Sooty Albatross on Amsterdam Island, photograph by Dominique Filippi

Yves Cherel and Colette Trouvé (Centre d’Etudes Biologiques de Chizé, Villiers-en-Bois, France) have published in the journal Deep–Sea Research I on the squid diets of Phoebetria albatrosses on two French islands in the southern Indian Ocean.

The paper’s abstract follows:

Using a total of ~7000 accumulated beaks sorted from 92 food samples, the cephalopod diet of sooty albatross Phoebetria fusca was determined for the first time at the subtropical Amsterdam Island (3898 beaks from 53 food samples), and it was compared with prey eaten at the subantarctic Crozet Islands (3085 beaks from 39 samples).  At Amsterdam Island, sooty albatross fed on 42 cephalopod taxa that included the dominant Histioteuthis atlantica (34.7% by number of beaks) and juvenile Ommastrephes cylindraceus/Todarodes filippovae (10.1%). They preyed primarily upon cephalopods that have a wide latitudinal distribution (55.1%), with subtropical species ranking second (25.8%), and Southern Ocean endemics third (19.1%). By contrast, birds from Crozet Islands fed primarily on Southern Ocean endemics (80.7%), followed by subtropical species (14.8%), and taxa with a wide distribution (4.5%).  There, the main prey were adult Histioteuthis eltaninae (24.6%), Batoteuthis skolops (27.2%) and Galiteuthis glacialis (16.2%).  Sympatric sooty and light-mantled sooty P. palpebrata albatrosses from Crozet Islands segregated by feeding on different prey indicating different foraging grounds north and south of the archipelago, respectively.  Light-mantled sooty albatross fed almost exclusively on Southern Ocean endemics (98.2%), such as G. glacialis (44.4%), Psychroteuthis glacialis (21.4%), H. eltaninae (13.4%) and Moroteuthopsis longimana (10.2%).  Including cephalopod prey of sooty albatross to the previous investigations on teuthofauna from the southern Indian Ocean added southern subtropical species to Southern Ocean taxa.  Overall, teuthofauna of this vast oceanic zone hosts at least 71 cephalopod species, including two bathyteuthids, 56 oegopsids, two sepiolids, three cirrate and seven incirrate octopods, and the vampyroteuthid Vampyroteuthis infernalis.\

Reference:

Cherel, Y & Trouvé, C. 2024.  .Comparison of cephalopods eaten by sooty albatross Phoebetria fusca breeding in subtropical and subantarctic waters, and teuthofauna of the southern Indian Ocean.  Deep–Sea Research I 206 104262.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 14 April 2025

Personal note:  It has been three decades since I published (with the late Norbert Klages) on the squid diet of Phoebetria albatrosses!

Cooper, J. & Klages, N.T.W. 1995.  The diets and dietary segregation of sooty albatrosses (Phoebetria spp.) at subantarctic Marion Island.  Antarctic Science 7: 15-23.

(A) Map of Gough Island and relevant features, with an inset map of the 2 study areas (Gonydale and Hummocks) that were cloud-free in the satellite image.  (B) Satellite image (33 cm resolution downsampled to 30 cm resolution) showing GPS coordinates of Tristan albatross nests from ground surveys in 2018, and nests and presumed non-breeders observed in imagery. Three random examples from the satellite image shows an individual nesting Tristan albatross as light pixels in the centre of the panel (from the publication)

Marie Attard (British Antarctic Survey, Cambridge, UK) and colleagues have published in access in the journal Endangered Species Research on attempting to monitor Critically Endangered Tristan Albatross Diomedea dabbenena using satellite imagery.

