Probable Trindade Petrel off Cape Verde Islands

Mike Greenfelder, a naturalist with Lindblad Expeditions, sent these three video grab images taken last month near Brava (Decimal coordinates 14.8507°, -24.705°) in the Sotavento (southern island group) of the Cape Verdes.

The bird appears to be an intermediate-morph Trindade Petrel, Pterodroma arminjoniana. However, as Mike points out, Atlantic Petrel Pterodroma incerta is quite similar in overall patterning but shows less extensive white on the 'hand' of the underwing. Typically this is limited to a silvery sheen on the bases of the primaries. Furthermore, the bill does not strike me as chunky enough, nor the head rounded enough for Atlantic. Trindade Petrel nests in Brazilian waters and ranges regularly into Gulf Stream waters off east coast of the United States. In addition, there are at least two records from the Azores (18th July 1997 and 17th May 2006).

Here are the pertinent comments from his email: "On Sept. 30 [2008] we were in Zodiacs 0.5 miles south of the southern tip of Brava Island in the Cape Verde group. We were watching Melon-headed whales in flat seas when a very interesting petrel flew around us. I didn't have a camera but our video guy shot video of it. I made a few stills, which I have attached. To me it looked like an Atlantic Petrel, but with white underwings. Trinidade Petrel is the best I have come up with, but there doesn't seem to be anything similar in range, so obviously an interesting sighting. Looks similar to Herald Petrel drawings, but I have heard that Atlantic may show some white in underwing with wear."

Seawatch - Long Island, New York USA

Once the rains had cleared this afternoon (30 August 2008), I toured some of the coastal spots between The Springs (Town of East Hampton) and Montauk Point (Google Coordinates 41.071900, -71.859000), Suffolk Co., Long Island. For this first time this summer terns were much in evidence, mostly COMMON and ROSEATE TERNS with fledged birds of the year, but an influx of BLACK TERNS Chlidonias niger surinamensis were the stars. After noting a Black Tern in Gardiner's Bay off Fireplace Beach, I found greater numbers in Napeague Bay (18) and on the Atlantic Ocean off Hither Hills (>50) and around Montauk Point (45). Smaller groups of terns, including more Black Terns, were found at several other spots. Shoals of Bluefish and Stripped Bass were actively feeding off Hither Hills and Montauk, the ocean seeming to boil in places because of the mass of predatory fish that were gorging on tiny bait fish (1-2 cm). This tiny prey was also being picked off by the terns hovering over the surface. At Montauk Point, some of the surf casters were hooking strippers and bluefish on every cast but I was pleased to see that most of fish went straight back in the water unscathed.

On the ocean off the Hither Hills camp ground (41.010241, -72.007429), 5 PARASITIC JAEGERS were harassing a large congregation of Laughing Gulls and terns. When the piscine activity subsided, the jaegers pulled out within minutes of each other, flying eastwards relatively close to shore. I tentatively aged them as two 1st summers, 2 second/third summers and 1 molting adult. They kept going towards Ditch Plains and vanished into the sea mist. Very nice!

However, the 'bird of the day' for me was a large LEATHERBACK TURTLE Dermochelys coriacea that surfaced 100 yards off the beach at an overlook at the western end of Montauk village. The view point is high enough that through a scope, I could see the ridges and barnacles on the marine turtle's back as well as its long black flippers and immense eyes. Loggerheads are not uncommon offshore in summer but it is a treat to see one from land.

BLACK TERN - 118 (sum of high counts from various spots)
Forster's Tern - 5, Napeague, Montauk and Montauk Pt.
Common Tern - 1,550
Roseate Tern - 190++
Laughing Gull - 300
Northern Gannet - 1, Hither Hills
PARASITIC JAEGER - 5, Hither Hills then moved east.
Common Loon - 3, Hither Hills at edge of feeding frenzy

Some other birds of note were:
Northern Harrier - 2, female-types, Hick's Island
Turkey - 9, Amagansett and Napeague
Solitary Sandpiper - 1, Deep Hollow Ranch Pond
Lesser Yellowlegs - 4, Rita's Stable Pond
Spotted Sandpiper - 4, Montauk area
Semipalmated Sandpiper - 2 Deep Hollow and Rita's
Black-bellied Plover - 20 incl. 1 at Deep Hollow (south side Rt 27)
Western Willet - 1, Napeague Harbor
Eastern Willet - 2, Napeague Harbor (late! noticeably shorter legged and darker than accompanying Western)
American Oystercatcher - 2, Napeague
Bobolink - 1 male, Promised Land Fish hatchery
Ruby-throated Hummingbird - 3, Montauk Point below restaurant

