BOHA Waterbird Monitoring: May 13 & 16, 2013

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 13^th, 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 16^th, 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)

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)

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)

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. 

 

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)

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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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BOHA Waterbird Monitoring Update, July 2011

Alas, another season is behind us…  We finished up our 2011 efforts with two trips on July 19^th and 26^th

Boat-based Surveys (CLT, 7/19/2011).

 

On the 19^th, we began our day with a boat-based survey in the Outer Islands.  We counted a total of 519 female Common Eider and 97 ‘distinguishable ducklings’.  (It was recently pointed out to me that ‘ducklings’, as opposed to ‘chicks’, is the preferred nomenclature for referencing juvenile eider.  I have further qualified it with ‘distinguishable’ since, by this point in the season, some ducklings are undoubtedly large enough to escape our notice and get counted as adult females.)  Anyway… in addition to 97 distinguishable ducklings, we also detected 2 adult American Oystercatchers with 1 fledged juvenile on Calf Island and another group of 2 adults and 1 fledged juvenile on Outer Brewster.  Foraging Spotted Sandpipers were noted on Green, Outer Brewster, Shag Rocks, and Little Brewster and 1 harbor seal was spotted on the Graves.   After a season counting eider ducks in Boston Harbor, some of you may be interested to know that this species has a long history of human interaction and sustainable eiderdown harvest still takes place in Canada, Iceland, and other areas of the Artic today.  The Norwegian Island of Vega was recognized as a UNESCO World Heritage Site in 2004 and has since been added to my dream travel list (see http://whc.unesco.org/en/list/1143).

Fishing the Graves (CLT, 7/19/2011).

 

The Least Tern colony on Lovells Island has dispersed after what appeared to be a successful season.  The Great Black-backed Gull that nested just outside the colony still lingers in the area with one fat and healthy chick.  A carcass found nearby may have been the second chick, who was not in evidence during our visit.  One Spotted Sandpiper, acting quite territorial, was also noted nearby on Lovells. 

In addition on the 19^th, we also observed two adult American Oystercatchers with 1 fledged juvenile on Peggy’s Point on Gallops Island, but did not see any on Rainsford during a boat-based survey.  Eight Wilson’s Storm-petrels were working the water between Lovells and George’s and Spotted Sandpipers were foraging on both Gallops and Rainsford, presumably having completed their nesting efforts for the season.

Snake Island (CLT, 7/26/2011).

On the 26^th, we took advantage of the morning high tide and landed on Snake Island where we observed 10 adult American Oystercatchers and 5 fledged juveniles along with 34(!) Willets.  There were 7 adult Common Terns in the area.  We came upon one abandoned tern nest with 2 eggs and then, quite surprisingly, found 2 very young Common Tern chicks on the beach.  Although we saw terns in the area during our initial visit in late May, the end of July is quite late for nesting terns.  Black-crowned Night-herons, a Great Blue Heron, a Great Egret, Least Terns, Short-billed Dowichers, Greater Yellowlegs, Lesser Yellowlegs, Semipalmated Plovers, Semipalmated Sandpipers, Song Sparrows, Red-winged Blackbirds, and European Starlings were all foraging on Snake – more evidence that the breeding season is over and fall is shortly upon us.

 

Boston Skyline form Snake Island (CLT, 7/26/2011).

During a boat-based survey of the Outer Islands on the 26th we counted 426 female Common Eider and just 21 ‘distinguishable ducklings’.  Ducklings born in May or early June should be approaching full size and are quite capable of traveling across open water to feeding sites along the mainland.  It is not at all surprising that so few young ducklings were present and very much appears to have been a successful season for eider overall.  Adult American Oystercatchers were detected on Little Calf, Calf, Green, Outer Brewster, and Shag Rocks (with a fledged juvenile?).  One Great Cormorant and 1 gray seal were observed on the Graves and a single Spotted Sandpiper on Middle Brewster.

