Sunday, November 6, 2016

Fremantle Pelagic Trip Report – 21 August 2016

Summary: An excellent day out started off with a small pod of Orca, including a large bull, just off Rottnest Island. We continued on to the head of the Perth Canyon for two berley and drift sessions with a good mix of eastern Indian Ocean birds, where the undoubted avian highlight was a single Atlantic Yellow-nosed Albatross. It left it late and only joined the birds on the slick for five minutes towards the end of the day. Other good sightings included a single Arctic Tern, two Southern Giant Petrels and up to 35 Soft-plumaged Petrels (including a darkish morph bird and several intermediate morph and streaked individuals).

Atlantic Yellow-nosed Albatross Thalassarche chlororhynchos off Fremantle Western Australia. The ‘puffin-like’ black triangles around the eyes made this Atlantic easy to pick out from the closely related and common Indian Yellow-nosed Albatrosses (photo: Plaxy Barratt)

Participants: Daniel Mantle and Plaxy Barratt (trip leaders), Alan Collins (co-organiser), Pauline Arnold, Damian Baxter, Ry Beaver, James Bennett, Bill Betts, Alan Bewsher, Mark Binns, John Cotton, Melissa Haynes, Lisa Ikin, Pat and Linda Kelly, Meghan Lagdon, Maris Lauva, Wayne Merritt, Geoff Morton, Robyn and Morgan Pickering, Nathan Piesse, Steve Reynolds, Bill Rutherford, Alex Soler, Ben Weston, Gavin White, Pauline Woolley, and Susan Young. Organiser-in-chief (in absentia) – John Graff.

Conditions: The day started with weak WNW winds and low swell (1-1.5m), but with predictions for a strong front to come through in the afternoon we were keen to get out to the deeper waters of the Perth Canyon as quickly as possible. The winds did freshen through the morning (WNW to NW) with occasional stronger gusts and accompanying brief rainy squalls, but the near-gale force NW winds forecast for mid-afternoon never materialised. All up, it was a very comfortable day on the water with the SW swell never exceeding 2m and only very low waves on top of this. The water temperatures in the Perth Canyon were measured at 18.4°C.




Report: We boarded the Jazz IV at the Sardine Jetty in Fremantle at 6.45am and met Drew Clowes (skipper) and Mattie (deckie) for their inaugural pelagic trip. We set up off in very placid conditions and were soon cruising along at a good speed out to and along Rottnest Island’s southern coast. An hour into the journey, at the far western end of Rottnest, we encountered our first Indian Yellow-nosed Albatross of the day, before the call went out for ‘Orca’! We had stumbled upon a loose pod of at least six Orca, including an impressive large bull. The pod was well spread out, with some individuals surfacing up to 500m from the small core group of 3-4 female/young male types. I don’t think we were ever certain of more than 6 animals, but there could easily have been up to 8-10 Orca in total. A single Cape Petrel was loosely associating with the Orca and a Welcome Swallow also put in a brief cameo. With strong winds predicted for the afternoon, we couldn’t hang around too long, and so we made the decision to leave the Orca behind and continue on to the head of the Perth Canyon.

A widely scattered pod of up to 8-10 Orca, including this impressive male, were encountered off the western end of Rottnest Island (photo: Plaxy Barratt).
              
Three of the female/younger male type Orca (photo: Steve Reynolds).
The next hour was relatively quiet with only a few Indian Yellow-nosed Albatrosses and Australasian Gannets for company, whilst a few observers also got on to four Hutton’s Shearwaters as we continued to make rapid progress out to the canyon. These were shortly followed by the first Soft-plumaged Petrels of the day as we approached the deeper water and the decision was made to stop and berley at the 750m mark (already 32 nautical miles from Fremantle). Within five minutes, we had a nice long tuna oil slick stretching away from us, that immediately drew in more Soft-plumaged Petrels and a lone Cape Petrel (quite a dark bird that may have been a contender for D. c. australe). The first dark-intermediate morph Soft-plumaged Petrel was soon called at the back of the boat, to be shortly followed by another paler grey intermediate morph with obviously stronger primary moult. It was soon apparent that we were seeing a large variation in wing moult amongst the Soft-plumaged Petrels - from near pristine birds to those with heavy primary and secondary moult (a lot of the birds were exhibiting mostly new primaries whilst just retaining the worn outermost 2-4 primaries). Also of interest was that the Soft-plumaged Petrels were often landing to feed in the slick, not something we often see them do.



Three Soft-plumaged Petrels Pterodroma mollis showing just some of the variation in moult and plumage (middle: dark morph) observed across the day.(photos: Dan Mantle).

A small flock of Silver Gulls had followed us out from Rottnest and were keeping most of the ‘real seabirds’ away from the choicest fish scraps and suet escaping the chum bag at the back of the boat. We challenged their appetite and fed them up on pilchards until they were mostly sated and settled nearby to digest their easy late breakfast and thus allow the petrels and albatrosses to approach closer to the boat. The numbers of Indian Yellow-nosed Albatrosses continued to grow, whilst our first Flesh-footed Shearwaters, White-faced Storm-Petrels, Northern Giant Petrel and Great-winged Petrel also appeared over the slick.
The increasing number of birds feeding over the chum attracted the attention of two Brown Skuas, one of which put in a good shift chasing a Soft-plumaged Petrel. It clearly had better straight line speed but it was never going to catch one of the more agile petrels, and after a determined effort it admitted defeat and returned to the easier pickings in the berley slick. Next up, the first of three immature Shy Albatrosses appeared, followed closely by an immature Black-browed Albatross that also wanted to join in the free lunch.