Humpbacks and seabird bonanza in the Great South Channel

Earlier this week, I joined the annual CRESLI whale watching adventure to the Great South Channel, a gouge in the seabed that separates Cape Cod and the Nantucket Shoals from the western edge of George's Bank. This north-south passage is used by several species of whales in the spring and fall as they transiting between the hyper-productive waters of the Gulf of Maine and warmer but less bountiful waters of the mid-Atlantic and Gulf Stream.

Organized by Dr. Artie Kopelman, this 51-hour trip aboard the 140 foot (42.7 meter) Viking Starship departs from Montauk, NY and is designed to intercept female Humpback Whales Megaptera novaeangliae and calves of various ages as they feed intensively on herring and other small fish in anticipation of their southward migration to the tropics. This has to be one of the best opportunities to see, hear and dare I say it, smell, Humpbacks in the North Atlantic! One of Artie's most frequent calls over the PA system was, "we are officially surrounded by whales", his glee barely concealed. The unflagging enthusiasm of the CRESLI participants is equally impressive. Each and every whale encounter is greeted with the same unfettered excitement as the first - a rare thing in these jaded, 'I've seen it all', times.

For our entire stay in the GSC, it was almost impossible to look around and not see a breaching animal or puff of blow. Even at night, the insomniacs were busily whalewatching by deck light as a group of inquisitive animals loafed alongside the Viking Starship, spinning lazy somersaults a few feet from the rail throughout the early hours. This amazing show continued well after dawn, with the youngsters rearing up out of the water to get a look at the peanut gallery of 'oohing and 'ahhing' spectators leaning over the rail, pocket cameras and coffee cups in hand. Although rich in plankton, the green water was still clear enough for us to see the white underparts and enormous flippers of the gyrating animals below us and we marveled at their ability to 'turn on a dime', breaking the surface with a squeaky puff on one side of the boat and then the other.

Researchers from the Whale Center of New England were aboard, including Jennifer Tackaberry who manages the North Atlantic Humpback Whale catalog. Some 28 different individuals were photographed and Jen, who knows her catalog inside out, recognized 18 previously named individuals. At least three mother/calf pairs were studied at length to document the pairings, providing information about breeding success, reproductive rates and so on. The fact that at least 10 of the photographed whales were unfamiliar is particularly exciting, evidence perhaps of an influx from elsewhere. Further scrutiny of the images and databases may shed more light on this. We probably saw more whales than this but just did not have time to sit alongside each and get usable images of the raised tail flukes to allow unambiguous identification.

Early in the trip we encountered a good-sized Fin Whale Balaenoptera physalus, a handful of Short-beaked Common Dolphins Delphinus delphis and on the second day, a highly cooperative pod of 30 or so Pilot Whales Globicephala sp. that swam alongside for a while, allowing their curious calves to peek at the boat. Eventually, the pod grew tired of us and simply vanished into the depths. With water temperatures in the mid-50's, I would predict these to be Long-finned Pilot Whales Globicephala melas, however, the lack of a prominent pale patch behind the dorsal fin on the adult male and larger females raises the possibility of Short-finned Pilot Whale G. macrorhynchus. There seems to have been an incursion of warm water onto the Continental shelf this summer, evidenced by better than usual numbers of Cory's Shearwaters Calonectris diomedea in New England and New York, and so Short-finned might not be such an outlandish possibility.