We ended our day with a landing on Sheep Island where we spotted 9 American Oystercatchers, at least one of which was a fledged juvenile.  One adult had a yellow leg band, one letter of which was ‘K”.  An adult with code YE(CK) was banded on Sheep in 2009 and re-sighted in 2010, so it may have been the same individual again.  Also on Sheep were nesting Herring and Black-baked Gulls, Double-crested Cormorants, Glossy Ibis, Black-crowned Night Herons, Snowy Egrets, and Great Egrets.  We noted at least 7 Spotted Sandpipers, along with Least Sandpipers, Ruddy Turnstones, Semipalmated Sandpipers, and Semipalmated Plovers all foraging in the intertidal.

 

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BOHA Waterbird Monitoring Update: June 28, 2011

Tuesday was exactly the kind of day for which we wish!  Sunny and calm, not too hot…. Perfect!

Least Tern chick on Lovells Island (CLT, 6.28.2011).

 

The Least Tern colony on Lovells Island continues to be very active with approximately 80-85 adults attending.  We began a second complete nest count, but quickly chose to abandon the effort since many young chicks were present and we did not wish to cause unnecessary disturbance during such a critical phase of the breeding season.  The Great Black-backed Gull earlier reported to be nesting on Lovells was carefully brooding two chicks just outside the tern colony.  This is the first record I know of a nesting gull on Lovells – as Marc said earlier, ‘Nice to live close to where you eat.’  We’ll see…

Great Black-backed Gull Brood on Lovells Island (CLT, 6.28.2011).

 

A boat-based survey of the Outer Islands turned up 159 Common Eider chicks associated with 86 females.  An additional 357 females were in the area.  Compared to previous years, these numbers suggest only moderate success this season.  We also kept watch for any dead adult eiders on island beaches, but saw done.  In addition to eider chicks, we also observed a pair of territorial American Oystercatchers on Outer Brewster, and another pair with one fledged chick on Middle Brewster!  We spotted at least 3 gray seals around The Graves, several Wilson’s Storm-petrel east of the Brewsters, Spotted Sandpipers on Middle and Outer Brewster, and one immature Great Cormorant on Shag Rocks.

Common Eider females tending chicks (CLT, Green Island, 6.28.2011).

 A boat-based survey of the west side of Great Brewster resulted in one pair of territorial American Oystercatchers.  No accompanying chicks were spotted, but the fact that the adults are still on territory is encouraging.  There were also approximately 47 additional female Common Eiders in the area. 

 We finished the day with a complete boat-based survey of Rainsford Island.  No American Oystercatchers were observed, but lots of Spotted Sandpiper activity was noted and 9 additional female Common Eiders were in the area.   Back out on July 6^th!  Happy Fourth of July!

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BOHA Waterbird Monitoring, 6/20/2011

Our last trip before the Summer Solstice occurred on Monday, June 20^th.  The weather was lovely with Our last trip before the Summer Solstice occurred on Monday, June 20^th.  The weather was lovely with very light winds, so we took advantage of the opportunity to conduct a boat-based survey for Common Eider chicks around the Outer Islands. We ended up with a total of 199 chicks on our regular Outer Islands circuit – and then saw five more feeding off the rocks on Lovells a bit later in the morning. 

Common Eider with chicks off Shag Rocks (CLT, 6.20.2011).

This was our first real eider crèche survey this year and numbers seem reasonable given previous years data.  For comparison, in 2010 we counted 341 chicks on 6/16 (!) and had counts of over 250 throughout the season, but in 2009 we reached our high count of 196 in early June and plummeted from there.  It will be interesting to see what we turn up next week.

 

Double-crested Cormorant nesting colony (Middle Brewster, CLT 6.20.2011).

We also observed an incubating American Oystercatcher on the landing beach on Outer Brewster and an active pair on the landing beach on Middle Brewster.  No other AMOY were observed, so the fate of those we saw on Calf, Little Calf, and Green are unknown.  Though we did not see any Great Cormorants, nesting Double-crested Cormorants remain very active feeding young.  We also observed a couple of Wilson’s Storm-petrels in the area, and at least 2 harbor seals and 4 gray seals around the Graves.   

Hauled out Harbor and Gray Seal (The Graves, CLT 6.20.2011).

