster; no sign of nesting adults…yet!    Following our boat-based circuit, we landed on Middle Brewster where we detected 43 eider nests during a through search of the entire island.  For comparison, 28 nests were found there in 2009.  No BCNHs were observed on Middle Brewster, though we have found small numbers nesting there in the past.

Waterbird Monitoring volunteer Pat Dolan searching for eider nesting on Middle Brewster (CLT, 5.18.2012).



Nesting Double-crested Cormorants on Middle Brewster (CLT, 5.18.2012).

Hoping to avoid the rain and make it too Sarah in the morning!



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Yesterday (May 14th) was the official launch of the 2012 Boston Harbor Waterbird Monitoring Season!  

Polly & Wayne searching for eider nests on Calf Island. (CLT, 5.14.2012)


Common Eider nest on Calf Island. (CLT, 5.14.2012).

We had great conditions and started the field season with a ground-based nest count of Common Eider on Calf Island.  We were met at the island by a group of federal and state biologists interested in obtaining blood samples from the Boston Harbor nesting colony to further their investigations of ‘Wellfleet Bay Virus’, the newly described virus that is thought to be responsible for recent large scale eider die-offs on Cape Cod.  (Check out this recent Cape Cod Times Article on Wellfleet Bay Virus:http://www.capecodonline.com/apps/pbcs.dll/article?AID=/20120310/NEWS/203100335).



Avian Disease Coordinator, Sam Gibbs, & State Waterfowl Biologist, H. Heusmann band and obtain blood sample from a nesting Common Eider in Boston Harbor. (CLT, 5.14.212)


While the visiting researchers worked on the north end of the island, we counted nests on the southern end of Calf.  We found a total of 26 nests, which is a bit higher than the 18 nests found on that portion of the island when last surveyed in 2008.  Notably missing were the Black-crowned Night-Herons previously known to be nesting in the lilacs and willows in the center of the island – there were 13 BCNH nests and 30 adults in 2008, and only a few adults and no nests on this visit.  We also located two American Oystercatcher nests – one with 2 eggs and one chick!


American Oystercatcher nest on Calf Island (CLT, 5.14.2012).


If you have an interest in eider research, you may enjoy these beautiful photos from a project going on in my neck of the woods…. Common Eider Research in Rhode Island: http://coastalbirds2.blogspot.com/2010/01/wintering-ecology-of-common-eider-in.html

Back out in the island on Thursday…stay tuned.


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