Rare seabird sightings from a pelagic longline vessel off South Africa, July-September 2013 Dominic P. Rollinson Observations d’oiseaux de mer rares au large de l’Afrique du Sud a partir d’un palangrier en juillet- septembre 2013. L’auteur rapporte des observations d’oiseaux de mer rares ou peu communs, effectuees au large de l’Afrique du Sud pendant un voyage de 79 jours a bord d’un palangrier. La plupart des observations concernent des especes sub-antarctiques qui sont normalement confinees aux eaux plus froides au sud, mais qui s’aventurent occasionnellement plus au nord, surtout pendant l’hiver et le printemps australs. Quelques especes qui sont supposees frequenter les eaux sud-africaines uniquement au passage ont egalement ete notees. Ces observations indiquent que certaines especes d’oiseaux de mer rares pourraient frequenter les eaux sud-africaines plus souvent qu’on ne le pensait. Summary. This paper reports several rare and scarce seabirds recorded off South Africa during a 79-day trip on board a pelagic longline vessel. Most sightings were of subantarctic species that are normally restricted to colder waters further south, but are known to occasionally venture north, especially during the austral winter and spring. A few species which are thought to enter southern African waters only on passage were also observed. These sightings suggest that several rare seabird species may occur more frequently in South African waters than previously thought. T he productive waters off South Africa and a 300-mm telephoto lens. Records of species provide rich foraging opportunities for a observed within South African waters and number of seabird species (Ryan & Rose 1987). considered national rarities were submitted to, Approximately 60 species of Procellariiformes and have been accepted by, the South African have been recorded within the southern African National Rarities Committee. For some of the subregion, many of which are considered rare more frequently encountered species (Wandering vagrants (Hockey etal. 2005). Seabird diversity and Diomedea exulans, Northern Royal D. sanfordi and numbers increase during winter and spring, when Southern Royal Albatrosses D. epomophora and numerous subantarctic breeding species escape the Grey Petrel Procellaria cinerea) daily counts were colder conditions of high latitudes and forage in conducted which were summed to give a total the temperate waters off South Africa (Crawford et count for the entire trip. It is probable that the al. 1991). Here I report on rare seabirds observed same individuals were seen on different days and off South Africa during winter/spring 2013. the trip totals for these species should therefore be Seabirds were recorded opportunistically for treated with caution. 79 days at sea from a pelagic longline vessel Locations and dates of sightings of rare and operating off South Africa between 1 July and unusual seabird species are summarised in Table 1. 20 September 2013. Fishing operations were Fig. 1 shows the three primary fishing areas as well conducted on 62 days, with six days of no fishing due to bad weather. Most sightings were Figure 1. Map of route taken during rhe study, with made during hauling operations, when birds the South African exclusive economic zone (SA EEZ), congregated behind the vessel to scavenge for bait 200 m and 1,000 m isobars depicted. The three primary discards and offal. Additional sightings were made fishing areas are marked as a (c.400-650 km south-east while steaming between fishing grounds (11 days). of Durban), b (close offshore to Port Elizabeth) and c Fishing operations occurred in three distinct areas: (c.300-350 km south of Cape Agulhas). c.400-650 km south-east of Durban (17 days), Carte du trajet suivi pendant l’etude ; la zone close offshore to Port Elizabeth (15 days) and economique exclusive sud-africaine (SA EEZ) et les isobares de 200 m et 1.000 m sont egalement marquees. c.300-350 km south of Cape Agulhas (36 days) Les trois zones de peche principales sont indiquees (Fig. 1). comme a (environ 400-650 km au sud-est de Durban), Many sightings were confirmed after studying b (pas tres loin au large de Port Elizabeth) et c (environ photographs taken with a digital SLR camera 300-350 km au sud de Cape Agulhas). 