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Population status of the Antarctic shag Phalacrocorax (atriceps) bransfieldensis

  • Michael Schrimpf (a1), Ron Naveen (a2) and Heather J. Lynch (a1) (a3)


Antarctic shags Phalacrocorax (atriceps) bransfieldensis are the southernmost cormorants in the world and assessment of their conservation status has been complicated by the logistical challenges of obtaining regular estimates of population size, as well as by taxonomic ambiguity of the blue-eyed shag complex. The available information on the taxonomy, distribution and population size of Antarctic shags are reviewed and a refined estimate of the global population is presented: 11 366 breeding pairs, plus an additional 1984 pairs of uncertain taxonomic status in the South Orkney Islands. This analysis suggests a possible spatial shift in the distribution of Antarctic shags similar to that reported for other Antarctic seabirds, which probably reflects a gradient in environmental changes along the western Antarctic Peninsula. This review should aid future conservation and management assessments.


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Barlow, E.J., Daunt, F., Wanless, S. & Reid, J.M. 2013. Estimating dispersal distributions at multiple scales: within-colony and among-colony dispersal rates, distances and directions in European shags Phalacrocorax aristotelis. Ibis, 10.1111/ibi.12060.
Bustnes, J.O., Anker-Nilssen, T., Erikstad, K.E., Lorentsen, S.H. & Systad, G.H. 2013. Changes in the Norwegian breeding population of European shag correlate with forage fish and climate. Marine Ecology Progress Series, 10.3354/meps10440.
Casanovas, P., Naveen, R., Forrest, S., Poncet, J. & Lynch, H.J. 2015. A comprehensive coastal seabird survey maps out the front lines of ecological change on the western Antarctic Peninsula. Polar Biology, 10.1007/s00300-015-1651-x.
Casaux, R. & Barrera-Oro, E. 2006. Shags in Antarctica: their feeding behaviour and ecological role in the marine food web. Antarctic Science, 10.1017/s0954102006000010.
Casaux, R. & Barrera-Oro, E. 2016. Linking population trends of Antarctic shag (Phalacrocorax bransfieldensis) and fish at Nelson Island, South Shetland Islands (Antarctica). Polar Biology, 10.1007/s00300-015-1850-5.
Che-Castaldo, C., Jenouvrier, S., Youngflesh, C., Shoemaker, K.T., Humphries, G., McDowall, P., Landrum, L., Holland, M.M., Li, Y., Ji, R. & Lynch, H.J. 2017. Pan-Antarctic analysis aggregating spatial estimates of Adélie penguin abundance reveals robust dynamics despite stochastic noise. Nature Communications, 10.1038/s41467-017-00890-0.
Cimino, M.A., Lynch, H.J., Saba, V.S. & Oliver, M.J. 2016. Projected asymmetric response of Adélie penguins to Antarctic climate change. Scientific Reports, 10.1038/srep28785.
Clements, J.F., Schulenberg, T.S., Iliff, M., Roberson, D., Fredericks, T.A., Sullivan, B.L. & Wood, C.L. 2016. The eBird/Clements checklist of birds of the world: v2016. Available at
Coria, N.R., Montalti, D., Rombola, E., Santos, M.M., Garcia Betoño, M.I. & Juares, M.A. 2011. Birds at Laurie Island, South Orkney Islands, Antarctica: breeding species and their distribution. Marine Ornithology, 39, 207213.
Gill, F. & Donsker, D. 2017. IOC world bird list (v 7.1). 10.14344/IOC.ML.7.1. Available at
Harris, C., Carr, R., Lorenz, K. & Jones, S. 2011. Important Bird Areas in Antarctica: Antarctic Peninsula, South Shetland Islands, South Orkney Islands – final report. Prepared for BirdLife International and the Polar Regions Unit of the UK Foreign & Commonwealth Office. Cambridge: Environmental Research & Assessment, 225 pp. Available at
Harris, C.M. 2006. Wildlife awareness manual: Antarctic Peninsula, South Shetland Islands, South Orkney Islands. Cambridge: Environmental Research & Assessment, 136 pp.
Harrison, P. 1985. Seabirds: an identification guide. Boston, MA: Houghton Mifflin Company, 448 pp.
Humphries, G.R.W., Naveen, R., Schwaller, M., Che-Castaldo, C., McDowall, P., Schrimpf, M. & Lynch, H.J. 2017. Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD): data and tools for dynamic management and decision support. Polar Record, 10.1017/s0032247417000055.
Johnsgard, P.A. 1993. Cormorants, darters, and pelicans of the world. Washington, DC: Smithsonian Institution Press, 445 pp.
Lynch, H.J., Naveen, R. & Fagan, W.F. 2008. Censuses of penguin, blue-eyed shag Phalacrocorax atriceps and southern giant petrel Macronectes giganteus populations on the Antarctic Peninsula, 2001–2007. Marine Ornithology, 36, 8397.
Lynch, H.J., Naveen, R. & Casanovas, P. 2013. Antarctic Site Inventory breeding bird survey data, 1994–2013. Ecology, 10.1890/13-1108.1.
Naveen, R., Forrest, S.C., Dagit, R.G., Blight, L.K., Trivelpiece, W.Z. & Trivelpiece, S.G. 2000. Censuses of penguin, blue-eyed shag, and southern giant petrel populations in the Antarctic Peninsula region, 1994–2000. Polar Record, 36, 323334.
Nur, N. & Sydeman, W.J. 1999. Survival, breeding probability and reproductive success in relation to population dynamics of Brandt’s cormorants Phalacrocorax penicillatus . Bird Study, 46, 92103.
Orta, J., Garcia, E.F.J., Christie, D.A., Jutglar, F. & Kirwan, G.M. 2017. Imperial shag (Phalacrocorax atriceps). In Del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E., eds. Handbook of the birds of the world alive. Barcelona: Lynx Edicions. Available at
Potts, G.R., Coulson, J.C. & Deans, I.R. 1980. Population-dynamics and breeding success of the shag, Phalacrocorax aristotelis, on the Farne Islands, Northumberland. Journal of Animal Ecology, 10.2307/4258.
Shirihai, H., Jarrett, B. & Cox, J. 2007. Complete guide to Antarctic wildlife, 2nd ed. London: A&C Black Publishers, 544 pp.
Shuford, W.D. & Spear, L.B. 1988. Surveys of breeding penguins and other seabirds in the South Shetland Islands, Antarctica, January–February 1987. Technical Memorandum NMFS-F/NEC-59. Woods Hole, MA: US Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Northeast Fisheries Center, 27 pp.
Sibley, C.G. & Monroe, B.L. 1990. Distribution and taxonomy of birds of the world. New Haven, CT: Yale University Press, 1111 pp.
Siegel-Causey, D. 1988. Phylogeny of the Phalacrocoracidae. Condor, 90, 885905.
Watson, E. 1975. Birds of the Antarctic and sub-Antarctic. Washington, DC: American Geophysical Union, 350 pp.
Woehler, E.J., Blight, L. & Bullock, I. 2010. Ornithological observations at Eckener Point, Antarctic Peninsula. Polar Record, 46, 279281.


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Population status of the Antarctic shag Phalacrocorax (atriceps) bransfieldensis

  • Michael Schrimpf (a1), Ron Naveen (a2) and Heather J. Lynch (a1) (a3)


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