BOHA Waterbird Monitoring Update: June 29th 2012

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 12^th, 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!

-Carol

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BOHA Waterbird Monitoring Update: June 12, 2012

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 12^th.  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 31^st 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

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BOHA Waterbird Update: May 30 & 31, 2012

Busy week, last week!  On May 30^thwe 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 31^stwe 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

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