Thursday May 28, 2015 by Seabird McKeon

What is at the base of complex pelagic ecosystems?  Abiotic factors such as currents and solar energy certainly play a large role, but how about living organisms?  In most places pelagic marine ‘plants’ are exclusively planktonic.  Largely single celled, but hugely abundant, ecosystems rise and fall on the fate of the phytoplankton.  The gulf stream ecosystem is unique in that we have truly pelagic multicellular ‘plants’ supporting the rest of the crew.  Two species of Sargassum, S. natans and S. fluitans, tumble along the surface of the ocean, processing sunglight and collecting nutrients.  Often growing into clumps the size of a beachball, and sometimes pushed together into football field sized rafts, Sargassum has the size and density to lend small creatures in open water what they seek most: shelter.

Floating debris will quickly attract an entourage of small fish in blue water.  Pelagic sargassum also has this effect, with the added benefit of an entire community of organisms that only live with floating sargassum.  Today aboard the Stormy Petrel II, we had an opportunity to investigate the sargassum ecosystem from the bottom up.

Taking apart a sargassum mat on the back of a moving boat is an imprecise affair, but today we had a great haul.   Both S. fluitans and S. natans were present, along with all of the hydroids, bryozoans, and other encrusting fauna.  Two species of shrimp, the gleaners of this community, were abundant.  A single small pipefish wound it’s way around the ‘stalks’ of sargassum.  Small predators like the Sargassum Swimming Crabs were numerous.  The real find belonged to Kate, who discovered a young Sargassumfish in the weed (photo by Steve Howell). 

This small species of anglerfish is perfectly camoflauged as it creeps about the matt looking for any prey smaller than itself.

The dependents of sargassum were also numerous today, with numerous species of flyingfish captured on camera.  Flying fishes deposit their eggs on floating debris, including pelagic sargassum.  Ranging in size from a potato chip to larger than a storm-petrel, the fishes were easily seen in and above the glassy water, including the rarely photographed Midnightwing (by Steve Howell).

Of the birds seen today, several were notable for their association with pelagic sargassum.  The first of the day was a White-tailed Tropicbird, which briefly visited the boat, stunned all aboard, and departed.  Brian and Kate frequently assess the probability of seeing this species by the density of the sargassum and depth of the water - the White-taileds are usually around when there is ‘scattered grass’ in the deep.

Audubon’s shearwaters are another species frequently associated with pelagic sargassum.  It is not currently known if these little shearwaters feed on species of fish that require, or prefer the weed, or if the mats just attract an appropriate size of fish for the birds.  The overlap in the breeding range of the Audubon’s shearwater, and the portion of the tropical Atlantic that hosts pelagic sargassum year-round, provides a convincing backdrop for potential interaction. Several Audubon’s were seen throughout the day, with one sitting with a pair of Great Shearwaters long enough for photographs.

The last of the ‘sargassum birds’ was only the second individual for Spring Blitz this year.  The first sighting of Bridled Tern was as it hunted the edges of a dense patch of Sargassum, and searched for preferred perches among the floating debris.

Thanks to Brian, Kate, Bob, and Steve for another successful Spring Blitz trip!

Black-capped Petrel  26
Cory's Shearwater  47 (three Scopoli's Shearwater - nominate Cory's)
Great Shearwater  33
Sooty Shearwater  6
Manx Shearwater  1
Audubon's Shearwater  21
Wilson's Storm-Petrel  90-95
Leach's Storm-Petrel  12
Band-rumped Storm-Petrel  1
White-tailed Tropicbird  1
Bridled Tern  1
Arctic Tern  2
Sterna sp  3
South Polar Skua  1
skua sp  2
Parasitic Jaeger  1
Long-tailed Jaeger  6

Offshore Bottlenose Dolphin  about 40

Black-capped Petrel (Bob Fogg)

White faced Black-capped (Steve Howell)

Scopoli's Shearwater - two photos (Steve Howell)

Audubon's Shearwater (Bob Fogg)

Wilson's (R) & Leach's (L) Storm-Petrels (Steve Howell)

Leach's Storm-Petrel 1st cycle - note worn juvenile wings with abraded outer primaries (Steve Howell)

And 2nd cycle - note abraded tail & inner primaries (contrasting with fresher secondaries) (Steve Howell)

