PHALACROCORACIDAE
Cormorants
Forty-plus species in one to eight genera, depending on taxonomic opinion. In this thread I have used forty-two species in eight genera. Twenty-nine of those species are represented in the Zoochat galleries, encompassing all eight genera.
There are a variety of opinions on how many genera there are in Phalacrocoracidae, and which species belong in which genera. The uncertainties have been compounded by how similar all species are in their general morphology.
Traditionally, all species have been placed in the genus
Phalacrocorax. This is the "safest" option as there is quite a bit of dispute over the divisions of genera, but it is also quite clear that this is not an accurate position to take.
In New Zealand, which is home to a third of the species, three genera are normally used.
Phalacrocorax is used for the "typical" cormorants (including the small species otherwise placed in
Microcarbo), while
Stictocarbo is used for the two species of spotted shags, and
Leucocarbo is used for the king shags.
The HBW recognises seven genera (listed here using their order):
Microcarbo (four species);
Poikilocarbo (one species, the Red-legged Cormorant);
Leucocarbo (ten species);
Nannopterum (three species);
Urile (four species);
Gulosus (one species, the European Shag); and
Phalacrocorax (eleven species, including the New Zealand
Stictocarbo species).
Although having seven genera might seem excessive the arrangement of HBW follows a 2014 paper ("Classification of the cormorants of the world" by Kennedy and Spencer) which suggests that these lineages are indeed completely distinct, and have been evolving separately since at least the Miocene. The paper is pretty heavy because it is about genetics, but it makes a good case.
I have followed the Kennedy and Spencer genera here, although retaining
Stictocarbo separately simply because this is a commonly-accepted genus (for the sake of accuracy, please note that in their 2014 study the
Stictocarbo species fell well within the genus
Phalacrocorax). In the following accounts the genera are placed alphabetically (rather than systematically), with the species also arranged alphabetically under each genus.
Cormorants are medium-sized aquatic birds with an upright posture, long neck, elongated hook-tipped bill, and short legs. If penguins could still fly, they would look similar to cormorants. With the exception of the Flightless Cormorant
Nannopterum harrisi from the Galapagos Islands, all extant species are good fliers although they are generally restricted to coastal areas (rather than being pelagic birds). Species tend to be either marine or freshwater, with only a few species using both environments equally. The family occurs worldwide from the tropics to the subpolar regions. Most species are monomorphic (i.e. male and female birds have the same plumage), and in most species the young birds have a different plumage to the adults. During breeding the soft colours (e.g. facial skin) may change, and some species may also change plumage colour and/or grow crests.
The photo below, taken by
@Chlidonias at Te Papa (New Zealand), depicts a museum display of eight species of New Zealand cormorants showing how similar all species are in general appearance (the description on the photo identifies the species).
Display of some of the New Zealand cormorant species - ZooChat
A note on common names:
While "cormorant" is used for the family as a whole, and can be used for any individual species, many species are also (or instead) called "shags". There is no real distinction between these two names, and it mostly comes down to local usage - e.g. in New Zealand all species are called shags, even the Great Cormorant
Phalacrocorax carbo is just called the Black Shag in New Zealand.
The "original" two phalacrocoracids were named in England as "the Cormorant" (i.e.
P. carbo) and "the Shag" (i.e.
P. aristotelis). This influenced the naming of other species around the world, with one distinction being that primarily-freshwater species ended up being called cormorants and primarily-marine species being called shags. There were even (now outdated) taxonomic divisions based on this idea. Crested species also tended to be called shags rather than cormorants, as the European Shag has a crest (hence the name).
SPECIES LIST:
Listed aphabetically by genus, and the species within each genus likewise listed alphabetically. The species marked with an asterisk are depicted within this thread.
Gulosus
*European or Common Shag
Gulosus aristotelis
Leucocarbo
*Imperial or Blue-eyed Shag
Leucocarbo atriceps (including the White-bellied Shag
Leucocarbo albiventer as a subspecies)
Antarctic Shag
Leucocarbo bransfieldensis (treated as a subspecies of
L. atriceps in HBW)
*Guanay Cormorant
Leucocarbo bougainvillii
Campbell Island Shag
Leucocarbo campbelli
*New Zealand King Shag
Leucocarbo carunculatus
*Otago Shag
Leucocarbo chalconotus (formerly "Stewart Island Shag
L. chalconotus", but recently split into Otago Shag
L. chalconotus and Foveaux Shag
L. stewarti)
Auckland Island Shag
Leucocarbo colensoi
South Georgia Shag
Leucocarbo georgianus (treated as a subspecies of
L. atriceps in HBW)
Rock Shag
Leucocarbo magellanicus
Crozet Island Shag
Leucocarbo melanogenis (treated as a subspecies of
L. atriceps in HBW)
Heard Island Shag
Leucocarbo nivalis (treated as a subspecies of
L. atriceps in HBW)
*Chatham Island Shag
Leucocarbo onslowi
Macquarie Island Shag
Leucocarbo purpurascens (treated as a subspecies of
L. atriceps in HBW)
Bounty Island Shag
Leucocarbo ranfurlyi
*Foveaux Shag
Leucocarbo stewarti (included under "Stewart Island Shag
L. chalconotus" in HBW because this split is a recent one)
Kerguelen Shag
Leucocarbo verrucosus
Microcarbo
*Long-tailed or Reed Cormorant
Microcarbo africanus
*Crowned Cormorant
Microcarbo coronatus
*Little Pied Cormorant
Microcarbo melanoleucos
*Little Cormorant
Microcarbo niger
*Pigmy Cormorant
Microcarbo pygmaeus
Nannopterum
*Double-crested Cormorant
Nannopterum auritus
*Neotropical or Olivaceous Cormorant
Nannopterum brasilianus (syn.
N. olivaceus)
Flightless or Galapagos Cormorant
Nannopterum harrisi
Phalacrocrax
*Cape Cormorant
Phalacrocorax capensis
*Temminck's or Japanese Cormorant
Phalacrocorax capillatus
*Great Cormorant
Phalacrocorax carbo
*Black-faced Cormorant
Phalacrocorax fuscescens
*Indian Cormorant
Phalacrocorax fuscicollis
*White-breasted Cormorant
Phalacrocorax lucidus (treated as a subspecies of
P. carbo in HBW)
*Wahlberg's or Bank Cormorant
Phalacrocorax neglectus
*Socotra Cormorant
Phalacrocorax nigrogularis
*Little Black Cormorant
Phalacrocorax sulcirostris
*Pied Cormorant
Phalacrocorax varius
Poikilocarbo
*Red-legged Cormorant
Poikilocarbo gaimardi
Stictocarbo
*Pitt Island Shag
Stictocarbo featherstoni
*Spotted Shag
Stictocarbo punctatus
Urile
*Pelagic or Baird's Cormorant
Urile pelagicus
*Brandt's Cormorant
Urile penicillatus
Spectacled Cormorant
Urile perspicillatus (extinct c. 1850)
Red-faced Cormorant
Urile urile