164 - Bull ABC Vol 23 No 2 (2016) Rare seabird sightings off South Africa: Rollinson Table 1. Rare seabirds recorded off South Africa, July-September 2013. Tableau 1. Oiseaux de mer rares observes au large de I’Afrique du Sud en juillet-septembre 2013. MONTH TOTAL AREA July August September SE of Agulhas Port Durban Bank Elizabeth Wandering Albatross Diomedea exulans 59 73 10 142 31 98 13 'Tristan Albatross Diomedea dabbenena 2 3 5 5 - - - Northern Royal Albatross Diomedea sanfordi 4 29 9 42 39 3 - Southern Royal Albatross Diomedea epomophora 2 16 5 23 19 4 - 'Salvin’s Albatross Thalassarcbe salvini 1 1 1 - - - - 2Grey-headed Albatross Thalassarche chrysostoma 1 1 1 - - - - 'Sooty Albatross Phoebetria fusca 6 6 4 2 - - - 2Light-mantled Albatross Phoebetria palpebrata 2 2 2 - - - - 'Grey Petrel Procellaria cinerea 22 5 27 17 8 2 - Spectacled Petrel Procellaria conspicillata 3 3 3 - - - - 'Atlantic Petrel Pterodroma incerta 1 1 1 - - - - 'Blue Petrel Halobaena caerulea 2 2 4 2 2 - - 'Slender-billed Prion Pachyptila belcheri 1 1 1 - - - - Totals 100 135 26 261 55 178 28 1 Record accepted by the South African National Rarities Committee. 2 Recorded in international waters alone. Bull ABC Vol 23 No 2 (2016)-165 Rare seabird sightings off South Africa: Rollinson Table 2. Common seabirds recorded off South Africa. July-September 2013. Tableau 2. Oiseaux de mer communs observes au large de I'Afrique du Sud en juillet-septembre 2013. Abundance Area Shy Albatross Thalassarche cauta 1 steadi Seen daily in large numbers N\ Indian Yellow-nosed Albatross Thalassarche carteri Seen daily in large numbers All Atlantic Yellow-nosed Albatross Thalassarche chlororhynchos Seen daily in large numbers AIL except east coast Black-browed Albatross Thalassarche melanophris Seen daily but fewer than T. carteri All Southern Giant Petrel Macronectes giganteus Seen on most fishing days All Northern Giant Petrel M acronectes halli Seen on most fishing days All Pintado Petrel Daptlon capense Seen daily in large numbers All White-chinned Petrel Procellaria aequinoctialis Seen daily in large numbers All Sooty Shearwater Puffinus grlseus Seen on most days in low numbers All Flesh-footed Shearwater Puffinus carneipes Seen once Cape Agulhas Cory’s Shearwater Calonectris diomedea Seen on two occasions only Cape Agulhas Manx Shearwater Puffinus puffinus Seen once Cape Agulhas Great-winged Petrel Pterodroma macroptera Seen on most days in low numbers All Soft-plumaged Petrel Pterodroma mollis Seen on most days in low numbers All Antarctic Prion Pachyptila desolata Seen on most days in low numbers All Wilson’s Storm-petrel Oceanites oceanicus Seen daily in large numbers All Black-bellied Storm-petrel Fregetta tropica Seen in small numbers from September All Cape Gannet Morus capensis Seen in small numbers close to the coast All, except east coast Subantarctic Skua Catharacta antarctica Seen on most days in low numbers All Tern sp. Sterna sp. Small flocks seen occasionally All Kelp Gull Larus dominicanus Coastal areas only All Hartlaub’s Gull Larus hartlaubii Coastal areas only All, except east coast as the route taken by the vessel. Figs. 2-6 show the Figure 2. Sightings of Tristan Albatross Diomedea location of all rare bird records. Table 2 lists other dabbenena and Wandering Albatross D. exulans during the study. common species seen throughout the trip with an Observations de TAlbatros de Tristan Diomedea approximate estimation of abundance as well as dabbenena et TAlbatros hurleur D. exulans pendant area recorded. l’etude. Figure 3. Sightings of Southern Diomedea epomophora Wandering Albatross Diomedea exulans and Northern Royal Albatross D. sanfordi during Recorded on 48 of the 79 days at sea. Most the study. common off the Agulhas Bank (seen on 29 of Observations de