White-tailed Tropicbird!  (Bob Fogg)

This bird was a 2nd cycle individual (Steve Howell)

Bridled Tern (Bob Fogg)

Arctic Tern (Bob Fogg)

Parasitic Jaeger, adult individual (Steve Howell)

Offshore Bottlenose Dolphin (Steve Howell)

Atlantic Patchwing (Steve Howell)

Wednesday May 27, 2015 by Seabird McKeon

Every day in the Gulf Stream is a learning opportunity.  Today, the cards fell in a way that allowed us to make comparisons between different species found in this extreme environment.  Dropping speed from the run out, our first comparisons were between an adult Long-tailed Jaeger and the Arctic Tern it was harassing.   The larger size of the Jaeger was apparent as the two tussled.  A second jaeger then joined the mix, approximately the same size, but altogether different in coloration and pattern with a pale head, and mottled barring.   This first summer Long-tailed jaeger accompanied/annoyed the adult for several minutes, allowing all onboard to recognize the similarities and differences between the two birds. 

Our next chance for comparison between two similar birds came as a Great Shearwater feeding in the slick was joined by a Black-capped Petrel.  Though similar in coloration, with both birds sharing a black cap among other traits, the two birds could not have been more different in flight style.  The easy grace of the Black-capped in flight was in direct contrast to the sturdy, somewhat hurried flight of the Great Shearwater as it rushed about gathering food from the slick.

By mid-day, all eyes had turned to the growing flock of Wilson’s Storm Petrels behind the boat in anticipation of finding the two expected larger storm petrels:  Leach's, and Band-rumped.  Steve and Kate were quick to point out that the best way to find ‘something different’ is to know the common species very well.   All aboard were tasked with learning the toe-extension, wing shape, pattering behavior, and flight style of the Wilson’s, and most were up to the challenge when the first large storm petrel appeared.   Which one was it?  Did it have the light, bounding flight of the Leach's?  Or the ‘tiny shearwater’ look of the Band-rumped?  Was the tail square or forked?  How bright were the carpal bars?  Everyone worked hard at storm petrel identification, and both species were seen by all.

Heading in from a solid day of gulf stream birding, the wind picked up inshore, giving us our final comparison challenge- shearwaters at a distance.  All day we had been seeing Great, Sooty, and Cory’s shearwaters feeding around the boat.  Now they were maximizing the breeze to travel, and cut arcing turns as they raced across the field of view.   The towering of Sooty Shearwater, the ‘slacker’ style of Cory’s, the contour hugging Great Shearwater- each bird provided us with behavioral clues that allowed identification from afar.  

With as many as 10 ‘lifers’ for some participants, and great opportunities for up close comparisons of seabirds that most of us are lucky to see from a distance, today’s trip was an educational bull’s eye, and another Spring Blitz success story.  

Thanks again to Steve Howell, Bob Fogg, Sea McKeon, and Nate Swick for helping us lead the trip today!  Sea, thanks for writing the report, & Bob, Steve - thanks for the photos!  Thanks also to everyone who joined us for a day in the Gulf Stream!  -Kate

Black-capped Petrel  20

Cory's Shearwater  33

Great Shearwater  15

Sooty Shearwater  35

Audubon's Shearwater  11

Wilson's Storm-Petrel  120-140

Leach's Storm-Petrel  5-7

Band-rumped Storm-Petrel  2

Oceanodroma sp  2

Arctic Tern  2

skua sp  3

Pomarine Jaeger  2

Long-tailed Jaeger  8

jaeger sp  2

Bottlenose Dolphin  1

Spotted Dolphin  2

Black-capped Petrel (Bob Fogg)

White faced Black-capped (Steve Howell)

Leach's Storm-Petrel (Bob Fogg)

& by Steve Howell - note difference in bill when compared with Band-rumped, below

Band-rumped Storm-Petrel (non molting, possible Madeiran) by Bob Fogg

& by Steve Howell with Wilson's on the far left

Arctic Tern (Steve Howell)

Second cycle Pomarine Jaeger (Bob Fogg)

Long-tailed Jaeger, adult (Steve Howell)

& by Bob Fogg

 Two Long-taileds, adult & first summer (Bob Fogg)

First summer Long-tailed (Steve Howell)

 Near the beach there were five or six Long-taileds flying by!  Bob snapped this photo!

