This species is a member of the Blue-eyed Shag group. Some sources (IOC, HBW, Birlife International) use the English name, "Imperial Shag." The ones in front showing yellow caruncaruncles are post-breeding adults, which lack a crest and have a reduced white wing patch. Immatures lack the yellow skin in front of their eyes. Two types occur. Mainland birds have white cheeks while Falkland birds such as these have dark cheeks and a reduced white shoulder stripe. Historically the Falkland population was considered a separate species under the name "King Shag" while other authors consider it be just a color morph.
Taxonomy is complex. Here I follow Clements and IOC which split several former subspecies into full species. Under this arrangement, all the mainland South American birds are nominate, while P. a. albiventer is confined to the Falkland Islands. However other authors (HBW, Howard & Moore 4th) lump the Heard Island, Crozet, Macquarie, South Georgia, and Antarctic Shags as races. Canon PowerShot SX50 HS
References:
Gómez Laich, A. (2012). Imperial Cormorant (Phalacrocorax atriceps), version 1.0. In Neotropical Birds Online (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/nb.impcor1.01
Orta, J., Garcia, E.F.J., Christie, D.A., Jutglar, F. & Kirwan, G.M. (2018). 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. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/52649 on 4 May 2018).
Shirihai, H. (2002) A Complete Guide to Antarctic Wildlife. The Birds and Marine Mammals of the Antarctic Continent and the Southern Ocean. Princeton University Press: Princeton & Oxford.