SKUAs in the GOM (2014 - 2018)

Here is a summary of our recent trips (since 2014) across the GOM Gulf Of Maine, and SKUA sightings:

On our regularly scheduled HAS GOM Gulf Of Maine field trips (between Portland ME and Yarmouth NS Canada) we have seen skuas on every trip which sailed. The ferry was the 500ft Nova Star in 2014 and 2015, and the 300ft new CAT in 2016-2018.

This trip has pros and cons. Here are two...
Pro: it is a long route (212 miles crossing each way), so there is plenty of opportunity to find birds in the exciting GOM.
Con: this is a public ship and it does not chase birds, so most of our skua photos had to be taken at very long distances.

Note that in 2016-2018 our Great Skuas photographed (between Sept.17 and Oct.8) all displayed molting in the primaries (obvious from the break in the white areas of the primaries), consistent with a bird breeding in the northern hemisphere, not with one breeding in the southern hemisphere and heading home/south in late Sept/Oct.  This is extra confirmation that these birds were Stercorarius skua, not a southern-breeding skua.

2018: two Great Skuas.

2018 October 7-8 two-day GOM Skua trip

This distant skua #2 (dorsal view) photographed by our team member Severin Uebbing on 2018-10-07 at 4:03pm EDT in GOM, in US waters...

Weather forced postponement of trip to Sunday-Monday, resulting in most of team withdrawing from the trip.  Our remaining 2018 team, two geneticists, Severin Uebbing (left) and Alex Lin-Moore (right), and yours truly...

2017: two Great Skuas, one South Polar Skua, two Skua sp.

Sept. 29-30 GOM Pelagic Trip RESULTS
This photo by our team member Bill Asteriades. Note the gold streaking on the dorsum/back (mantle and scapulars, distinguishing it from a South Polar Skua)...

Our 2017 team...Richard, Peg, Charles, Eduardo, Bill, Joe and Tom...

2016: two Great Skuas.  Our first year on the new CAT ferry.

2016 September 17-18 Great Skua YES

2016 September 12-13 Reconn trip for 9/17-18

This photo by our team member Dave Pettee...

Our 2016 team: Dave Pettee (from MA), Nicole Giambro (MA), Christine Howe (from CT/HAS), Dan Nickerson (ME), Anthony Laguidara (MA), and photo by Tom Robben (CT/HAS)...

2015: trip cancelled by extreme weather.

2015 Nova Star & HAS trip on GOM Cancelled!!

Ferry company cancelled the sailing because of weather.  No photo of any skua.

2014: one Great Skua, 3 Skua sp.

2014 Oct 11-12 GOM Marine & Seabird Survey

This 2014 trip was our first on this new NovaStar ship, which then had a two-year run on this route. We saw several skuas but our team got no usable photos. Here is our 2014 team that weekend:   S.Schiesser, T.Robben, C.Pryor, S.Robben, K.Powers, R.Harrison, W.Petersen, and in front: F.Mantlik, K.VanDerAue, N.Levenduski and P.Comins.

Our multiple other GOM crossings over the last five years have recorded skuas the majority of times. Here are some...

2015 October 8 GOM crossing with Bigelow Lab
Including Barney Balch and Dave Drapeau.
Skuas were not looked for and not seen. 

2015 Sept 23 GOM pelagic trip
3 Great Skua seen, but not photographed.
Our team included HL Heather Leslie, LB Louis Bevier, PB Pam Bragdon, TR yours truly, JR Julie Reimer, JK Jordan Killkelley and Robbie Lambert (not shown, surveying birds from the bridge)...

2015 August 5.   No skuas on this August 5th GOM crossing...
2015 August 5th Gulf of Maine on the Nova Star - Google Docs

Team included Iain Stenhouse, Julie Reimer and yours truly. 

2015 June 27-28 Nova Star trip - Google Docs

2015 June 27-28 ECO : Everyone Cares about the Ocean
We saw one skua species, but no photos were captured by our team (Kevin Powers, Frank Mantlik, yours truly, Eric Mills, Les Kaufman, Dave Drapeau)....

This was a memorable trip, where the weather got quite rough on the June 28 return leg, as you can see from this photo, looking down from about 60 feet above the bounding main...

but the hardy seabirders (Eric Mills, Les Kaufman and Kevin Powers in red) continued to "rough it", mercilessly forcing themselves to eat the good food onboard the NovaStar... including the delicious blueberry cheesecake on my plate... while we exhausted ourselves strenuously bird-watching out the side windows at our breakfast table, where a South Polar Skua was spotted a few minutes later, as it fought the wind and rain...

