Cormorants

Although most Cormorants and Shags are (still) placed in Phalacrocorax (Nelson, 2005) the group as whole can be divided into two subgroups: the Cormorants and the Shags and these in their turn are divided into two ore more genera and groups by various authors. This division is based on ecological, behavioral and physiological characteristics (Johnsgard, 1993) and more recently on the studies of Siegel-Causey (1988) and Kennedey et al. (2000). More about taxonomy
Cormorants can be found on inland and coastal waters and vary very much in size, from the small Long-tailed to the very large, but extinct Pallas’ Cormorant.
This page treats the ‘true’ cormorants of the genera Phalacrocorax and Microcarbo.

Osteology

All Cormorants, Shags and Darters have a small bone at the back of the skull, the occipital style. This bone is flexibly attached to the skull and is supposed to have a function for the grasping ability of these birds. The ramphotecal coating of the  bills of the cormorants are divided in plates, very much like those of the tubenoses, without visible nostrils. See also the osteology page.

Macrocormorants

Genus Phalacrocorax

Subgenus Phalacorocorax

All rather large Cormorants, only Cape Cormorant is smaller. Kennedy et al. (2000) found genetic evidence that this species belongs to this subgenus.

  • Great Cormorant Phalacrocorax carbo. Six to seven subspecies: 
    • Atlantic Cormorant P. c. carbo. Northern Europe to North African coast and eastern North American coast and Greenland.
    • Eurasian Cormorant P. c. sinensis. Netherlands, northern Central Europe to China.
    • P. c. hanedae. Japan.
    • P. c. maroccanus. Coastal north-western Africa.
    • White-breasted Cormorant P. c. lucidus. Cape Verde Is., South Africa, inland lakes in Central Africa.
    • Black Cormorant P. c. novaehollandiae. Australia, Tasmania,
    • Black Cormorant P. c. steadi (sometimes considered separate subspecies). New Zealand and the Chatham Is.
  • Japanese Cormorant Phalacrocorax capillatus. Japan, Korea, coastal China.
  • Cape Shag or Cape Cormorant Phalacrocorax capensis. Endemic to coast south-western Africa.

Great (Eurasian) Cormorant
Phlalacrocorax carbo carbo
IJsselmeer, The Netherlands
Culmen: 78.3 mm,
Total: 153,5 mm (ex occ. style)
Adult male
More about carbo & sinensis

Cape Shag
Phalacrocorax capensis
South Africa
Culmen: ca 54 mm;
Total: 116 mm (occipital style missing)
Unsexed adult.

Mesocormorants

Genus Phalacrocorax

Rather large to rather small Cormorants. Five species:

  • Double-crested Cormorant Phalacrocorax auritus. North America. Five subspecies: 
    • White-crested Cormorant P a. cincinatus. Aleutians and Alaska, coastal
    • Farallon Cormorant P. a. albociliatus. British Columbia down to Baja California, coastal
    • Northern Double-crested Cormorant P. a. auritus. Alberta to Central USA and East Coast from Labrador to Massachusetts
    • Florida Cormorant P. a. floridanus. North Carolina, Florida to Texas, Cuba and probably Bahamas
    • P. a. heuretus. Resident on San Salvador I., Bahamas.
  • Neotropic (Olivaceous) Cormorant Phalacrocorax brasilianus. Two subspecies
    • P. b. mexicanus. Southern USA to Nicaragua and some Caribbean islands.
    • P. b. brasilianus. Costa Rica down to Terra de Fuego, inland and coastal.
  • Galapagos Cormorant Phalacrocorax harrisi, Endemic to Galapagos Is.
  • Pied Cormorant Phalacrocorax varius. Two subspecies: 
    • P. v. hypoleucos. Resident inland and coastal Australia, sometimes Tasmania.
    • P. v. varius. coastal New Zealand
  • Little Black Cormorant Phlacrocorax sulcirostris. Java and New Guinea to Australia and New Zealand
  • Indian Cormorant Phalacrocorax fuscicollis. India to Indochina and Sri Lanka, inland and coastal.
  • Bank Cormorant Phalacrocorax neglectus. Resident of Namibia to the Cape of South Africa, coastal.
  • Black-faced Cormorant Phalacrocorax fuscescens. South Australian Coast

Double-crested (Farallon) Cormorant
Phalacrocorax auritus albociliata

Florence, OR, USA
Culmen: 63.8,
Total: 134,6 mm (ex occ. style)
Unsexed adult

Pied Cormorant
Phlalacrocorax varius varius

Oakura, North Island, New Zealand
Culmen: 66.3 mm,
Total : 138.9 mm (ex occ. style)
Unsexed adult

Black-faced Cormorant
Phalacrocorax fuscescens

Kingscote, Australia
Culmen: ca. 51 mm,
Total: 119.4 mm (ex.occ. style) Unsexed adult

Neotropic (Olivaceous) Cormorant
Phalacrocorax brasilianus brasilianus

Salango, Equador
Culmen: 53. mm,
Total: 111,6 mm (ex. occ. style)
unsexed adult

Microcormorants

Genus Microcarbo

A group of small Cormorants from Africa, Indo-Malaysia and Australasia.
  • Little Pied Cormorant Microcarbo melanoleucos. Three subspecies:
    • M. m. melanoleucos. Resident Lesser Sundas and Sulawesi, New Guinea, Solomons, New Caledonia and Australia.
    • M. m. brevicauda. Endemic to Renell Island (Solomons)
    • M. m. brevirostris. Endemic to New Zealand, inland and coastal
  • Long-tailed or Reed Cormorant Microcarbo africanus. Two subspecies: 
    • M. a. africanus. Resident interior Africa
    • M. a. pictilis. Resident interior Madagascar, possibly separate species
  • Crowned Cormorant Microcarbo coronatus, sometimes considered a subspecies of m. africanus; coastlines of Namibia and South Africa
  • Pygmy Cormorant Microcarbo pygmaeus. South-east Europe, Turkey, Iraq, Iran and Black, Caspian and Aral Sea area.
  • Little or Javanese Cormorant Microcarbo niger, sometimes considered to be a subspecies of M. pygmaeus, India and South-east Asia, Sumatra and Java, inland and coastal.

Long-tailed cormorant
Microcarbo africanus pictilis

Lac Itasy, Madagascar
Culmen: 33.8 mm,
Total: 84,9 mm (ex. occ. style)

References