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We got the 2013 season off to a great start this week with eager and able volunteer crews and very cooperative weather!

On Monday, May 13th, we conducted ground-based counts on Great Brewster and Gallops Islands.  (Thanks to DCR and Rob Lowell for permission and instructions for visiting Gallops which is currently closed to the public). 


Arthur learns Gallops Island is closed!
(Gallops, 5.13.2013, CLT)

On Great Brewster, we had a total of 83 Herring Gull (HERG) nests and 14 Great Black-backed Gull (GBBG) nests, as well as one American Oystercatcher (AMOY) presumed to be nesting on the landing beach and another territorial pair on the south end of the island.  We also flushed several Common Eider (COEI), though we did not comprehensively search for eider nests.  On Gallops Island, we had 35 GBBG nests, 4 HERG nests, 2 COEI nests and 2 AMOY nests with locations known.  New volunteers Carol and Alexis jumped right in… and got comfortable very quickly!  


Alexis gets comfortable while recording a Black-backed Gull nest.
(Gallops, 5.13.2013, CLT)

On Thursday, May 16th, we conducted a thorough ground-based count of Sarah Island.  We detected a total of 123 HERG nests and 21 GBBG nests throughout the island, along with 179 tree-nesting Double-crested Cormorants (DCCO).

Bob & Wayne hard at work. (Sarah Island, 05.16.2013, CLT)

Bob & Wayne hard at work.
(Sarah Island, 05.16.2013, CLT)


Wicked busy tree…
(Sarah Island, 5.16.2013, CLT)

Wading bird numbers were down significantly from the last count in 2009, though Great Egrets seem to be holding their ground.  


Flushed Great Egrets.
(Sarah Island, 5.16.2013, CLT)

Great Egret chick. (Sarah Island, 05.16.2013, CLT)

Great Egret chick.
(Sarah Island, 05.16.2013, CLT)

In total on Sarah we found 158 Black-crowned Night Herons (BCNH) nests, 86 Great Egret (GREG) nests, 10 Snowy Egret (SNEG) nests, and 2 Glossy Ibis (GLIB) nests.  We also found 5 pairs of nesting Canada Geese, 2 America Black Duck nests, and a Common Grackle nest in amongst the waders.  In addition, there was a pair of territorial AMOY on the south side of Sarah, though no nest was detected. 

Black-crowned Night Heron nest. (Sarah Island, 05.16.2013, CLT)

Black-crowned Night Heron nest.
(Sarah Island, 05.16.2013, CLT)

Our timing was great this year – most of the waders were on eggs with just a few nests of young GREGs and BCNHs.  This timing is ideal to maximize information about the full season’s nesting effort, but minimize the disturbance we create at the colony site.  We did notice a large number of Black-crowned Night Herons in the trees on Langlee Island that did not appear to be birds flushed from Sarah, but a quick landing on Langlee did not turn up any signs of nesting there.

Below is a draft comparison of numbers from these 3 sites from the State census counts in 1994-5 and 2005-6, as well as our wader numbers from Sarah in 2009.  Unfortunately, it doesn’t paint a very pretty picture at first glance…  This year, colonial nesting bird surveys are being conducted not only throughout the rest of Massachusetts, but also region-wide from Virginia to Maine.  It will be very interesting to see the results come in and find out if the trends we are seeing in Boston Harbor match what is happening in the rest of the region. 

 New Picture (1)

Next week we are planning to get to the wading bird colony on Sheep Island and hopefully learn what others are finding out about ‘our’ birds on Outer and Middle Brewster and Calf Islands, which are also being surveyed this year.  More soon – Happy Spring!

Black-crowned Night Heron chick. (Sarah Island, 05.16.2013, CLT)

Black-crowned Night Heron chick.
(Sarah Island, 05.16.2013, CLT)

Hi all!

We wrapped up the season last Thursday with boat-based surveys of Snake Island and the Outer Harbor.  We observed 7 adult American Oystercatchers with 4 chicks on Snake, as well as one adult on Fisherman’s Bend in Winthrop and one adult on the shore of the Logan runway.  Susannah reported 5 fledged chicks on Snake earlier in June.  Of the four we saw last Thursday, 3 were two young to have been observed in June, indicating that Snake has potentially produced at least 8 fledged chicks this season!

Searching for American Oystercatchers in the Outer Islands. (CLT, 7.26.2012)


Unfortunately, observations of oystercatcher productivity elsewhere in the Harbor have been less fruitful… We observed 2 adults on Calf, 1 adult on Little Calf, 1 adult on The Graves, and 1 adult on Shag Rocks, all feeding intertidally.  No other fledged chicks were observed.  A summary of oystercatcher observations throughout the 2012 season and our ‘best guesses’ for productivity outcomes are attached.

Harbor Seals and Common Eider on The Graves. (CLT, 7.26.2012).


