When exploring the big blue—pelagic waters well beyond the reach of land-based seabird observers—one should always expect the unexpected. Of course there’s always no shortage of vast stretches of open ocean where birds are extremely scarce to nonexistent, save for the occasional Leach’s or Wilson’s Storm-Petrel. That’s life on the big blue. One may summarize this patchiness as interminable hours of intense boredom punctuated by fleeting seconds of unbridled excitement. However, it is the chance of encountering something unforeseen that eliminates any ennui brought on by the lack of seabirds or other marine life. Despite first impressions of the ocean being an aquatic desert, it in fact consists of a variety of habitats and associated organisms, constrained by the physical and chemical properties of sea water, particularly sea surface temperature and salinity, all further modified by the affects of wind and ocean currents.
The first week of Leg 2 of AMAPPS 2011 aboard the Henry B. Bigelow was no exception to the patchiness paradigm. Looking over what we saw, an impressive 19 species totalling 392 individuals, it’s obvious that we surveyed a wide range of habitats during the past six days, from subtropical to temperate; continental shelf to abyssal deep. Tropical and subtropical seabirds stole the show during our all-too-infrequent visits to southern and warmer offshore waters. Two White-faced Storm-Petrels (Pelagodroma marina), likely feeding on their favorite food, planktonic crustaceans and small fish, were seen loosely associating with Striped Dolphins. Even at a distance, as were these two, this small attractive seabird is easily identified by its peculiar manner of foraging and feeding: dancing and bouncing over the sea surface on exceptionally long legs, wings held open in a shallow “V” and executing erratic changes of direction while pushing off from the water with both feet like a tightly wound spring. These were the first (perhaps the last?) White-faced Storm-Petrels for the Henry B. Bigelow unless we return to the warmer waters of the Gulf Stream. This highly pelagic storm-petrel nests on remote islands in the south Atlantic such as Tristan de Cunha, as well as on Macaronesian islands off western Africa, including the Canaries and the Cape Verde Islands, the latter perhaps the source of the birds spotted by sharp-eyed observer Mike Sylvia. White-faced Storm-Petrel is a very rare summer visitor to warmer waters of the west Atlantic. Other noteworthy species seen during the two days we were in warm 25-26°C water were a couple of dark morph Trindade Petrels, two Black-capped Petrels, a single Bridled Tern, and several White-tailed Tropicbirds. Representing Greenland and the high Arctic were several Dovekies seen about 260 kilometres east of Nantucket, most likely birds who did not, for whatever reason, return north to breed, electing instead to remain on their wintering grounds.
In terms of overall abundance, Wilson’s Storm-Petrel again came out on top with 140 recorded in the 300 m strip transect. The following three most abundant species were all shearwaters and, interestingly enough, their totals were remarkably similar: Cory’s Shearwater (56), Audubon’s Shearwater (54) and Great Shearwater (53). A bird familiar to all, Rock Pigeon, was unexpected far offshore, perhaps a lost racing bird? If so, then there is a strong possibility it finished last. Other species of note included our first Royal Terns and a single South Polar Skua.
Michael Force, Mike Sylvia and Jeff Gleason, seabird observers