Sunday, June 30, 2019

June 28 & 29, 2019 - Gadflies and Mesoplodons - by Kate Sutherland

This Friday and Saturday set turned out to be excellent for seabirds in spite of quite calm conditions and excellent for cetaceans because of the calm conditions!  Light to little wind and the hot, blue water of the Gulf Stream close to the shelf break made it feel like late July out there.  The water, though, was full of life with flyingfishes and scattered Sargassum all the way out to the deep.  A handful of large shearwaters were present on our way to the shelf break each morning, then we picked up all of the usual species offshore in our chum or sitting on the water: Black-capped Petrel, Cory's, Scopoli's, Great, and Audubon's Shearwater, plus Wilson's and Band-rumped Storm-Petrels!  Friday we also found Sooty Terns feeding over some mahi (Atlantic dolphinfish) and an adult Bridled Tern perched on some flotsam (photo by Kate Sutherland),
while Saturday's trip found Leach's Storm-Petrel and a second summer Long-tailed Jaeger - pretty nice list of our regular suspects for the two day set!

Friday's highlight came just after 0900 when Brian spotted a flock of Black-capped Petrels on the water ahead of us.  Leader Ed Corey, up in the bow pulpit, spotted a dark gadfly on the edge of the flock...  And as they flushed, a dark morph Trindade Petrel picked up from the water and flew right towards the boat!  It came in low, flew right down the starboard side, and away, no amount of chum would bring it back, but we had an excellent view (photo Kate Sutherland).
Saturday's highlight also came in the morning, but in the 1000 hour.  A beaked whale popped up right off the port bow!  As we searched for it to resurface, we saw at least four come up ahead of the boat!  Mesoplodon europaeus, commonly known as Gervais' Beaked Whale, is a species that we see regularly on our pelagic trips from Hatteras, but one that is not well known.  They are small, toothed whales typically found in deeper waters, and they dive for long periods of time, feeding at depth on squid and other deep water species.  We were lucky to catch this group as they surfaced and they were around the boat for at least 30 minutes before they sounded again.  The clarity of the water made it possible to see them well under the surface and for the first time, we had them come in under the bow when we were moving and "ride" the bow wave!  They were very curious about us, coming close and turning to look at us, swimming under the pulpit and checking out the stern (photo Brian Patteson).
It was the best encounter we have ever had with this species!  I want to make it clear that we were not chasing down or harassing these animals in any way, they came to us as we motored around and also sat and drifted.  In the time we spent with this pod, we moved about 1.5 miles over the bottom in the swift, Gulf Stream current, and the water temperature was about 84.5 degrees Fahrenheit.  There was at least one male in the group and his teeth were easy to see under water as were the fresh scratches on his back, presumably made by another male of the same species.  The other three individuals did not have visible teeth, making them females or young males.  It seemed that there were at least two adult females present, with one individual that looked larger than the others.  Their behavior was also interesting, they were turning over to show their bellies and sometimes swimming upside down or on their side at the surface (photo by Brian Patteson).
Perhaps one of the females was in estrus and this was why the male was present with this group?  Typically when we encounter groups of these animals they are all female or young individuals.  Who knows?  Little is known about the behavior of this species, so each chance we have to observe them is incredibly special.  As we watched the pod, a large container ship was approaching...a reminder of the intense noise pollution these whales face even out in the deep blue.

We have added a trip to the summer schedule next weekend, Saturday July 6, and the next scheduled trips will run at the end of the month: July 26 & 27, space is open on all three in addition to our August trips.  Join us!  Gulf Stream Trip Schedule

Thank you to Ed Corey for helping Brian and I lead these trips and contributing photos, and thank to also to David Miller for organizing and bringing a group with us on Friday's trip!

Species List June 28 / 29
Trindade Petrel - 1 / 0
Black-capped Petrel - 20 / 21
Cory's Shearwater - 5 / 5
Scopoli's Shearwater - 6 to 7 / 3
Cory's type - 26 / 29
Great Shearwater - 40 to 42 / 34
Audubon's Shearwater - 18 / 15
Wilson's Storm-Petrel - 45 to 50 / 60 to 65
Leach's Storm-Petrel - 0 / 6
Band-rumped Storm-Petrel - 10 to 12 / 22 to 25
Sooty Tern - 6 / 0
Bridled Tern - 1 / 0
Long-tailed Jaeger - 0 / 1

Risso's Dolphin - 0 / 12
Atlantic Spotted Dolphin - 8 to 9 / 0
Bottlenose Dolphin (offshore) - 40 to 45 / 0
Bottlenose Dolphin (coastal) - 0 / 30
Gervais' Beaked Whale - 0 / 4

Dorsal view of the Trindade Petrel (Kate Sutherland)
Saturday we found some flocks with Black-cappeds and storm-petrels on the water, the stormies here are all Wilson's (Kate Sutherland)
& it was cool to watch them take off!  (Kate Sutherland)
We had a few that made nice passes by the stern to check out the chum as well!  Here is an intermediate individual above and a dark-faced individual below (Kate Sutherland)
Both Cory's (Ed Corey) and Scopoli's Shearwaters (Ed Corey, top, Kate Sutherland bottom) were seen well on each trip, though we had more Scopoli's on Friday!
Great Shearwaters followed us, diving and feeding in the chum on both trips! (Kate Sutherland, Ed Corey)
While we didn't see many Audubon's, we did have a few that sat on the water for us to approach, everyone had good views! (Ed Corey)
Wilson's were not around in large numbers, but we did attract a few to the chum each day! (Kate Sutherland)
Saturday we had a handful of Leach's (Ed Corey)
Band-rumped Storm-Petrels are beginning to show here in larger numbers, as is expected in the summer months!  (Kate Sutherland, bottom photo by Ed Corey)
The Risso's Dolphins were a treat, there were some young individuals in this pod!  We haven't seen this species in a couple of years.  Top photo by Ed Corey showing the scarring on and adult, blunt head shape seen in the middle photo by Kate Sutherland, and the diagnostic dorsal fin shape is seen well in the bottom photo by Kate Sutherland.  Also called Gray Grampus
Atlantic Spotted Dolphins put on quite a show inshore of the shelf break on Friday morning!! (Kate Sutherland)
And because we just cannot resist photos of these Mesoplodon is a small photo gallery:
top photo showing the erupted teeth of the one male individual, bottom and individual without teeth showing - likely a female, though young males do not show these teeth until they are mature (photos by Ed Corey).
The following photos are all by Brian Patteson.  Showing how close they came to us!  Pictured is Murray Scott of Australia who is birding with John Weigel for a few weeks here in the US.  Incredible to watch these whales for so long!
Here you can see the scaring of the male individual - which look to be marks from a shark!  Not another male.
A nice view of three surfacing
A female with the male swimming below
Gorgeous head on view
And a view, tail end, of one of the females on her back, showing her tail flukes (Kate Sutherland).  While it is not easy to see in this image, there is another whale below her.
And the flyingfishes...well, there were a lot of them out there over these two days!  Here are a couple of images (Kate Sutherland)

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