Although the trip is focused on collecting population data on the Humpback Whales as part of on-going CRESLI and WCNE research projects, it provides great opportunity to study and photograph a variety of seabirds. The numbers of Great Shearwater Puffinus gravis, Wilson's Storm-Petrel Oceanites oceanicus and Common Tern Sterna hirundo were truly impressive. In fact, the throngs of commoner species were overwhelming at times and with only four sets of eyes scrutinizing the birds rather than fixed on the whales, lots of good stuff was probably missed in the happy chaos. Highlights were a South Polar Skua Catharacta maccormicki that passed right over the bow, good numbers of Pomarine and Parasitic Jaegers Stercorarius pomarinus and S. parasiticus and at least fifteen Leach's Storm-Petrels Oceanodroma leucorhoa. Landbird migration is getting underway and we were visited by several sandpipers, three warblers and a Purple Martin Progne subis. It would be great to have more seabird enthusiasts join us in future years to help pick through the abundant birdlife. My daily bird counts are as follows:

DAY 1 (11 Aug 2008)
Emerged from the banks of mist filling Nantucket Sound shortly after dawn and spent the entire day over the GSC, surrounded by whales.

Cory's Shearwater - 35
Great Shearwater - 5,119
Sooty Shearwater - 65
Manx Shearwater - 5
Wilson Storm-Petrel - 1,240
LEACH'S STORM-PETREL - 6
Northern Gannet - 6
Semipalmated Sandpiper - 3 (briefly inspected boat before moving on)
Red-necked Phalarope - 1
large shorebird sp. - 10+
Herring Gull - 5
Great Black-backed Gull - 45
Black-legged Kittiwake - 1
Common Tern - 1,450
SOUTH POLAR SKUA - 1
Pomarine Jaeger - 12 (incl 3 ads)
Parasitic Jaeger - 2
Northern Waterthrush - 1 (Nicknamed "Lucky" the bird flew around the ship many times before gaining the courage to land. Fed and watered by some kind-hearted participants, and narrowly missing being stood on several times. Remained for most of next day until jumping ship when Nantucket and mainland in sight).
Prairie Warbler - 1 (spent a few hours inside the main cabin before disappearing)

DAY 2 (12 Aug 2008)

With whales from pre-dawn to 10 am when we began the 12.5 h steam back to Martha's Vineyard (4:00 pm) and Montauk (10:30 pm).

Common Loon - 9 (Nantucket Sound)
Cory's Shearwater - 39
Great Shearwater - 2,159
Sooty Shearwater - 19
Manx Shearwater - 1
Wilson Storm-Petrel - 357
LEACH'S STORM-PETREL - 9 (several close to vessel)
Northern Gannet - 5
Herring Gull - 18
Great Black-backed Gull - 67
Laughing Gull - 30 (Nantucket Sound and Martha's Vineyard Sound)
Black-legged Kittiwake - 1 (harassed by Parasitic Jaeger)
Common Tern - 980
Black Tern - 1
Pomarine Jaeger - 3 (including 1 adult with large tail spoons)
Parasitic Jaeger - 4
Northern Waterthrush - 1 (from previous day)
American Redstart - 1
Purple Martin - 1

My thanks to Dr. Artie Kopelman and his intrepid band of CRESLI volunteers for putting together another fantastic trip.

Ireland's mystery shearwater revealed

For a few nights each summer since 2004, an unfamiliar seabird has been heard calling from the rocky slopes of Skellig Michael, a dramatic islet off the coast of Ireland's County Kerry (Google Coordinates 51.7689°, -10.5423°). This June the calls were recorded by a visiting film crew headed by Eamon de Buitlear and identified by Killian Mullarney and Magnus Robb (authors of Petrels Night and Day: A Sound Approach Guide) as a male Cory's Shearwater (Calonectris diomedea).

Armed with a tape, Alyn Walsh and Mullarney revisited the site where they successfully caught and ringed the shearwater. The closest known breeding site for Cory’s Shearwater is on the Berlengas Islands, a small archipelago off central Portugal (39.4151°, -9.51258°) some 850 miles south of Skellig Michael. Interestingly, a few pairs of Scopoli's Shearwater nest on the French coast near Bordeaux (Mays, Durand and Gomez 2006 Ornithos 13: 316), a mere 650 miles away.

A UNESCO World Heritage Site, Skellig Michael (Great and Little Skellig) host large colonies of Manx Shearwater Puffinus puffinus, European (British) Storm-Petrel Hydrobates pelagicus, Northern Gannet Morus bassanus, alcids and Red-billed Chough Pyrrhocorax pyrrhocorax.

Will the Skellig Cory's Shearwater return next summer? Will he succeed in luring a mate? Could there be other Cory's or Scopoli's Shearwaters visiting North Atlantic seabird colonies?

See Irish Birding and Birdwatch Magazine for the full story.