Brown Skua and Indian Yellow-nosed Albatross squabbling over scraps (photo: Plaxy Barratt).
Three immature Shy Albatrosses Thalassarche cauta paid us a visit through the day but none ever settled for long near the boat (photo: Melissa Zappelli)

As we continued to scan through the birds coming in to inspect the slick, the first of only two Wilson’s Storm-Petrels were picked up and then a ‘tern’ was called out as it approached the stern. It was identified, at the time, as an Arctic Tern by the long-winged buoyant flight, relatively short bill, and thin, well defined black trailing edge to the primaries, strong contrast between the white rump and grey back and the grey underparts. Photographs then seemed to confirm this identification – based on the black outer edges to the outer rectrices and narrow white wedge between the bill and dark cap. However, it was also noted that it lacked much obvious translucency in the primaries and was also showing obvious wing moult (mostly fresh primaries contrastingly strongly with the very worn P10). This led to online discussions considering the possibility of Antarctic Tern, but in the end everyone was happy with the original identification – Arctic Tern.



The relatively short bill, narrow white wedge between the bill and dark cap, dark outer edges to the outer rectrices and thin well defined black trailing edge to the primaries helped identify this bird as an Arctic Tern (photo: Dan Mantle).





Immature Northern Giant Petrel (red bill tip, bottom) and Southern Giant Petrel (greenish bill tip, top) provided excellent comparative opportunities (photo: Melissa Zappelli)

The slick continued to attract new birds and the number of Northern Giant Petrels built up to three individuals (two very dark immature birds and an older near-adult bird with some pale feathering around the face and a slightly paler, though not fully light eye), along with a single immature Southern Giant Petrel. The second Black-browed Albatross, this time an adult, also came in for a feed as the skipper readied the boat for the journey home. We managed to convince him that as the weather was holding, we still had plenty of time to spare and could spend another half hour with the slick. Luckily for us, he was more than happy to accommodate this request, and just ten minute later a fine Atlantic Yellow-nosed Albatross was picked up circling the boat. The very obvious ‘Puffin-like’ eyes (upside down black triangles) made it easy to pick the bird out among the thirty plus Indian Yellow-nosed Albatrosses. The slightly worn/bleached greyish-brown hood (strongest on the hindneck) and the yellow culminicorn stripe broadening above the nostrils and terminating with a blunt rounded tip were enough to confirm the identification. This bird will represent only the 5th record to be submitted to BARC, but in reality there are probably closer to 8-9 confirmed sightings in Australia. It was a major highlight to an already fun day out.

Although this Atlantic Yellow-nosed Albatross did not have a particularly dark grey hood, it was still readily apparent on the hindneck of the bird and even across the lower neck and throat in the correct light (photo: Plaxy Barratt).

Comparison of the yellow culminicorn strip on Indian Yellow-nosed Albatross (on left) and Atlantic Yellow-nosed Albatross (on right). Note on the Atlantic Yellow-nosed Albatross how the yellow culminicorn stripe broadens above the nostrils and terminates in a blunter more rounded tip by the forehead. (photo: Steve Reynolds)

It was time to head back to Fremantle, but there was still time for a final short chumming session off the western tip of Rottnest. Although the Orca weren’t to be seen again, we did entice a final Soft-plumaged Petrel, Cape Petrel and the second Southern Giant Petrel of the day to have a feed in the now quite rainy, squalling conditions only a kilometre from Rottnest Island. This was to be the final birding for the day and we arrived back at the Sardine Jetty by 3pm.
A major thanks to John Graff for organising this trip (and commiserations on missing a good bird in your own ‘backyard’) and to Drew and Mattie of Jazz Charters for operating a very comfortable and accommodating day out aboard the Jazz IV.

Species list [Total seen (max seen at one time)]
Australian Shelduck 2 (2)
Black-browed Albatross 2 (1)
Shy Albatross 3 (2)
ATLANTIC YELLOW-NOSED ALBATROSS 1 (1)
Indian Yellow-nosed Albatross 60 (38)
Northern Giant Petrel 3 (3)
Southern Giant Petrel 2 (1)
Cape Petrel 3 (1) – one possible contender for D. c. australe
Great-winged Petrel 2 (1)
Soft-plumaged Petrel 35 (9, incl. dark morph bird and several intermediate morph)
Flesh-footed Shearwater 8 (3)
Hutton’s Shearwater 4 (4)
Wilson’s Storm-petrel 2 (1)
White-faced Storm-petrel 10 (3)
Australasian Gannet 20 (6)
Pied Cormorant 7 (2)
Silver Gull 15 (8)
ARCTIC TERN 1 (1)
Great Crested Tern 7 (1)
Brown Skua 2 (2)
Welcome Swallow 1 (1)

Mammals:
Orca 6+ (possibly as many as 8-10 animals) – one large bull and several female/young male types off the western tip of Rottnest Island
Indo-Pacific Bottlenose Dolphin 1 (1+) –  off the SE corner of Rottnest Island
Humpback Whale – blows seen south of Rottnest on way out and way back in.








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