Friday, 26 July 2013

Gulf Stream Seabirding

19 July 2013

Cape Hatteras, North Carolina

I was keen to make the most of a short spell of garden leave before I start a new job at the beginning of August, ideally somewhere I could clear my head and see a few good birds. I really fancied a pelagic and started investigating Madeira and Lanzarote. However having done both before and knowing July isn't the best time for either I started to consider further afield. Cape Hatteras in North Carolina has a long established reputation for excellent pelagic trips run by Brian Patteson out into the Gulf Stream that runs north about 30 miles offshore. The local delicacy here is Black-capped Petrel and they also have a history of pulling in some exciting rares, so you never quite know what you might encounter.

It just so happened that Brian was running a three day summer special over 19 to 21 July. Perfect! I booked up for all three days and arranged flights. I flew out on 18th and drove south from Norfolk via a town called Suffolk (weird) and along the coastal peninsula to Cape Hatteras at the end of the Outer Banks. Next morning I was up at 05:00 and drove the five minutes to the Hatteras Landing Harbour where 'Stormy Petrel 2' was moored. 

Stormy Petrel II - taken on our return
The pelagic was fully booked on Friday and I joined the other 20 or so hopefuls on the quayside to await our 05:30 departure.  We were soon welcomed on board by Kate Sutherland and Brian Patteson and given an overview and safety brief before we set sail. A Common Loon (Great-northern Diver) in the estuary was a surprise on the way out. We motored at speed (c20 knots) for about 2 hours SE over the shelf edge and into the blue waters of the Gulf Stream, some 30 miles offshore. The change in water colour was quite incredible from a deep green inshore to a beautiful clear blue in the current. The current was running at 5-6 knots and the sea surface temperature was some 82F. It is this flow of warm tropical water that brings birds north, often associated with floating Sargassum seaweed. While there was some small pieces of weed it was not present in the hoped for quantity, as many of the rarer species, such as Tropicbirds are associated with it.

Kate laid the chum: two holed bottles of fish oil dangling either side of the stern to create the slick and a wire cage on the end of a rope filled with frozen minced fish, which left small morsels of tasty food floating behind as it melted. Occasionally the slick would be enhanced with small pieces of Shark liver that Kate carefully sliced up at the back of the boat.  Unlike other pelagics I have done Brian runs the chum permanently as he zigzags around the current waters pulling in birds and occasionally stopping and back doubling to see what has been attracted in. 

It was fairly calm on Friday, very sunny, hot and humid. Visibility was very good throughout the day and there was little swell, but just enough wind for the birds to move around.

We encountered good numbers of flying fish on the way out some very close to the boat, but surprisingly few birds. However as soon as the chum was deployed Wilson's Petrels appeared and we had a good flock continuously all day.
Wilson's Petrels

Wilson's Petrel - this southern ocean breeder spends the summer in some numbers in the Gulf Stream

The yellow webs between its toes are just visible here
Very long legs, which it uses to bounce over the water looking for food
The water is kicked up as it bounces along
Wilson's Petrel 
Close views as they come in to the back of the boat
As I scanned the growing flock a Band-rumped Storm-Petrel appeared and joined the throng. These larger, longer winged Storm Petrels are easily picked as the glide and shear  on slightly bowed wings. The first one caused some excitement as a number of the other birders were new to pelagics. About 30 were encountered over the day with upto five on the slick at any time. As usual there were some moulting birds, and some clean birds, some larger and browner, some smaller and blacker. Howell distinguishes these as Grant's and presumed Madeiran respectively, though with at least four species level taxa in the North Atlantic this is open to some speculation.

Typical bowed wing approach of a Band-rumped (Grant's) Storm-Petrel
A very moulty bird, large and presumably a Grant's
A nice clean plumaged, darker and slighter bird - presumably a Madeiran
Band-rumped Storm-Petrel
Not quite so comfortable with the boat as Wilson's they would shear back down the slick
Band-rumped Storm-Petrel
Band-rumped Storm Petrel
Band-rumped Storm-Petrel
The number of shearwaters was surprisingly low. Only 13 Cory's and 2 Greats were seen and none came onto the chum, often whizzing past or briefly taking an interest. We did encounter six Audobon's Shearwater, of which I saw five, but none very well as they whizzed past the boat. 