TAlbatros royal Diomedea epomophora et 36 days; Figs. 2 & 7) and less frequent off Port TAlbatros de Sanford D. sanfordi pendant Tetude. Elizabeth (eight of 13 days) and south-east of Durban (11 of 17 days; Fig. 2). In total, 142 sightings were made, the majority off the Agulhas Crozet Islands, the others including Kerguelen, Bank (c.70%), with smaller numbers south-east Fleard, Macquarie and South Georgia (Shirihai of Durban and off Port Elizabeth (Table 1). As 2007). Post-breeding adults are known to many as ten individuals scavenged behind the travel from South Georgia to South African vessel while fishing off the Agulhas Bank. Largest waters in 6-10 days (Prince et al. 1998). I numbers were in July-August, with smaller photographed an immature with a green colour numbers in September (Table 1). All plumage ring r.400 km east of East London, which was stages were seen, from juveniles to almost all-white probably ringed on Bird Island, South Georgia, old adult males. as one of the 2011/12 cohort of fledglings Wandering Albatrosses breed on subantarctic (A. Wood pers. comm.). The species is scarce islands, the nearest being the Prince Edward and over the continental shell but is recorded more 166 - Bull ABC Vol 23 No 2 (2016) Rare seabird sightings off South Africa: Rollinson Tristan Albatross 40°0'S "iff 100 0 100 200 300 400 500 km • Wandering Albatross 20°0'E 25°0'E 30°0'E 35°0'E B Rare seabird sightings off South Africa: Rollinson Bull ABC Vol 23 No 2 (2016) - 167 regularly in oceanic waters, with most sightings Figure 4. Sightings of Salvin’s Thalassarche salvini. Grey-headed T. chrysostoma, Sooty Phoebetria fusca and off west and south coasts (Hockey et al. 2005). It Light-mantled Albatross P. palpebrata during the study. is observed with some frequency during pelagic Observations de l’Albatros de Salvin Thalassarche salvini, birdwatching trips operating from the Cape LAlbatros a tete grise T. chrysostoma, l’Albatros brun Peninsula, but numbers have declined in recent Phoebetria fusca et l’Albatros fuligineux P. palpebrata years (Hockey et al. 2005). Cyrus & Robson pendant P etude. (1980) recorded them as frequent visitors to the Figure 5. Sightings of Grey Procellaria cinerea, Spectacled KwaZulu-Natal coast during the atlas period P. conspicillata and Atlantic Petrels Pterodroma incerta (1970-80), but there have been very few records during the study. in recent years. Observations du Puffin gris Procellaria cinerea, du Petrel a lunettes P. conspicillata et du Petrel de Schlegel Tristan Albatross Diomedea dabbenena Pterodroma incerta pendant l’etude. Four confirmed sightings were made, all south of Cape Agulhas in oceanic waters (Fig. 2), although others might have been confused with Tristan Albatrosses regularly visit South African Wandering Albatrosses. The birds were separated waters, particularly non-breeding birds in April- from Wandering Albatrosses by the presence of October. Due to the difficulty of separating the a yellow alphanumeric ring (Fig. 7; all unringed species from Wandering Albatross at sea (Ryan D. exulans / dabbenena were presumed to be D. 2000), many are presumably overlooked. exulans). Ring numbers permitted ageing and sexing. All were adult males 19-35 years old, Northern Royal Albatross Diomedea sanfordi which had previously bred on Gough Island. Forty-two were recorded on 33 days, mainly off Two were failed breeders from 2013, one failed in the Agulhas Bank in August, with smaller numbers 2012, while the fourth successfully raised a chick off Port Elizabeth (Table 1; Fig. 7). None was seen on its last breeding attempt in 2009. south-east of Durban, which is unsurprising as the Tristan Albatross is Critically Endangered species has not been recorded from the KwaZulu- and endemic to the islands of Gough and Natal coast (Hockey et al. 2005). Most sightings Inaccessible, where it is thought to number were in water >1,000 m deep, although the species c.9,000 birds (Shirihai 2007). The population was also regularly seen in shallower water off