Petrels Night and Day: A Sound Approach

Ever wondered what White-faced Storm-Petrels sound like? No, they don't go "boing, boing, boing" as their wave hopping antics would suggest. A spectacular new book by Magnus Robb, Killian Mullarney and others called Petrels Night and Day: A Sound Approach Guide, has the answer and much, much more.

Using two CD's worth of sound recordings, a wonderfully readable text, eighteen full-page color plates and a heep of spectacular photographs, the authors take us on a sweeping tour through the eastern North Atlantic and Mediterranean in search of petrels, shearwaters, fulmar and storm-petrels. The result is a master work that sets a new standard for natural history guides. The material on field identification is absolutely cutting edge, with detailed treatments of several potential new splits. Pelagic birders on both sides of the Atlantic will find this a treasure trove of information and an inspiration.

Checkout the Oceanwanderers Bookshelf for the full review.

In albatrosses, two moms can be better than one.

A recent paper by Lindsay Young (University of Hawaii) and colleagues reveals an interesting example of cooperative behavior and prompts the question of how often this occurs in seabirds where males and females show little difference in appearance.

Here is the abstract:

Unrelated same-sex individuals pairing together and cooperating to raise offspring over many years is a rare occurrence in the animal kingdom. Cooperative breeding, in which animals help raise offspring that are not their own, is often attributed to kin selection when individuals are related, or altruism when individuals are unrelated. Here we document long-term pairing of unrelated female Laysan albatross (Phoebastria immutabilis) and show how cooperation may have arisen as a result of a skewed sex ratio in this species. Thirty-one per cent of Laysan albatross pairs on Oahu were female–female, and the overall sex ratio was 59% females as a result of female-biased immigration. Female–female pairs fledged fewer offspring than male–female pairs, but this was a better alternative than not breeding. In most female–female pairs that raised a chick in more than 1 year, at least one offspring was genetically related to each female, indicating that both females had opportunities to reproduce. These results demonstrate how changes in the sex ratio of a population can shift the social structure and cause cooperative behaviour to arise in a monogamous species, and they also underscore the importance of genetically sexing monomorphic species.

Citation:
Young LC, Zaun BJ, Vanderwerf EA. Successful same-sex pairing in Laysan albatross.
Biol Lett. 2008 Aug 23;4(4):323-5

Socotra Archipelago named World Heritage Site

The Socotra Archipelago (12.489158°, 53.907147°) is made up of four small and arid islands and two rocky islets that jut out from the Horn of Africa into the northwest Indian Ocean. In July 2008, Socotra was officially designated a UNESCO World Heritage Site in recognition of its distinct flora and fauna. Some 37% of Socotra’s 825 plant species, 90% of its reptile species and 95% of its land snail species are endemic. The islands also supports globally significant populations of land and sea birds, including a number of threatened species. The marine life in the waters around Socotra is also very diverse, with 253 species of reef-building corals, 730 species of coastal fish and 300 species of crab, lobster and shrimp. Politically, the islands belong to the Republic of Yemen but not surprisingly, are also claimed by Somalia which is geographically closer.

There seems to be mixed information about the namesake Socotra Cormorant (Phalacrocorax nigrogularis). Birdlife International 2003 reports that this Near-Threatened regional endemic occurs in small numbers as a non-breeding visitor throughout the archipelago and is more widespread elsewhere in the Arabian Gulf, Arabian Sea and Gulf of Aden. However, Dave Sargent's January 2006 exemplary trip report indicates the cormorants breed and can be very numerous in places.

Other nesting seabirds include Jouanin's Petrel Bulweria fallax Persian Shearwater Puffinus (lherminieri) persicus, Red-billed Tropicbird Phaethon aethereus, Masked Booby Sula dactylatra, Brown Booby Sula leucogaster, White-eyed Gull Larus leucopthalmus, Sooty Gull Larus hemprichii, Great Crested Tern Sterna bergii, Lesser Crested Tern Sterna bengalensis, Sooty Tern Sterna fuscata, Saunders' Tern Sterna saundersi, and Brown Noddy Anous stolidus.

Non-breeding visitors include Wedge-tailed Shearwater Puffinus pacificus, Flesh-footed Shearwater Puffinus carneipes, and Wilson's Storm-Petrel Oceanites oceanicus.