17 Apr 2018

17 Apr 18 - Atlantic Odyssey - Day Nineteen: At Sea From Tristan Da Cunha To St Helena - Stormies

Today was the final day at sea before we arrived at St Helena. There was more expectation from the passengers that we would see more Seabirds & more people on deck looking.
Los Bandidos (John & Jemi Holmes): John has been publishing a number of Blog Posts of the Odyssey which can be found here. It is well worth a look as John is a great photographer
Hadie (left) & Roy confirming that the benches on the top deck behind the bridge were still popular
Yorkshire Geoff Dodds: My cabin mate had finally left editing the Yorkshire Bird Report & appeared in the sun
An early morning small party of Dolphins looked promising as they were heading straight for the Plancius. We were all hoping for some bow waving, but clearly, they had other ideas as this was the best photo I obtained & we lost them soon after picking them up.
Dolphin sp.: You can't win them all
As we were approximately 250 nautical miles from the St Helena at dawn, we were still out in the deep oceans & would remain so for the rest of the day. Consequently, it was still a fairly quiet day at sea for Seabirds. I saw more individuals than than on the last two days put together, but that wasn't hard given I had only seen nine Seabirds over those two days. The commonest species were Arctic Terns which were moving North, but all remained distant. There were also a few Red-billed Tropicbirds seen during the day, including one which came overhead to check out the Plancius.
Red-billed Tropicbird: The could be briefly very inquisitive of the Plancius
Red-billed Tropicbird: This is the nominate aethereus which occurs on the offshore Brazilian island of Fernando de Noronha, as well as, St Helena & Ascension Island
The Seabird highlight occurred late morning as we picked up a party of six Storm-petrels resting on the sea a few hundred metres in front of the Plancius.
Mixed party of Storm-petrels resting on the sea
Mixed Storm-petrel party taking off: They didn't have a choice as they were right in the path of the Plancius
Band-rumped Storm-petrel: Band-rumped Storm-petrels have until recent years been considered to be a single subspecies. However, given two species have now been split so far, then it is worth seeing them at as many breeding islands as possible. Given we are within a day of St Helena, then it is a reasonable assumption this is one of the St Helena population. However, it is safer to see them at one of the St Helena colonies to be certain, in case St Helena Storm-petrel is split in the future. Identification of these Band-rumped Storm-petrel & related species at sea, well away from breeding grounds is in its infancy
Band-rumped Storm-petrel: Another view of the same individual
Band-rumped Storm-petrel taxonomy is complex. A few years ago, Band-rumped Storm-petrels were understood to breed on islands in the Tropical Atlantic & Pacific Oceans including the Portuguese Berlengas Islands, Madeira, Canaries, Azores, Cape Verde, Ascension Island, St Helena, as well as, the Galapagos, Hawaii & islands belonging to Japan. In the last decade, studies into the breeding times of year, DNA, vocalisation & morphology have identified that there are probably three additional species which breed on the Tropical North Atlantic islands. Further studies are now underway to extend these studies into some of the other Atlantic populations of Band-rumped Storm-petrel & it is likely that this will reveal additional species when these studies have been completed. The current understanding of the former Band-rumped Storm-petrel species is:-
  • Cape Verde Storm-petrel (Oceanodroma jabejabe) breeds in Cape Verde from Oct to June
  • Monteiro's Storm-petrel (Oceanodroma monteiroi) breeds in the Azores in Mar to Oct
  • Band-rumped Storm-petrels (also known as Madeiran Storm-petrel) (Oceanodroma castro) breeds around Madeira including the Desertas Islands, the Salvagens Islands & the Canaries in Mar to Oct
  • Grant's Storm-petrel (Oceanodroma granti) breeds in the Berlengas Islands, Madeira & the Canaries & associated islands & Azores in Aug to Mar. This has been proposed as a future split (but is yet to be described)
  • Studies of the Band-rumped Storm-petrels which breed on Ascension Island & St Helena are only just starting.
A single Leach's Storm-petrel (top left) was tucked into the group of five Band-rumped Storm-petrels
Leach's Storm-petrel: Close up from the last photo. Note, the strong pale wing panel, deeply forked tail & dark central rump band
Leach's Storm-petrel (top left) and Band-rumped Storm-petrels: The Band-rumped Storm-petrels have square-ended tails & white rumps & also show a noticeable pale wing panel. They seem to have shorter wings than the Leach's Storm-petrel
Leach's Storm-petrel (top left) and Band-rumped Storm-petrels: Note, how the pale wing panel
Leach's Storm-petrel (top left) and Band-rumped Storm-petrels: The stripe in the rump of the Leach's Storm-petrel is clearly obvious