I also took several GOM crossings in 1960-1970's but skuas were more difficult to find (not as regular).

On Nov.13th, 2018  I gave a presentation about Skuas (Stercorarius skua and five southern forms) and other marine matters. An updated version of that presentation will be posted here in several weeks. Thank you.

2018 November 13 Skuas Presentation

THIS POST IS A WORKING DRAFT -- UNDER CONSTRUCTION:

On Nov.13th I gave a presentation about Skuas (the six large Stercorarius [formerly genus Catharacta] forms, including S.skua and five other/southern forms/taxa) and some other marine matters. An updated version of that presentation will be posted here in several weeks. Meanwhile here are selected hi-lights, along with an outline of it. Thank you. Tom



Note Peter Harrison's 1983 view of the six skuas, from the 1988 Alan Brady article:

Click on any of the following images to enlarge them. Then press ESC key to return...

Adapted from Ian Lewington, Handbook of the Birds of the World - Volume 3

Breeding ranges of the five southern forms of Skuas (excluding the Great Skua, the 6th and northern form of skua):

From Ritz, Marcus et al. Phylogeography of the southern skua complex - rapid colonization of the southern hemisphere during a glacial period and reticulate evolution. 

The presentation is mostly about the history of this Stercorarius genus (the six big skua forms/taxa originally constituted the genus Catharacta, until recently being moved into Stercorarius with Jaegers), and how our understanding of them has changed over the years, since the first skua was collected and named in 1764, Catharacta skua, aka Great Skua....
1758.   Parasitic Jaeger.
1764.   Great Skua (skua, breeds in the eastern North Atlantic).
1815.   Pomarine Jaeger.
1819.   Long-tailed Jaeger.
1831.   Brown Skua (antarcticus, in the Falkland Islands and on Argentina coast).
1841.   South Polar Skua (maccormicki, on the Antarctic continent, and called MacCormick's Skua originally).
1857.   Chilean Skua (chilensis, in southern South America).
1912.   Subantarctic Skua (lonnbergi, on subantarctic islands). Now considered a subspecies of Brown Skua.
1952.   Tristan Skua (hamiltoni, at Gough & Tristan da Cunha). Now considered a subspecies of Brown Skua.

NOVEMBER 13 PRESENTATION, AS PLANNED:
The November 13th presentation was completed, but thanks to computer glitches we did not have enough time during the 11/13 meeting to present 100% of the following planned and prepared material, outlined here...

PELAGIC BIRDING TRIPS AND SKUAS:
-- including several recent HAS cross-GOM trips, photos, videos, etc.   SKUAs in the GOM
-- with some of our trip videos:  Great Skua 20181008 1103am c0010 - YouTube
-- the difficulties of skuas, such as, most keep their distance from ships.
-- equipment and methods, including telephotography and 4k videography.  4K resolution
-- improved continuous AF autofocus for extreme telephotos: Sony DSC-RX10M4
-- current and historical pelagic birding trips in the Atlantic (an active research project).
-- the best waters for seabirds, around the globe, e.g., Humbolt (Peru) Current, Benguela Current.
-- some good examples: Monterey CA, Hatteras NC, Simon's Town S.Africa, etc.
-- favorite rough inlets, e.g.,  Jones Inlet, NY - YouTube  and  Oregon Inlet, NC - YouTube

THE HISTORY OF SKUAS:
-- the Family Portrait of all skuas.
-- with some ancient history of taxonomy, systematics and museum expeditions.
-- some history of commercial fishing (and regulation changes) in the Atlantic.   Factory ship and History of the groundfishing industry of New England (Kevin Powers is an expert on this).
-- 1970s recognition of South Polar Skua in the Northern Hemisphere! With multiple articles.
-- a milestone in skua history in 1974:  Bob Paxton, Paul Buckley and Tony Lauro saw one of the first few (probably the second!) South Polar Skuas (C.maccormicki at the time) eventually accepted in the North Atlantic in retrospect, during our third running of our novel Captree LI, NY "summer bird count" (Christmas Bird Counts as Breeding Bird Censuses) .... note Bob's penciled comment in his field notes from that day, next to Great Skua [in June!], "(PAB left thinking it a C.maccormicki)"...

SPECIATION AND HYBRIDIZATION:
-- which of the six skua forms hybridize with each other.
-- and the limits of ribosomal DNA/RNA - the latest debate.
-- how to define "species"?