has decreased in recent years, mostly due to Port Elizabeth in September (Fig. 3). Many were longline fishing and the introduction of mire juveniles / younger immatures, separated from to Gough Island (Wanless et al. 2009). The adults by the dark brown blotching on the lower species is considered uncommon in oceanic back and rump, as well as dark brown flecks on waters off the west coast and rare elsewhere in the crown and dark tail tip. the subregion (Hockey et al. 2005). Prior to this The species is thought to mostly occur off study, there were only eight confirmed records South Africa during passage from its wintering from southern African waters: live from the west grounds off South America to its breeding coast of South Africa and Namibia (Hockey grounds off New Zealand (Shirihai 20CC). My et al. 2005, Goren & Ryan 2010), one south sightings suggest that it occurs more regularly in of Cape Agulhas (B. Rose pers. comm.), one oceanic waters off South Africa than previously dead bird at Port Elizabeth (Ryan et al. 2001) thought. Northern Royal Albatrosses are regularly and one killed by a longline vessel off Durban recorded in southern African waters, mostly (Cooper 2011). Of these, only three previous over the continental shelf edge off western and sight records (of colour-banded individuals) southern coasts (Hockey et al. 2005). In recent exist, the other records all involved recoveries years they have been recorded in similar numbers of dead birds. Two additional sightings have to Wandering Albatross over the continental shelf, been made in South African waters since; one less frequently in oceanic waters (Hockey et al. south of Cape Point (pers. obs.) and another 2005). Virtually all southern African records are west of Cape Town (P. Ryan pers. comm.). in May-October, although there are records from However, as demonstrated by Reid et al. (2013), April and November as well. 168 - Bull ABC Vol 23 No 2 (2016) Rare seabird sightings off South Africa: Rollinson Rare seabird sightings off South Africa: Rollinson Bull ABC Vol 23 No 2 (2016) - 169 Southern Royal Albatross Diomedea epomophora mainly juveniles, wander north to 25°S (Hockey et Recorded on far fewer occasions than the previous al. 2005, Shirihai 2007). The species is recorded species (Fig. 3 & 7), with sightings on 20 days, within the southern African subregion in most mainly off the Agulhas Bank in August, with years, but not annually (Hockey et al. 2005). smaller numbers off Port Elizabeth in September Almost all records are of juveniles and most are (Table 1). from the Western Cape in May-October, with An estimated 8,200-8,600 pairs breed on the fewer from Eastern Cape and exceptionally from New Zealand islands of Campbell and Auckland, KwaZulu-Natal, Namibia and southern Angola and range at sea between 36°S and 63°S (Shirihai (Hockey et al. 2005). 2007). They forage mostly in New Zealand waters, although many also visit seas around Sooty Albatross Phoebetria fusca southern South America (Hockey et al. 2003). Only recorded in July, with four of the six birds The species is recorded less frequently than south-east of Durban (Table 1). Three of these Northern Royal Albatross within the subregion were seen in international waters (during hauling and prefers waters >1,000 m deep, beyond the operations), one in South African waters c.20 km continental shelf edge (Hockey et al. 2003). south-east of Durban (Fig. 9) and two together Southern Royal Albatross is recorded annually in off Port Elizabeth while steaming to the Agulhas southern African waters, mostly in June-October. Bank (Fig. 4). All were in oceanic waters >1,000 It appears to be restricted to the south coast of m deep. One showed patchy grey colouring on the South Africa with no known records further north mantle and head, which is typical of immatures off the west or east coasts (Hockey et al. 2005). (Shirihai 2007), whereas all of the others were thought to be adults, based on plumage coloration. Salvin’s Albatross Thalassarche salvini Most Sooty