Other items of note on Thursday were a Whimbrel on Green Island, and 6 harbor seals hauled out on The Graves.  We also noted feeding Spotted Sandpipers on Snake, Calf, Little Calf, Green, Middle Brewster, and Outer Brewster.

Harbor Seals hauled out in The Graves. (CLT, 7.26.2012).


Thanks you all for a wonderful season!

Hi everyone!
Things are definitely winding down for the season in Boston Harbor (at least bird-wise). On Thursday we spent the morning following up on American Oystercatcher pairs observed earlier in the season. We detected active pairs on Button and Sarah in Hingham Harbor, as well as a pair on Grape Island. Oddly, one of the adults on Button appeared to be incubating, which seems unlikely given the late date… We also detected 9 adult oystercatchers on Sheep Island and another 3 on Hangman.

Cormorant colony on Middle Brewster (CLT, 07.12.2012).

During a landing on Great Brewster we found only a single pair of oystercatchers on the south end of the island. There were two pairs nesting on the landing beach earlier in the season. In a trip around the Outer Islands we observed 3 adult oystercatchers in flight on the south end of Calf and another adult on the rocks off the east side of Calf. We also detected an adult (may have been the same previously seen in flight) on the west end of Middle Brewster. There were no pairs observed on Green or Outer Brewster where we had observed them earlier in the season. No oystercatcher chicks were observed.

Other items of note: Wading birds colonies were still quite active on Sarah and Sheep. We spotted a Harbor Seal off Hangman. And we observed many Spotted Sandpipers feeding on the rocks all over the place! We also noted a handful of young eider in the Outer Islands, but remaining chicks are now large enough to be extremely difficult to distinguish from adult females, so no formal survey was conducted.

Hope you are all having a great summer! Our last trip will be on July 26th, after which I’ll provide a more complete summary of American Oystercatcher observations for the season.


Yesterday’s effort ended in heavy rain at 8:20am, but we got in a solid hour+ of work before that came to pass…

It appears that the tern colony on Lovell’s has been abandoned for this season.  Rangers have reported a rat infestation and we saw ample rat tracks during our visit yesterday.  After being washed out by the early June moon tide it appears they’ve given for this year.  Good news is that, although two adults were hanging around, it looks like the Great Black-backed Gull pair that was nesting in the tern colony on Lovells also gave up for the season after being overwashed earlier in the month.  Adult and young Killdeer were still running all over the beach!


Searching for eiders off Green Island (CLT, 6.29.2012).

We began a boat-based survey for eider ducklings in the Outer Harbor and made it to The Graves before the rain came.  At that point we’d counted 113 females without ducklings and 11 females accompanying a total of 6 ducklings in 3 separate crèches.  For comparison, looking at a comparable portion of the survey from June 12th, we had 91 females without ducklings and 16 females with 10 ducklings.  Although I’d like to think there were a whole bunch of eider ducklings hiding out somewhere we didn’t get too, I tend to suspect this was a low productivity year for Common Eider in the Harbor Islands.  While in the Outer Islands Friday we also observed adult American Oystercatchers on Calf and Green Islands (we did not get to the Brewsters).

Hope everyone is enjoying a good start to summer and has a Happy Fourth of July!


Snake Island marsh (CLT, 6.12.2012).

Good morning everyone.  Sorry for the delay in getting this out… we had a productive, though somewhat disappointing, trip to the islands last Tuesday, June 12th.  Our goal was to conduct our official visit island tern nesting areas within the State survey window and to check up on active AMOY pairs and eider ducklings.

Common tern nesting platform, Spinnaker Island, Hull (CLT, 6.12.2012).


Common Terns on nesting platform off Spinnaker Island (CLT, 6.12.2012).

We started the day with a visit to Snake Island where we confirmed 5 pair of territorial American Oystercatchers and 3 pair of Willets.  There were no terns nesting on Snake this year.  We then proceeded to the tern nesting platform off of Spinnaker Island in Hull.  Unfortunately, it isn’t possible to access the platform directly, but upon flushing birds, we estimated adult 163 Common Terns attending the colony.  This number is about in the middle when compared to recent years (2011: 133 adults; 2010: ~260 adults; 2009: 130 adults; 2008: 250 adults).



Bob and Tim counting Common Eider off Green Island (CLT, 6.12.2012).

 A boat-based survey in the Outer Islands turned up a total of only 16 eider ducklings attended by 25 females.  We detected another 274 females with ducklings in the area.  For comparison, on May 31st we detected 214 eider ducklings accompanied by 153 females, so these numbers have shifted dramatically.  In general, we have had our high counts for the season occur in mid-June.  This season was definitely a little ahead of schedule, but nonetheless, anecdotally appears to have been a year of high duckling mortality which is not uncommon for this species.  During eider crèche surveys we observed 3 adult American Oystercatchers feeding on Green Island and 1 additional adult on Calf.