IDENTIFICATION OF SKUAS:
-- with the many plumages and variables influencing them, including molting & molt timing.
-- plus occasional confusion with the closely related dark morph Pomarine Jaegers.

SKUA LIFE CYCLE & THE MARINE FOOD WEB  (the marine science section of this presentation):
-- from january to december - the parallel seasonal cycles.
-- one year in the ocean (tracking 2 skuas, 1 Sabine's Gull, and several other seabirds month-by-month, around the world, and through the ocean ecosystem).
-- our efforts to sample & photograph fish, plankton, etc.  our video camera just under ocean surface
-- skua's place in the marine food web and the whole ecosystem.
-- from the microbial loop to the macro predator - food chains & microbial oceanography.
-- learning the pivotal importance of marine bacteria and viruses.
-- is the microbial ocean a stable virus-limited system?  does it have a tipping point?

SKUAS IN THE NORTH ATLANTIC:
-- looking at the reports and the evidence - are we overlooking another (3rd) skua species in the Atlantic?
-- hunting for another species of skua (and how to identify it)!

REFERENCES:  here are a few of the many references which were used...
-- Brady, Alan. Possible presence of an Antarctic Skua in New Jersey waters. 1988. DVOC.
-- Eggleston, Erin and Ian Hewson. Abundance of Two Pelagibacter ubique Bacteriophage Genotypes along a Latitudinal Transect in the North and South Atlantic Oceans. 2016.  Frontiers in Microbiology.  Recent field research on viruses in the Atlantic microbial ecosystem.
-- Helmreich, Stefan. Alien Ocean. 2009.
-- Labonte, Jessica M., et al.  Single-cell genomics-based analysis of virus–host interactions in marine surface bacterioplankton | The ISME Journal. Nature, 201548.
-- Pinkerton, Matt and Janet Bradford-Grieve. Network-characterisation-of-the-food-web-of-the-Ross-Sea-Antarctica-June-2012.pdf  CCAMLR Science.
-- Ritz, Marcus et al. Phylogeography of the southern skua complex - rapid colonization of the southern hemisphere during a glacial period and reticulate evolution. 2008. Molecular Phylogenetics and Evolution.


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HERE IS SOME OF THE MATERIAL FROM THE MARINE SCIENCE SECTION of the presentation:

Part of the presentation focuses on how skuas fit in with the complete marine ecosystem, and includes the following slides, discussed in the context of the presentation:

Where it all starts - the microbial ocean!
Our recently evolving understanding of this fundamental marine ecosystem, including the underestimated importance of mixotrophs.
How skuas and everything else in the marine system hinge on this micro sub-system and its presumed stability...

PHYTOPLANKTON:

Phytoplankton, also known as microalgae, are similar to terrestrial plants in that they contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean, where sunlight penetrates the water. Phytoplankton also require inorganic nutrients such as nitrates, phosphates, and sulfur which they convert into proteins, fats, and carbohydrates.

The two main classes of phytoplankton are dinoflagellates and diatoms.

What are phytoplankton?  They are microscopic marine algae.

ALGAE:

Algae are simple plants that can range from the microscopic (microalgae), to large seaweeds (macroalgae), such as giant kelp more than one hundred feet in length. Microalgae include both cyanobacteria, (similar to bacteria, and formerly called “blue-green algae”) as well as green, brown and red algae. (There are more varieties of microalgae, but these are the main ones.)

Algae Basics - All About Algae

Note that algae are polyphyletic….
Is it any wonder that people seem confused by what ALGAE are, what "algae" means?

Polyphyly and Convergent Evolution:  Algae is a polyphyletic group...
Click on any of the following images to enlarge them. Then press ESC key to return...

Higher up the Antarctic food web... we need to detail how each skua form fits-in slightly differently, e.g., lonnbergi preys on penguins (eggs and chicks) more, maccormicki preys on fish more...

During the year many marine components and variables go through seasonal cycles, starting with sunlight angle & duration, wind, water currents, air temperature, sea temperature (SST sea surface temp and temperatures at lower depths), rain/snow, watershed runoff, DO dissolved oxygen, various virus and bacteria blooms, various phytoplankton blooms, various zooplankton blooms,  etc.  How do the northern and southern skuas fit into these cycles? Are they mostly coupled to the zooplankton blooms, through intermediary cycles of fish of several sizes?

QUESTIONS:
There are many interesting questions related to all this material.  Will list some of them here....