Cory's Shearwater
Cory's Shearwater 
Great Shearwater
The hoped for Black-capped Petrels did not disappoint with over 30 birds seen during the day. They would often approach from a great distance, presumably having picked up the scent of the chum and followed the slick gradually to the boat. Occasionally they would stick around often encouraged with a little shark liver. Most were in fairly heavy wing moult. Dark faced birds outnumbered white-faced quite considerably.

Black-capped Petrel (dark-faced)
Black-capped Petrel (Dark-faced)

Black-capped Petrel (white-faced)
Black-capped Petrel (white-faced)
Black-capped Petrel (white-faced)
Black-capped Petrel (white-faced)
Black-capped Petrel (dark-faced) 
Black-capped Petrel (dark-faced)
Black-capped Petrel (dark-faced)
Black-capped Petrel (dark-faced)
Black-capped Petrel (white-faced) with a Wilson's Petrel. Note the face pattern and reduced chest spur
Black-capped Petrel
Black-capped Petrel
As hoped a couple of bonus birds appeared during the day, though neither stayed with us for very long. The first was a 1st summer Bridled Tern that flew into the chum from the starboard side had a look around and then flew off to port. These are fairly frequent visitors to the Hatteras pelagics, particularly after any storms to the south and when the Sargassum weed is plentiful.

First-summer Bridled Tern

First-summer Bridled Tern
First-summer Bridled Tern
A first-summer Pomarine Skua flew in later in the afternoon, drifted along the port side and immediately away into the open ocean.

Pomarine Skua
However the real day's highlight came mid afternoon. George Armistead spotted a distant blow from a Whale. It was quickly identified as a Sperm Whale that appeared to be logging on the surface. With some impressive boat driving we were soon getting close. We expected the whale to sound as we approached, but it didn't. Carefully we literally pulled right alongside the massive animal which just stuck its nose out to look at us and carried on enjoying the sunshine on its back! Absolutely amazing encounter.

The blow from the SPerm Whale was visible from some distance
The Whale's nose protrudes from the water - was it watching us?
The front half of the Whale as it drifts quietly away - we left it still logging!

The final encounter of the day came as we headed back to the shelf. A massive Loggerhead Turtle, easily the biggest I have ever seen, was spotted laying on the surface. I was on the bow spit with Kyle and we had sensational views as it took a breath, saw us and sounded just a metre below us.

Loggerhead Turtle

The totals for the day were recorded as:

Black-capped Petrel - 33
Cory's Shearwater - 13
Great Shearwater - 2
Audubon's Shearwater - 6
Wilson's Storm-Petrel - 130
Leach's Storm-Petrel - 1
Band-rumped Storm-Petrel - 28-31*
Bridled Tern - 1
Pomarine Jaeger - 1

Sperm Whale - 1
Loggerhead Turtle - 1

We arrived back in to harbour at 17:15. It was very hot and humid, but with several hours of light I decided to have a look around to see what local birds I could find.

As we came back into the bay passing numerous sand shoals and small low lying islands we encountered lots of breeding terns, gulls and herons. There were significant colonies of Royal Tern, Black Skimmer and Least Tern with a good flock of Brown Pelicans and loads of Laughing Gulls. 7 White Ibis flew over us on the way out, and Common and Sandwich (Cabot's) Tern were also encountered. 

Once on land I drove the short distance to Cape Hatteras Lighthouse. Roadside birding produced ten Cardinals, 2 Killdeer, 1 Red-winged Blackbird, 3 Northern Mockingbird, 3 Common Grackle, 3 Carolina Wren, 5 Black Duck, 1 Osprey, 2 Brown-headed Cowbird and 6 Mourning Dove. Purple Martin were common around the village as were introduced European Starling and House Sparrow.

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