Albatrosses breed on Gough, A single immature was recorded off the Agulhas Tristan da Cunha and the Prince Edward Islands, Bank in August (Figs. 4 & 8). Most previous ranging throughout the Southern Ocean, preferring southern African records are of adults, but younger deeper waters north of the Antarctic Convergence birds may have been overlooked due to their Zone and south of 30°S (Shirihai 2007). It is similarity to juvenile / immature 'Shy’ Albatross from these principal breeding grounds that most T. cauta / steadi. southern African records are thought to originate. Most Salvin’s Albatrosses breed on New The species is suspected to occur year-round in Zealand’s subantarctic Snares and Bounty South African waters off south and south-west archipelagos. Birds either disperse west to the coasts (Hockey et al. 2005)- Occasionally birds south-west Indian Ocean or east to western South have been sighted further north off the east coast, America in winter (Shirihai 2007). Some seen in off KwaZulu-Natal, exceptionally as far north the Drake Passage and the south-western Atlantic as southern Mozambique. Most records closer Ocean may be the source of southern African inshore have been in winter, most probably records (Hockey et al. 2005). The species is a rare vagrants to the shelf-break and slope (Hockey et vagrant to the subregion, with confirmed sightings al. 2005). only since 2000, all from coastal Western Cape waters, with most in winter / spring (Hockey et al. Light-mantled Albatross Phoebetria palpebrata 2005, Davis 2006). Two sightings were made one week apart (thought to be the same individual) in international waters Grey-headed Albatross Thalassarche chrysostoma south-east of Durban (Fig. 4), during hauling A single juvenile was observed on two consecutive operations. Once the bird followed the vessel, days c.400 km south-east of Durban in mid July presumably waiting for offal discards (Fig. 10). while scavenging behind the vessel (Fig. 4). Light-mantled Albatrosses have a circumpolar Grey-headed Albatrosses breed throughout breeding distribution on subantarctic islands, the the circumpolar subantarctic islands, the nearest nearest being the Prince Edwards and Crozets. colonies being on the Prince Edward and Crozet They generally disperse south of 35°S, but wander groups. They are found most frequently over further north off the west coast of South America colder waters south of 40°S, although a few birds, (Onley & Schofield 2007). The species is a rare 170-Bull ABC Vol 23 No 2 (2016) Rare seabird sightings off South Africa: Rollinson Figure 6. Sightings of Blue Petrel Halobaena caerulea and Slender-billed Prion Pachyptila belcheri during the study. Observations du Prion bleu Halobaena caerulea et du Prion de Belcher Pachyptila belcheri pendant fetude. vagrant to southern African waters, with fewer waters, with most records from the south and west than ten records to date (Hockey et al. 2005). coasts in winter (Hockey et al. 2005). Records Most are from the Western Cape in winter, with from the east coast are even rarer, although there some stranded birds. Three are from the east coast: have been a few records off KwaZulu-Natal in two stranded birds from southern Mozambique recent years (Davis 2011, 2015). and the other from north-eastern KwaZulu-Natal (Hockey et al. 2005, Davis 2010). Spectacled Petrel Procellaria conspicillata Three singles were encountered off the Agulhas Grey Petrel Procellaria cinerea Bank in August (Fig. 5), where they scavenged for Of the 27 sightings, 22 were made in July; the bait discards and offal behind the vessel during majority were south-east of Durban (17 on six hauling operations. days; Figs. 5 & 11). As many as six were seen Spectacled Petrel is endemic as a breeder behind the vessel during hauling operations and to Inaccessible Island in the Tristan da Cunha the species was frequently observed diving for bait group, and is listed as Vulnerable with only discards and offal. Seven sightings of eight birds 14,400 breeding pairs (Ryan et al. 2001). It were made during the 36 days spent fishing off the ranges throughout the South Atlantic, mostly at Agulhas Bank (Fig. 5). 