 

The Least Tern colony on Lovells remains active.  We did not conduct a complete count, since we had been there only 5 days earlier, but we did check in on adult numbers and they seemed stable.

Least Tern nest on outskirts of Lovells Colony (CLT, 6.20.2011).

 

Thanks to Marc and crew for posting signage in the area. 

Lovells Island Least Tern Colony (CLT, 6.20.2011).

Killdeer chicks we had previously noted on the beach last week also seemed to be coming along fine (does anything look more ridiculous that a baby Killdeer?) 

Killdeer chick (Lovells Island, CLT 6.20.2011).

 

Susannah and Pat also observed a pair of territorial American Oystercatchers on the north side of Lovells.  Although we did not find chicks, their behavior strongly indicated they had unfledged young nearby – a first for Lovells!

 

Hard-working Volunteers!

Enjoy these long days – maybe we’ll even see the sun sometime?!?

-Carol

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BOHA Waterbird Monitoring, 6/16/2011

After another bout of awful weather, we were finally able to get back to the islands on Wednesday, June 16^th.  

Least Tern Colony, Lovells Island (CLT 6.16.2011)

Our reward was 75 Least Tern nests on Lovells!  (See above – not bad real estate, huh?)  There was also a pair of Killdeer with 4 chicks on the beach nearby.  

Nesting Least Terns and Killdeer (Lovells Island, CLT, 6.16.2011)

After leaving Lovells, we headed to the tern nesting platform off Spinnaker Island, near Hull.  At first it appeared there was little activity,

No Common Terns this year? (Spinnaker Tern Platform, CLT, 6.16.2011)

but once Russ brought the boat all the way in to the piling, VIOLA!  We estimated that (approximately) 133 adult Common Terns flushed from the platform.

Common Tern Nesting Platform (Spinnaker Island, CLT, 6.16.2011)

A cruise by the beaches surrounding Prince’s Head on Peddocks turned up no American Oystercatchers this year.  However, we did count 29 nesting or brooding Great Black-backed Gulls on Hangman, along with one nesting Double-crested Cormorant – a first for me!  There was also a pair of territorial American Oystercatchers spotted on Hangman, though no chicks were observed.  We attempted a trip to the Outer Islands, but were rebuffed by rough seas.

Hopefully, we’ll have better conditions for eider chick counting when we head out tomorrow!  Also of note, you may remember that we sighted a Herring Gull with a green wing tag on Great Brewster a couple of weeks ago – the following information about that bird was provided to me by Ken Mackenzie from DCR:

 Here is some specific information on K99:Captured 2/4/11 at South Bay Center, South Boston, MA; Capture location (GPS): 42.3297805, – 71.063811; Captured using a rocket net baited with crackers and bread; Adult male herring gull; Green wing-tags: K99; Red leg band: 55; Federal leg band: 1146-31807; Released on site:  Sightings:  This is the first sighting of this gull since its capture in February.  Thank you!

 Ken would love reports of other tagged gulls, so please keep your eyes open!

 

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BOHA Waterbird Monitoring Update, 6/4/2011

After a slow start to the season, we’ve had two weeks of glorious weather and finished up May with a lot to show for our efforts!

The Graves, 5.25.11 CLT.

We kicked off the season for real on Wednesday, May 25^th with a boat-based survey of the Outer Islands.  Have you ever visited the Graves on a day like this?!?  Incubating gull and cormorant numbers appear generally similar to previous years (see boat_counts_boha11.pdf, attached) – special thanks to Bob K. for observing and Pat for testing out electronic data collection with CyberTracker!  Upon reaching the Outer Islands, we were greeted by three pair of American Oystercatchers just south of Calf Island.  Based on observations during the rest of our loop, we believe that at least one pair is nesting on Calf and one pair on Middle Brewster.  The third pair may have come over from Great Brewster (see 5/26 report) or there may be a second pair on Calf.  We also spotted single adult AMOYs on intertidal rocks on Little Calf and Green Islands.  There were still lots of adult male and immature male Common Eider ‘hanging around’ and 42 eider chicks were observed in small groups around the Graves, Middle, and Outer Brewster.   (Although we missed our window to assess nesting eider this year, we will be tracking chick numbers beginning in mid-June.)  Other items of note were 2 Harbor Seals on the rocks near Green Island, a juvenile Great Cormorant also on Green, and an adult GRCO on intertidal rocks off Outer Brewster – a future nesting waterbird species perhaps?  On our way back to the dock on the 25^th, we checked out the beach on Lovells where a few Least Terns were circling, but no nesting activity was noted.  We also observed 2 AMOY feeding off Lovells and counted 14 nesting Herring Gulls and 15 nesting Great Black-backed Gulls on Gallops.