& some flyingfish by Steve Howell - Atlantic Patchwings

 Sargassum Midget

Tuesday May 26, 2015 by Seabird McKeon

The Stormy Petrel II had another fantastic adventure on 26 May, 2015. Departing the docks at a sharp 5:30, Cpt. Brian Patteson made his way around the tail end of Hatteras Island and headed for open water. Conditions were clear but a little rough, which made for slow going. We were joined by a group of young Atlantic Spotted Dolphins, who were playing in the waves that we found challenging. Dropping from running speed at about 8:30, the first bird for most aboard was a South Polar skua! The bird flew steadily out of sight, allowing for brief, but clear views. It was quickly replaced by a white-faced Black Capped Petrel sitting on the water, which allowed for a close approach before taking flight. This pattern, of small numbers of a diverse selection of birds, would hold throughout the day.
Wilson’s storm petrels slowly gathered in the fish oil slick that Kate purposefully dripped from the stern. They were joined by four species of shearwater - the lacksidasical flight of Cory’s contrasting with the more purposeful Sooty and Great shearwaters, and the manic little Audubon’s shearwater that would pass by all day at high speed. The erratic, bounding flight of Leach’s storm petrel separated it easily from the smaller Wilson’s storm petrel, when one of the participants noticed a whale blow.
“Sperm Whale!” was the shout from Brian’s wheelhouse as the lopsided spout puffed to one side. The whale spent nearly 10 minutes at the surface with us before raising it’s squared off flukes into the sky and sounding. We were above a marine canyon- deep water that would harbor the squid that these whales feed upon. They weren’t the only squid hunters in the area, and several Pilot whales were seen nearby, with Common Terns above. Some of the dorsal fins didn’t seem quite right though, and Steve Howell was the first to put the pieces together as he ID’d the species: “Rough-toothed Dolphin.” Tight groups of these odd looking, rare dolphins, slowly showed the field marks: a distinctive angular dorsal fin, a ‘reptilian’ head shape without a break between the ‘beak’ and the ‘melon’, white/pink lips, and a dark ‘cape’ marking along the back. Seen rarely in these waters, even Brian and Kate have only seen this species a handful of times. A little later in the day, offshore Bottlenose dolphins would allow for comparison, rounding out an amazing day of cetacean sightings.
The roll-out of species would continue, with shearwaters, petrels, and storm petrels all visiting the slick as we traveled north with the Gulfstream. Bob Fogg and I were discussing Tropicbirds on the bow, when one appeared as if by invitation. The White-tailed tropicbird dropped from above amidships, and proceeded to circle the Stormy Petrel II for more than 5 minutes, allowing everyone onboard great views of this sought-after species. Re-energized by the tropicbird encounter, the whole boat settled into finding Band-Rumped Storm Petrels, with Nate Swick leading the search among the Wilson’s and distinguishing Band-Rumps from Leaches. This activity was interrupted only by a challenging young jaeger, identified with photos as a Parasitic.

Working our way back inshore, we stopped to watch three Arctic Terns working a minor windline of Sargassum, their crisp wingbeats and long-tails distinctive over the blue water. Several adult Pomerine jaegers finished the day, spoon shaped tail feathers visible even from a distance. Coming back into the sound, everyone onboard was happy with another productive Spring Blitz trip to the Gulf Stream.
Thanks again to Brian, Kate, and the expert spotters Steve Howell, Bob Fogg, and Nate Swick for getting everyone on good birds safely. 

Black-capped Petrel  10
Cory's Shearwater  17
Great Shearwater  9
Sooty Shearwater  13-15
Audubon's Shearwater  22
Wilson's Storm-Petrel  170-200
Leach's Storm-Petrel  7-8
Band-rumped Storm-Petrel  4
White-tailed Tropicbird  1
Common Tern  1
Arctic Tern  3
Sterna sp  2
South Polar Skua  1
Pomarine Jaeger  3
Parasitic Jaeger  1
Long-tailed Jaeger  1
jaeger sp  2

Pilot Whale (prob Short-finned)  12+
Spotted Dolphin  5
Rough-toothed Dolphin  7
Bottlenose Dolphin (offshore)  2
Sperm Whale  1

Black-capped Petrels (Steve Howell)

Great Shearwater 2nd Cycle (Steve Howell)

Juvie Sooty Shearwater, Wilson's Storm-Petrel, and Great Shearwater in the background!  (Steve Howell)

Band-rumped Storm-Petrel on the water (Bob Fogg)

White-tailed Tropicbird (Bob Fogg)

 White-tailed Tropicbird (Steve Howell)

Pilot Whale (Steve Howell)

Rough-toothed Dolphin (Steno bredanensis) by Bob Fogg, second photo by Steve Howell

Sperm Whale (Steve Howell)

& fluke by Bob Fogg!