25-41°S (Hockey et al. 2005). It is an uncommon Grey Petrels are winter breeders, with the visitor to South African waters, mainly preferring nearest substantial breeding populations on oceanic waters up to the shelf edge, mostly off the Gough and the Prince Edward Islands; although west coast, with one record from KwaZulu-Natal they forage as far north as 25°S, they mainly (Hockey et al. 2005). Encountered year-round remain south of 35°S (Onley & Schofield 2007). on pelagic trips from the Cape Peninsula (http:// The species is considered rare in southern African www.zestforbirds.co.za). Rare seabird sightings off South Africa: Rollinson Bull ABC Vol 23 No 2 (2016) - 171 Figure 7. Diomedea albatrosses observed off South Africa, July—September 2013: (a) Wandering Albatross D. exulans, (b) Tristan Albatross D. dabbenena, (c) Southern Royal Albatross D. epomophora and (d) Northern Royal Albatross D. sanfordi (Dominic P. Rollinson) Albatros du genre Diomedea observes au large de PAfrique du Sud en juillet-septembre 2013 : (a) Albatros hurleur D. exulans, (b) Albatros de Tristan D. dabbenena, (c) Albatros royal D. epomophora et (d) Albatros de Sanford D. sanfordi (Dominic P. Rollinson) Atlantic Petrel Pterodroma incerta of Cape Town, in July-November, with just two One was briefly observed during rough weather records off the east coast, in August 1973 and in August when fishing operations had been September 1974 (Sinclair 1974, Cyrus & Robson suspended, r.230 km south of Cape Agulhas in 1980, Hockey et al. 2005). oceanic water (Fig. 3). Atlantic Petrel is endemic to the Tristan da Blue Petrel Halobaena caerulea Cunha group and Gough Island, chiefly dispersing Four were observed in southern African waters west to the central and south-western Atlantic (Figs. 6 & 12), three off the Agulhas Bank in (Shirihai 2007). Records from the Indian Ocean August (two in water >1,000 m deep) and one off are rare, but individuals have been recorded as far Port Elizabeth in September (also in water >1,000 as 104°E (Enticott 1991). The species is a rare m deep). Three of the four briefly followed the visitor to South African waters, mostly south-west vessel during hauling operations. 172-Bull ABC Vol 23 No 2 (2016) Rare seabird sightings off South Africa: Rollinson Figure 8. Immature Salvin’s Albatross Thalassarche salvini, south of Cape Agulhas, 16 August 2013 (Dominic P. Rollinson) Albatros de Salvin Thalassarche salvini immature, au sud de Cape Agulhas, 16 aout 2013 (Dominic P. Rollinson) Figures 9-10. Sooty Albatross Phoebetria fusca, 11 July 2013 and Light-mantled Albatross P. palpebrata, south¬ east of Durban, 20 July 2013 (Dominic P. Rollinson) Albatros brun Phoebetria fusca, 11 juillet 2013 et Albatros fuligineux P. palpebrata, au sud-est de Durban, 20 juillet 2013 (Dominic P. Rollinson) Blue Petrels have a circumpolar breeding distribution on Southern Ocean islands with the nearest populations nesting on the Prince Edwards and Crozets (Shirihai 2007). Young birds are thought to wander prior to breeding (Shirihai 2007), perhaps accounting for some of the vagrants to the subregion. Blue Petrels are rare winter visitors to southern African waters, but are prone to major irruptions, during which they can occur in large numbers (Ryan et al. 1989). The last major irruption was July-August 1984 when 76 were ‘wrecked’ on beaches across South Africa, coinciding with wrecks in Brazil and Australasia (Ryan et al. 1989). Observations at sea off the Northern and Western Cape prior to this African waters, with only one bird seen on Cape wreck indicated that the irruption preceded the Point pelagic trips (B. Rose pers. comm.); the wreck by some weeks (Ryan et al. 1989). Since few other sightings have been in deeper waters 1984 there have been very few sightings in South further offshore. Rare seabird sightings off South Africa: Rollinson Bull ABC Vol 23 No 2 (2016) - 173