American Oystercatcher nest with two chicks on Great Brewster Island (5.26.11, CLT).

We headed back out on the 26^th, taking advantage of the high tide and starting our morning with a visit to Snake Island in Winthrop where we observed 5 pair of American Oystercatchers and 5 pair of territorial Willets.  In an effort to minimize disturbance, we did not search heavily for nests but territorial behavior was definitely apparent.  Two Least Terns and 2 Common Terns were spotted in the area, but there was no indication of nesting.  Also of note were Black-bellied Plover, White-winged Scoter, Killdeer, Ruddy Turnstones, Northern Rough-winged Swallows, and a Saltmarsh Sparrow (a species I had previously seen on Snake… though apparently Bob S. didn’t really believe me until he saw it for himself!)  A visit to Great Brewster yielded 2 additional AMOY pairs who both nested on the landing beach where one pair has been found in previous years.  The first nest held one egg and two brand new chicks being earnestly defended by their parents from interested gulls at the ready nearby.  (My advice to nesting oystercatchers is – DON’T BUILD YOUR NEST NEAR A GULL COLONY – they never seem to listen to me….) Combined gull counts on Great Brewster resulted in 108 Herring Gull nests and 9 Great Black-backed Gull nests, most of which held 3 eggs.  We also observed a Herring Gull with a green wing tag numbered 99, which appears to be a bird tagged as part of a DCR water supply study (see http://www.mass.gov/dcr/watersupply/watershed/study/index.htmfor more on this).  A loop around Spectacle on our way back in yielded a whole lot of nothing, but it does not look like mowing has taken place yet, so that is great news for nesting birds.

Carl & Susan nest searching on Great Brewster (5.26.11, CLT).

This past week we spent Tuesday, May 31^st conducting boat-based surveys in the Dorchester and Hingham areas.  It appears to be a busy year for American Oystercatchers with a single adult spotted on Slate, 1 pair on Bumpkin, 1 pair on Sarah, 1 pair (with 2 chicks!) on Button, and 2 pairs with a possible 3^rdon Sheep.  Gull and Cormorant numbers were similar to previous years:  Sarah (101 HERG, 11 GBBG, 85 DCCO), Ragged (1 HERG), Button (8 HERG, 2 GBBG), and Sheep (123 HERG, 4 GBBG, 15 DCCO).  Cormorant numbers on both Sarah and Sheep are up from previous years and Herring Gulls seem to be down, but I haven’t yet had the chance to run through all the numbers.  Also, although not our primary focus this year, wading bird colonies on Sarah and Sheep were quite active with all the expected species present.  Finally, a landing on Rainsford turned up 2 MORE pairs of AMOY, 2 nesting GBBG, 1 nesting HERG, and approximately 11 territorial Spotted Sandpipers – an extremely consistent figure, though we had little luck with nest searching in 2010. 

Sheep Island (5.31.11, CLT).

So for those of you keeping score at home, it appears we have at least 17 or 18 pairs of American Oystercatchers on territory in the islands, and we haven’t yet visited Thompson or Peddocks.  So, we are on track for consistently high numbers again in 2011!   We’ll be back out counting again the week of June 13th…  See you then!

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BOHA Waterbird Update, 7/22/2010

We had a productive, though breezy, morning on July 22^nd with lots of good news to share from the islands!

