13 Apr 2018

13 Apr 18 - Atlantic Odyssey - Day Sixteen: The Curse Of Friday 13th

I was up earlier than normal today as the plan was to land on Nightingale Island in the Tristan da Cunha group. This is an amazing island & one that I was really looking forward to visiting. It is uninhabited, but it contains a number of huts which are owned by Tristan da Cunha families as they regard Nightingale Island as their holiday island. It is really a fantastic place for Birding as the island is full of nesting Seabirds including 2 million pairs of Great Sheatwaters & Yellow-nosed Albatrosses. However, the other interest was the chance to look for the island's Passerines: Tristan Thrush, Nightingale Finch & Wilkins's Finch. The two Finches look similar in colouration to the Gough Bunting i.e. a pale yellow-olive Finch. However, whilst Nightingale Finch has retained a relatively normal bill, the Wilkins's Finch has developed a very heavy bill. I guess they could be considered the Tristan da Cunha equivalent of the Darwin Finches of the Galapagos.
Nightingale Island: Large waves were breaking against this rugged island. The island is about a 1.5 miles by 1 mile
The plan the evening before was that there would be a landing & the chance for the fitter people to walk up to the higher elevations of the island to look for Wilkins's Finch. It should be possible to see the Nightingale Finch & Tristan Thrush (which is noticeably darker than the subspecies on Tristan da Cunha) at lower elevations. It wasn't expected to be an easy walk as initially there is a steep muddy path up from the beach (with a rope to hang onto to help the ascent), followed by a walk through head high grass along a path that probably hadn't been walked this year. The Petrels group were planned to be first to land & we had requested that the first zodiacs would contain those Birders who were wanting to get up to the higher parts of the island. I went to bed with high hopes for the morning on Nightingale Island & ready to be on the first zodiac.
Nightingale Island: A zodiac was launched to see if it was possible to get in the zodiacs
Sadly, it all came to nothing. As the Plancius approached the island, it was clear that the swell was too bad to be able to get the zodiacs into the water & land at one of the two safe landing sites on the island. We were told we would have to make do with a circular cruise around Nightingale Island from the Plancius. I was deeply disappointed as had heard great stories from other Birders who had been lucky to land on Nightingale Island. However, when I was reading trip reports from previous Odyssey trips, it was clear that the weather in the South Atlantic was likely to stop landings or zodiac cruises on at least one day around South Georgia, Gough Island & the Tristan da Cunha islands. So far, we had been successful with all planned landings or zodiac cruises & therefore, the odds were against us for this final landing in the Tristan da Cunha islands. Being Friday 13th didn't help for those who were superstitious.
Scanning from the top deck
It was a case of trying to find a good viewpoint & scanning the island from the Plancius. By now I was starting to regard the bridge wings as my daytime home, But I had to consider also finding a position where I wasn't too far from a mate with a scope & tripod. Realistically, we were too far to use the bins to try picking out the Passerines onshore. There were various individuals who were getting brief views of a larger (Tristan Thrush) or smaller (Nightingale Finch) Passerine along the rocks or around the huts. I did get the chance to borrow a scope for a few minutes, but I failed to get onto any Passerines.
Inaccessible Island: It lived up to its name today. This is the only breeding island for Spectacled Petrels and it also hosts another 2 million pairs of Great Shearwaters
After the zodiac cruise around Nightingale Island we carried on to circumnavigate Inaccessible Island. It was clear that it would live up to its name today & that we would not get the chance to get the zodiacs into the water here either. Landings on Inaccessible Island are very rare & zodiac cruises are not common here either. In addition to the different subspecies of the three Passerines found on Nightingale Island, there is also the small flightless Inaccessible Rail on the island. Despite a lot of scanning from the Plancius, there was nothing seen apart from the occasional brief glimpses of a Tristan Thrush (which I didn't get to see).
Inaccessible Island
Having circumnavigated Inaccessible Island, we headed back to Tristan da Cunha, to drop the islanders who had been our guides. It was disappointing, but all zodiac landings & cruises are down to the state of the weather & it was clearly not feasible today: c'est la vie. We quickly dropped the islanders, loaded some fresh lobsters (for the non vegies), some potatoes (for me) & extra beer. Then it was time to start heading North West as we had another 4.5 days of sailing until we reached our next island of St Helena. We still had an afternoon of Birding so after lunch we were back on deck for some seawatching. There was a good selection of the same Albatrosses, Shearwaters & Petrels we had been seeing on the previous few days. However, the most interesting Birds were seeing reasonable numbers of White-bellied Storm-petrels. We had seen Storm-petrels with white-bellies when we were around Gough Island and approaching Tristan da Cunha, however, these had been the 'White-bellied' subspecies of Black-bellied Storm-petrel. Finally, we had some White-bellied Storm-petrels for comparison.
White-bellied Storm-petrel: The leucogaster subspecies breeds on the Tristan da Cunha Islands and perhaps Gough Island. White-bellied Storm-petrels have shorter legs that do not significantly extend beyond the tail. They also have a concave black undertail coverts pattern so the white belly is also curved
White-bellied Storm-petrel: Another view of the same individual confirming the short legs
White-bellied Storm-petrel: A closer crop of the same individual showing the shorter hood of White-bellied Storm-petrels & the shape of the white belly & black undertail coverts
White-bellied Storm-petrel: A second individual with short legs, the narrower hood & the vent/undertail pattern
White-bellied Storm-petrel: Another view of the second individual. They have a narrower rump patch with dark spotting to the longest uppertail coverts: unfortunately, I didn't manage to get a good photo of the rump
White-bellied Storm-petrel: A final individual
White-bellied Storm-petrel: Another view of the final individual
White-bellied Storm-petrel: The last photo of the final individual
A few days earlier we were lucky to have an excellent talk from fellow passenger, Bob Flood, on the identification of White-bellied Storm-petrels & 'White-bellied' Black-bellied Storm-petrels in the Atlantic: which made this difficult subject seem more straight-forward. One potential feature that Bob may have missed it White-bellied Storm-petrels prefer to fly over areas of bright blue sea, whereas 'White-bellied' Black-bellied Storm-petrels prefer grey seas.
Bob Flood giving his excellent talk on the identification of Storm-petrels with white-bellies: (8 Apr 18)
'White-bellied' Black-bellied Storm-petrel: The melanoleuca subspecies breeds on Gough & the Tristan da Cunha Islands. This one doesn't seem to show the long feet. Black-bellied Storm-petrels also have a larger hood & a clean square cut off between the white belly & the black undertail coverts. Approach to Gough Island (9 Apr 18)
'White-bellied' Black-bellied Storm-petrel: The same individual seen on the approach to Gough Island (9 Apr 18)
'White-bellied' Black-bellied Storm-petrel: Showing the longer legs which clearly extend beyond the tail in flight seen off Gough Island (10 Apr 18)
'White-bellied' Black-bellied Storm-petrel: Seen off Gough Island (10 Apr 18)
'White-bellied' Black-bellied Storm-petrel: The rump size does seem to be variable on these 'White-bellied' Black-bellied Storm-petrels. This also shows the clearly long legs seen off Gough Island (10 Apr 18)

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