The paper’s abstract follows:

“The Tristan albatross Diomedea dabbenena is a Critically Endangered species that breeds exclusively on remote islands in the South Atlantic Ocean. Although the population continues to decline, regular on-the-ground monitoring of Tristan albatross populations is logistically challenging and costly. If this monitoring is reduced in the future, then alternative methods would be necessary to track long-term population trends.  Here, we assessed the viability of using 31 cm resolution satellite imagery to count Tristan albatrosses during the breeding season on Gough Island.  Counts of birds in a satellite image by 2 wildlife remote-sensing specialists were compared with GPS coordinates of active nests recorded in the field.  Birds were detected at 103 (67.8%) of the 152 active nests in the cloud-free regions of the satellite image.   Acquiring suitable imagery is challenging because upland nesting sites are prone to low-lying orographic cloud, with only 1 cloud-free image obtained across 8 seasons of archived and 1 yr of tasked imagery. Our research demonstrates that due to incomplete detection, and the limited availability of suitable imagery resulting from persistent cloud cover over the island, Tristan albatrosses cannot be reliably counted or monitored with available satellite imagery.  Differences in detection probability were not explained by nest attributes or bird plumage colouration. More commercial satellites in orbit may improve chances of obtaining cloud-free imagery across the island in the future, but until then, on-the-ground monitoring is required if we are to obtain accurate population counts and for the UK to meet its commitments to monitor this species.”

With thanks to Richard Phillips, Britih Antarctic Survey.

Reference:

Attard, M.R.G., Phillips, R.A., Oppel, S., Bowler, E. & Fretwell, P.T. 2025.  Feasibility of using very high-resolution satellite imagery to monitor Tristan albatrosses Diomedea dabbenena on Gough Island.  Endangered Species Research 56: 187-199.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 11 April 2025

Great Shearwaters at sea, illustration from the Royal Society for the Protection of Birds

Ewan Wakefield (Department of Geography, Durham University, UK) and colleagues have published in the open access journal Marine Ornithology on plumage variation in Great Shearwaters Ardenna gravis.

The paper’s abstract follows:

“Most petrels (family Procellariidae) exhibit little or no obvious variation in plumage with age or sex, either because plumage performs no sexual function or does so in a way poorly perceptible to humans. This limits the inferences that can be made from visual observations of petrels at sea.  However, it has been suggested that nape coloration of Great Shearwaters Ardenna gravis whitens with age.  Here we test this supposition using observations of known-age-class individuals. We necropsied birds bycaught around Gough Island, a major breeding colony in the South Atlantic Ocean, and in Massachusetts Bay, a wintering area off the northeastern coast of the USA, to determine sex and classify nape coloration.  In addition, we classified the nape coloration of adults and fledglings photographed in colonies on Gough Island and Inaccessible Island in the South Atlantic.  Across birds (n = 328), ratios of light:intermediate:dark napes did not differ significantly between age classes, and the accuracy of age classification based on putative nape variation was only 52%.  Nape coloration did, however, vary systematically with sex and location: in Massachusetts Bay, light napes were more prevalent in adult females.  Off Gough Island, where only adults were sampled, this disparity did not occur.  We conclude that while nape coloration may vary due to feather wear, it is not a reliable indicator of age.  Rather, it may perform a sexual function, possibly mediating mate choice.  Further study of plumage variation and behavior at the colony would be required to test this hypothesis.”

Reference:

Wakefield, E.D., Robuck, A. R., Powers, K.D., Ronconi, R.A., Ryan, P.G., & Wiley, D.N. 2025.  Nape coloration varies with sex, not age, among Great Shearwaters Ardenna gravis.  Marine Ornithology 53: 151-158.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 10 April 2025

Amsterdam Island before the fire, photograph by Thierry Micol

ACAP Latest News has previously reported on the January wildfire that caused the evacuation of the personnel manning France’s Amsterdam Island in the southern Indian Ocean.  More information comes from a 15.34-minute video narrated in French and entitled "What will remain of this unique island?".

“This giant fire has been gaining ground for several hours.  And we're on this French base, without a fire station, on one of the most isolated islands in the world...  Lucas is going to immerse us in this true story today.  That of Amsterdam Island, a French island isolated from the rest of the world, home to a handful of people and a unique flora and fauna... all threatened by a giant fire." [Google Translate]

With thanks to Maëlle Connan.

John Cooper, Emeritus Information Officer, Agreement on the Conservation of Albatrosses and Petrels, 09 April 2025