The Least Tern colony on Lovells is quite active with numerous chicks present.  We decided not to enter the colony site since chicks were running around everywhere (!) but observed at least 26 adult terns present.  Several adults appeared to still be incubating nests, but most were feeding and tending young (see attached pics).    We also observed 5 Common Terns on Lovells, including one fully fledged juvenile still begging its parent for a handout (teenagers are all the same regardless of species).  Although we know these Common Terns did not breed on Lovells they were quite territorial – maybe they are prospecting new sites for next season?

We were prevented from visiting Snake due to a surprise LNG delivery, but did visit the Hingham Harbor Islands after receiving a report of an American Oystercatcher pair with chicks on Sarah Island.  We saw no sign of AMOY on Sarah, but did see one pair flying around the area between Ragged and Button.  We did not observe any chicks present, but sometimes they are pretty sneaky.

We landed on Sheep Island where we found 3 pair of AMOY.  One pair had a fledged chick and one of the adults from this pair was banded there in 2009 (yellow band – ‘CK’).  The other two pairs were very active and territorial, but we did not observe chicks or nests.  In addition to AMOY, Sheep also has very active gull and wading bird colonies; young Glossy Ibis were readily visible.

A visit to Hangman turned up little except gull chicks, though there were a number of eider and one White-winged Scoter in the area.  We finished the morning with a quick pass by Rainsford.  The AMOY pair that had been incubating on the tern nesting beach was not present there, but we did find a pair on the rocks by the landing beach.  No chicks appeared to be present with them, but we’ll take a closer look next week.

(See Bob Stymeist’s excellent photos from the trip at http://www.flickr.com/photos/rstymeist/4818840410/)

-Carol

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BOHA Waterbird Update, 5/18 & 5/24, 2010

The 2010 season is off to a great start with beautiful weather for our first two trips on May 18^th and May 24^th.  (Who has visited The Graves on a day like this !?!)  On both days we took advantage of calm seas and conducted boat-based counts of double-crested cormorants and gulls in the Outer Islands.  Overall numbers of DCCO, GBBG, and HERG appear very similar to previous years (see summary attached), however we did see some significant shifts in spatial distribution.  There appear to be slight declines in several colonies and a significant increase on Middle Brewster, where the cormorant colony has spread under sumac adjacent to the nesting cliffs.

Middle Brewster 2009 (no DCCOs)

Middle Brewster 2010 (new DCCO nests under sumac).

We also noted a marked increase in the presence of Great Cormorants in the Outer Islands, with 6 adults and 5 immatures detected on 5/18, and 4 adults and 3 immatures detected on 5/24.   Great Cormorants (http://www.allaboutbirds.org/guide/Great_Cormorant/id) are a more northern species that winter in Boston Harbor, but nest further north with a few sites in Maine and Canada.   In colony sites in Maine, Bald Eagles are thought to be a significant source of cormorant predation, though the worldwide populations of this species are secure.

Some Recent Press on Great Cormorants (thanks Bob!):

http://www.workingwaterfront.com/articles/Great-cormorants-threatened-in-Midcoast-Maine/13072/

http://www.pressherald.com/archive/eagles-rebound-but-now-a-threat-to-other-birds_2009-05-15.html

During boat-based surveys, we also detected a total of 3 pair of American Oystercatchers during each survey in their predictable locations on Calf, Middle Brewster, and (possibly) Outer Brewster.  Male Common Eiders were still present in the area and several groups of females with chicks were observed.  We had a total count of 20 chicks on 5/18 and an astounding 226 chicks on 5/24!   Our all time top count of eider chicks on the water was 279 chicks on May 30, 2008, so it appears the eider are off to a great start this year and possibly a bit ahead of schedule.  We will continue to monitor common eider crèches during the month of June.

During a landing on Lovells Island on 5/18, 5 feeding American Oystercatchers were detected, but no evidence of nesting was observed.  No terns, spotted sandpipers, eider, or rabbits (!) were seen.  A landing on Georges Island on 5/24 resulted in a similar dearth of waterbirds, but was a great opportunity to learn more about the island from ranger and waterbird volunteer, Andy Leahy.

Other items of note during our first week were peregrine falcon sightings on both days and a Red-necked Phalarope on 5/24.

Looking forward to a busy season & hoping for more great weather! -Carol

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