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estimate of 5000 pairs on Gough is very . However, counts of much a thumb suck. We know there are lots Sooties on sea cliffs depend greatly on the of Sooties at the island and on a calm day extent to which researchers are prepared it is not unusual to see hundreds spiralling to descend to the very edge of the cliffs together around the island’s peaks. But the to peer down. The population estimate island is so rugged that no attempt has been for Prince Edward Island almost doubled made to estimate their numbers with any when a more adventurous observer con- accuracy. Population trends at Gough are ducted the count in 2008! based on counts at 16 sites close to the is- Sporadic counts on Marion Island in the land’s weather station where 220–240 pairs late 1970s and during the 1980s suggested breed each year. The most recent analysis an annual breeding population of almost of these counts (Cuthbert et al. 2014) sug- 2000 pairs. Counts from 1996 onwards gests that the population has remained showed numbers decreasing to perhaps stable over the past decade or so, but only 1400 pairs by 2008 (Ryan et al. 2009). How- a tiny fraction of the island population is ever, a new paper analysing counts until monitored. 2014 shows that this decrease has been re- At the Crozet Archipelago, only the versed in the past few years, with the popu- population on Île de la Possession is count- lation increasing on average at four per cent ed regularly; estimates for the four other per year since 2006 (Schoombie et al. 2016). islands in the group date back to the 1970s It was recommended that a dedicated and 1980s. The numbers breeding at Posses- count be made specifically for Sooty Alba- sion decreased from some 300 pairs in 1980 trosses in mid-October, when most pairs to about 70 pairs in 2005, but have since re- have just laid. Traditionally, counts have Light-mantled breeding success at covered to more than 110 pairs. However, if been conducted in late November, by which Marion Island is very low and its numbers the numbers breeding at the other Crozet time some pairs have already failed. In have halved in the past decade. islands have followed the same trend, the 2015, the count yielded at least 2250 pairs total population for this island group may on Marion, the highest ever count for this hat about Light-mantled Alba-

peter ryan (3) now be less than 1000 pairs. island. Caution is needed when interpret- trosses? Ryan et al. (2009) found see-saw On ’s Prince Edward Is- ing annual counts, however, because Sooty that their numbers increased Contrasting population trends in lands most Sooty Albatrosses breed on Albatrosses typically take a year off after atW Marion Island between 1996 and 2008, relatively low sea cliffs, where they are having bred successfully. As a result, the mirroring a similar trend at Île de la Pos- he two Phoebetria albatrosses, more sparsely populated open ocean. The Albatross – breeds a little earlier than its easier to count than on the much larger numbers breeding in a given year depend session in the Crozets. But in recent years Sooty and Light-mantled, feature is the more likely to be southern counterpart. sea cliffs and inland valleys at Gough and in part on success in the preceding year. A their numbers have decreased rapidly from highly on many birders’ wishlists. encountered off southern Africa because Currently, the Light-mantled Albatross poor breeding year results in a bumper in- about 500 pairs in 2009 to 250 pairs in TWith their long, thin wings and wedge- it tends to forage farther north than its is listed as Near-Threatened globally. By cubator count the following year, whereas 2014 (Schoombie et al. 2016). This shaped tails, the look somewhat like slightly larger, paler cousin. comparison, the Sooty Albatross is listed a good breeding year will tend to reduce is harder to count accurately at Marion be- sea-going Bearded Vultures. And indeed The Light-mantled Albatross is the as Endangered because of apparent popu- breeding numbers. However, there was cause most of the population breeds at very they spend much time soaring along cliffs more abundant species globally, with lation decreases at three major breeding nothing to suggest that breeding success in low densities on inland cliffs, where they at their breeding islands. They are the least some 20 000 pairs breeding each year at sites: (which is home to per- 2014‒15 was unusually low. are difficult to locate. However, we might agile of the albatrosses on land, always sub-Antarctic islands between 46°S and haps 5000 pairs), the The most recent estimate for neigh- expect their population to dwindle as rapid breeding on steep slopes where they can 54°S right around the , (2500 pairs) and the Crozets (2200 pairs). bouring Prince Edward Island dates back climate warming in the region favours the alight and take off right at their nest site. from South Georgia through the Indian The main threat to the species is by-catch to 2008, when 1500 pairs were reckoned more northerly Sooty Albatross. Breeding But these high-speed gliders are primarily Ocean islands to the New Zealand sub- on fishing gear, especially long-lines. Sooty to be breeding there. Ignoring the pos- success of Light-mantled Albatrosses on designed to soar over the restless surface of Antarctic. By comparison, the 13 000 or Albatrosses are at greater risk because their sibility that this population might also Marion Island has been abysmal in recent the Southern Ocean. Boasting the highest so pairs of Sooty Albatrosses breed farther more northerly foraging range overlaps have increased over the past few years, years, suggesting that this species is strug- aspect ratios of any , they are at home north at islands in the South Atlantic and more extensively with tuna fisheries. this gives a total South African popula- gling at the northern edge of its range as the in the Roaring Forties and Furious Fifties. south-west , between 37°S tion of 3750 pairs, at least one quarter Southern Ocean warms. Part of their allure for southern African and 47°S (although a few pairs breed at owever, the inference of a popu- of the global count. Coupled with the PETER RYAN birders comes from their rarity – they are Kerguelen at 49°S). The two species breed lation decrease is complicated apparently stable population at Gough almost never seen on small-boat pelagic together at South Africa’s Prince Edward by the species’ biennial breeding Island, the recent findings from Marion References trips because they eschew the crowded Islands, 1750 kilometres south-east of Hcycle and the difficulty of counting these Island suggest that the threat status of the Cuthbert et al. 2014. Antarctic Science 26: continental shelf edge in favour of the Port Elizabeth, and the French Crozet albatrosses. With their dark plumage, low Sooty Albatross should be down-listed 163‒171. Archipelago, 1000 kilometres farther east. breeding densities and cliff-nesting hab- from Endangered. However, the rapid Ryan et al. 2009. African Journal of Marine above Sooty Albatrosses are hard to count, As is often the case where a latitudinally its, Sooty Albatrosses are hard to count, Sooty Albatross chicks on their nests on proliferation of mouse attacks on Sooty Science 31: 409‒417. especially on Gough Island where they breed segregated species-pair overlaps, the more especially on islands (like Gough) that Marion Island. Accurate counts are possible Albatross chicks on Marion Island over Schoombie et al. 2016. African Journal of on rocky outcrops throughout the island. northerly species – in this case the Sooty have large, inaccessible cliffs. In truth, the along most of the island’s low cliffs. the past two years is cause for concern. Marine Science 38: 119‒127.

10 african birdlife july/august 2016 news & views 11