Looking for Common Eider ducklings in The Graves (CLT, 6.12.2012).


We ended the day with a stop at the tern nesting colony on Lovells Island.  It appeared that the site did overwash during high tides the previous weekend, but there were 5 adult terns in the area and we located 4 1-egg nests, indicating a likely renesting effort.  A number of empty scrapes were also present, so numbers could be growing.  The Killdeer nesting on Lovells appears to have been successful and several cotton-ball Killdeer chicks were running around.  The two Great Black-backed Gulls were still in the area, but it did appear that their nest was also overwashed in the June moon tide.


Tracks on the beach at Lovells (CLT, 6.12.2012).


This week’s trivia question:  Can you identify all the tracks appearing in the attached picture from the beach at Lovells?  Hint: there are 4 species represented…

Hope everyone’s week is off to a good start!  -Carol

Busy week, last week!  On May 30thwe had planned to visit Sarah Island to count nests in the wading bird colony located there, but a preliminary boat-based survey around the island indicated that we had already missed our opportunity for this season.

Boat-based survey of Sarah Island (CLT, 5.30.2012).

Many chicks were present in the colony, and some visible egret chicks were already quite large.  Visiting a colony when large chicks are present can cause tremendous disturbance with serious consequences.  If young are mobile enough to ‘branch’ when scared, you run the risk of young falling from the nest site.  Because herons and egrets are altricial and require parental care, any earlier-then-planned exit from the nest can result in abandonment and starvation… needless to say, this is not a scenario we want our survey efforts to produce.  Although we would have liked to have included Sarah with the other wading bird sites in the park this year, it will become a priority next May.  Boat-based observations did count 87 nesting Double-crested Cormorants on Sarah and ascertain that Great Egrets, Snowy Egrets, Black-crowned Night-Herons, and Glossy Ibis were all present and nesting there.


With a high tide in Hingham Harbor and no herons to survey, we decided to conduct a boat-based survey in search of American Oystercatcher pairs.  One pair of AMOY were detected on Button, as well as a pair on Bumpkin and one quiet adult that may have been one half of a pair on Slate.  Three pair of AMOY (1 with 2 chicks and 1 with 1 chick) were observed on Sheep Island, along with nesting GREGs, SNEGS, GLIBs, and BCNHs and 13 DCCOs. We also located a pair of AMOY and an extra adult on Hangman.  No American Oystercatchers were observed on Langlee, Ragged, Sarah, Grape, or any of the south facing beaches of Peddocks (including Prince’s Head).

We finished our day last Wednesday with a ground based survey of Rainsford Island where we observed 2 pair of territorial American Oystercatchers, one with 2 chicks.  We also observed 7 Spotted Sandpiper territories, but did not locate any nests.  No terns were active in the area. 

Friendly Mallard chasing the landing craft… (CLT, 5.30.2012).

However, while we were searching the island, Russ was befriended by a very social female Mallard.  She apparently became quite besotted with him (with no encouragement on his part) and hopped in and out of the landing craft trying to attract his attention.  Upon leaving the island she attempted to follow the boat, swimming along behind and taking short flights to keep up with us… A transplant from the public garden, perhaps?

Boat-based survey of the Outer Islands (CLT, 5.31.2012).

On Thursday, May 31stwe started the day with a boat-based survey in the Outer Islands where we counted 214 eider ducklings accompanied by 153 females.

Common Eider flotilla in the Roaring Bulls (CLT, 5.31.2012).


Generally, our highest counts of the season occur in mid-June, so this number may still be rising though everything has generally been a little ahead of schedule this spring…  We also observed 3 pairs of American Oystercatchers on Calf Island and 1adult from the pair nesting on Middle Brewster.  We did not see the pair previously nesting on the landing beach on Outer Brewster. 

Graves Light (CLT, 5.31.2012).


A ground-based survey of Great Brewster resulted in 2 pair of territorial American Oystercatchers and one Common Eider nest.  

Middle and Outer Brewster, from Great Brewster (CLT, 5.31.2012).

We ended the day with a visit to Lovells where 8 adult Least Terns were observed actively defending the colony site.  

Bob S. observing Least Terns on Lovells (CLT, 5.31.2012).

Unfortunately, we also observed a Great Black-backed gull nest with 2 eggs in the same area.  One pair of American Oystercatchers were observed loafing in the intertidal are on the west side of the island and 4 Spotted Sandpipers were noted feeding intertidally on the east side.  We were also confronted by an adult Killdeer doing her absolute best to convince us that she (with 2 broken wings!) was an easy target

Killdeer doing ‘broken wing’ display, Lovells Island (CLT, 5.31.2012).

and that we shouldn’t waste our time continuing on the path from the beach to the center island that just happened to have her nest, with four perfect eggs, planted right in the middle of it!

Perfect Killdeer nest on Lovells (CLT, 5.31.2012).


Till next week!  -Carol

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!