9 Nov 2014

9 Nov 14 - A Pterorrific Day At Sea Off Henderson Island

After the excellent morning on Henderson Island where we saw Henderson Island Crake, Chris & Matt decided to spend the rest of the day revisiting the seamount about 20 nautical miles off Henderson Island: as it was so good on our previous visit. It was clearly being used as a feeding ground for several species of locally breeding Pterodroma Petrels, as well as Frigatebirds, Boobies, Noddies & White Terns. Despite seeing five species of Pterodroma Petrels on our first visit, we exceeded that total with an astounding nine species seen on the return visit: thanks to some excellent chumming by Elliot, along with a fish oil drip to attract the Seabirds.

There was a regular presence of mainly Murphy's Petrels off the back of the Braveheart with occasional appearances from Henderson Island Petrels, Herald Petrels & a Kermadec Petrel. Typically, the three Juan Fernandez Petrels I saw were all fly pasts (& you will have to wait for a future Post for photos of this species). One of the highlights was my seen first Phoenix Petrel. But the best point of the afternoon was an amazing 20 minutes when a Gould's Petrel (which breeds in Australia & New Caledonia) came into the fish oil slick. As it headed off for the bows, another pale Pterodroma appeared at the stern: a Stejneger's Petrel (which breeds on Alejandro Selkirk Island off the Chilean coast). This then headed off towards the bows (sadly never to be seen again) and as it did the Gould's Petrel was picked up again off the stern. Soon after the Gould's Petrel disappeared, a Cook's Petrel (a New Zealand breeding endemic) appeared in the chumming area. An amazing juxtaposition of Pterodroma Petrels. The depressions & poor weather of the last week had clearly had a positive effect on the Pterodroma Petrels (if not on my stomach at the start of the trip).
Phoenix Petrel: This is a medium-sized Pterodroma Petrel which looks like a Tahiti Petrel, but has a Herald Petrel jizz. The dark underwings & head with white lower breast & belly look similar to Tahiti Petrel, but it has a whitish throat & the bill isn't as heavy as a Tahiti Petrel. Additionally, it has pale bases to the underwing primaries & a pale panel that extends to the central inner underwing. Fortunately, some of the others got photographs which showed the pale throat
Phoenix Petrel:  This species breeds in the Phoenix Islands, Marquesas Islands, Line Islands & the nearby Oeno Island the Pitcairn group
Murphy's Petrel: This is a common regional breeding endemic which breeds in the French Polynesian Tuamotu & Austral Islands & the Pitcairn group (Henderson, Ducie & Oeno)
Murphy's Petrel: Many showed this pale ping legs with dark webs
Murphy's Petrel: Showing a good patch of white around the base of the bill & throat
Murphy's Petrel: But, the extent of pale below the bill was variable
Kermadec Petrel: Intermediate morph. Kermadec Petrels come in a confusing pale, intermediate & dark morph colourations. A dark morph was photographed as we approached Henderson on 8 Nov
Kermadec Petrel: Intermediate morph. The pale morph has an even whiter head. Intermediate morphs have pale brown mottling on the crown, collar & flanks, which darkens on the undertail. All morphs have this Skue-like white flash at the base of the upperwing primaries
Kermadec Petrel: Intermediate morph. Kermadec Petrels have a large, pale patch on the underwing primaries which extends onto the base of the underwing secondaries. Pale morphs also have a narrow pale line on the leading edge of the inner forewing (intermediate morphs are more variable in wing pattern than the pale morphs)
Kermadec Petrel: Intermediate morph. Intermediate morphs have a stronger collar & breast band than pale morphs
Herald Petrel: Intermediate morph. Most of the Herald Petrels looked like Pale morphs, but this shows a stronger breast band
Herald Petrel: Intermediate morph
Herald Petrel: Pale morph. Pale morphs have paler, less distinct breast bands & whiter undertail coverts
Herald Petrel: Pale morph
Herald Petrel: Up close & personal
Cook's Petrel: The main features are the white underwing with narrow black trailing edge & wing tip, black tick mark at the underwing carpel bar, uniform grey crown & nape with the grey not extending down to form a collar & small black ear patch
Cook's Petrel: A surprise to see this species as it should be breeding in New Zealand waters at this time of the year
Cook's Petrel
Gould's Petrel: The main features of Gould's Petrel is the dark hood which extends unbroken from below the eye to the sides of the breast, the white underwing with the broad trailing edge, the noticeable black line from the carpel which almost reaches the body, the dark wing tips & the white bases to the primaries
Gould's Petrel: There are two subspecies. This looks like the caledonica subspecies which has more white at the base of the underwing primaries
Gould's Petrel: As the caledonica name suggests, this subspecies breeds on New Caledonia
Stejneger's Petrel: This is a relatively small & slim Pterodroma with narrow wings, a long tail & a small bill. The small size was apparent as it came past the Braveheart. Plumage-wise, the white underwing with a slightly broader dark trailing edge & a larger black tick mark at the carpel patch. Additionally, the crown and nape are very dark with a small dark grey partial collar with a white crescent on the ear coverts
Stejneger's Petrel: This only breeds on Alejandro Selkirk Island in the Juan Fernandez Islands off the Chilean coast. My photos weren't brilliant, but fortunately, some of the others managed to get better photos of this individual

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