Monday May 25, 2015 by Brian Patteson

After five excellent days since we embarked on the 2015 spring blitz, I figured we were due for a duller day. Kate assured me that would not be the case. After all we had pretty blue water and light southeasterly wind. Sure enough we were greeted with Sooty Shearwaters in Hatteras Inlet. Soon thereafter a South Polar Skua crossed our wake a just a few miles out. Next a couple of Long-tailed Jaegers flew over the bow. Out at the shelf break there was not much activity, but a charter boat reported some shearwaters just a couple of miles offshore so we slowed down and started looking. We jogged out past 100 fathoms with no chum, and when we got to 150 fathoms, Kate alerted me about a small petrel headed our way in the sun glare. I slowed the boat and it sailed right in- BERMUDA PETREL! It was only 8:25. Ten minutes later were were still watching it! Black-capped Petrel was our second gadfly petrel of the day. As we worked out to deeper water, we added Leach's and Band-rumped Storm-Petrels to the day's list. Out on the horizon, I spotted a few tubenoses circling. We jogged out there and took a look. To our amazement we found a Bermuda Petrel among shearwaters and Black-caps. It looked identical to the first bird seen an hour before, and it was in no hurry to leave the area. By mid morning there wasn't much flying, so we scanned the water hard for flocks. Bob Fogg spotted a flock of four birds in the distance. As we approached, it looked like four Black- caps, but when they flushed (not close) a Fea's/Zino's Petrel revealed itself. It sailed off to the horizon. All the time we were looking we were dragging a flock of storm-petrels and shearwaters with our chum slick. The activity attracted a South Polar Skua, which came in and joined the group. Working back in toward the shelf, we found some patches of Sargasso Weed and we stopped to net some and show the passengers. It turned out to be a good place to be when a Fea's Petrel came zipping by the bow. This bird was much closer, but it did not linger. After that, it was time to head back toward the inlet. It was a nice ride in and we found an Arctic Tern and a few more shearwaters and jaegers. We even saw a Leach's Storm-Petrel five miles off the beach. I would like to thank all our our top notch leaders for their hard work- Kate Sutherland, Steve Howell, David Shoch, and Bob Fogg- all working together like a well oiled machine. I'm looking forward to tomorrow!  (Photos today are by Brian Patteson, Steve Howell, Dave Shoch, & Bob Fogg - thanks guys!!  Captions & list by Kate)

Bermuda Petrel  1
Fea's Petrel  1
Fea's/Zino's Petrel  1
Black-capped Petrel  25-30
Cory's Shearwater  50+
Great Shearwater  8-9
Sooty Shearwater  25
Audubon's Shearwater  30
Wilson's Storm-Petrel  150
Leach's Storm-Petrel  8
Band-rumped Storm-Petrel  5-6
Arctic Tern  1
Sterna sp.  2
Long-tailed Jaeger  5
jaeger sp.  2
South Polar Skua  2

OK, let's just get this out of the way first.  Here on the left is the interesting petrel, possibly a Zino's Petrel.  These birds were not extremely close to the boat, and the bird in question flew directly away from us.  Bob Fogg was able to get this photo.

And a few pictures of the Cahow!  First up, Brian Patteson:

& a very cool angle from Steve showing Brian taking one of these photos:

Dave Shoch:

Bob Fogg's Photos, first one shows the wing dragging the surface!

Black-capped Petrels (Steve Howell)

Cory's Shearwater (Bob Fogg)

 Cory's & Audubon's Shearwaters (Steve Howell)

Great Shearwater (Steve Howell)

Audubon's Shearwater (Steve Howell)

 Molting Band-rumped Storm-Petrel (Grant's) by Bob Fogg

South Polar Skua, it was very cooperative for over an hour!  (Bob Fogg)

 by Steve Howell

Atlantic Necromancer (Steve Howell)