Little black cormorant (Phalacrocorax sulcirostris)

Little black cormorant fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Little black cormorant description

A small, slender and elegant water bird ^{(3) (4) (5)}, the little black cormorant (Phalacrocorax sulcirostris) has black or brownish-black plumage ^{(3) (4) (5) (6)}, which is covered in a dull, green gloss ^{(4) (5) (6) (7)}. The feathers of the back and wings are grey ^{(6) (7)}, and are accentuated by dark edges ^{(4) (5) (6) (7)}, giving the little black cormorant a scalloped appearance ^{(4) (5) (7)}.

During the breeding season, breeding adults differ from non-breeding individuals in having narrow white markings over the eyes and on the head ^{(2) (4) (7)}, and a more bronze-washed sheen ⁽⁴⁾. Non-breeding adults are generally duller ⁽²⁾. There is no visible difference in plumage colouration between the sexes ⁽⁷⁾, and juveniles are similar in appearance to the adults but tend to be both duller and browner ^{(2) (4) (5)}.

The little black cormorant has dark facial skin ^{(3) (4) (5)}, except for the skin around the eyes and the patch joining the lower part of the beak to the neck which is strongly tinged with blue ⁽⁷⁾. This species has a long, thin, lead-grey bill ^{(3) (4) (5)}, green eyes and black feet ^{(5) (7)}.

Also known as

little black shag.

Synonyms

Carbo sulcirostris.

Size

Length: 55 - 65 cm ^{(2) (3)}

Wingspan: 95 - 105 cm ^{(2) (3)}

Weight

520 - 1,210 g ^{(2) (3)}

Little black cormorant biology

Often seen perched on branches overhanging the water or on rocks at the water’s edge ^{(2) (4) (7)}, the little black cormorant is a gregarious species ⁽⁵⁾, forming small to large flocks ^{(3) (4)}. These flocks feed as a coordinated group and can be observed flying low over the water in a ‘V’ formation ⁽⁵⁾, before coming in to roost on natural perches or on stumps, posts and other artificial structures ⁽³⁾.

The diet of the little black cormorant comprises mostly fish ^{(2) (3) (7)}, including Australian smelt (Retropinna semoni) and large quantities of introduced fish species such as crucian carp (Carassius carassius) and redfin or European perch (Perca fluviatilis) ^{(2) (3) (11)}. The little black cormorant also feeds on molluscs ⁽¹¹⁾, insects ^{(3) (11)}, crustaceans ^{(2) (3) (11)}, including freshwater crayfish, yabbies and shrimps ⁽¹¹⁾, and sometimes on frogs and newts ⁽⁷⁾.

Frequently fishing cooperatively in a dense, coordinated flock of up to 1,000 birds or more ^{(2) (4)}, the little black cormorant feeds mainly by pursuit-diving ⁽²⁾. Foraging generally occurs in relatively shallow areas, and the little black cormorant is known to occasionally feed within vegetated water around the edges of lakes or reedy swamps ⁽³⁾.

Breeding in the little black cormorant can occur all year round ⁽²⁾, and is dependent upon the season, water conditions and food availability ^{(2) (3)}. In northern Australia, breeding generally takes place between April and August ⁽²⁾, whereas in southern locations it tends to occur in spring to autumn ⁽³⁾. In New Zealand, the little black cormorant is known to breed between November and April ⁽⁵⁾.

A colonially nesting species ^{(2) (3)}, the little black cormorant typically forms small breeding colonies of just a few pairs, but these can number up to 1,000 ⁽²⁾. This species often nests in the company of other water birds, including other cormorant species, darters, herons, spoonbills, egrets and ibises. The little black cormorant’s nest consists of a platform of sticks, leaves and dry reeds which is lined with leaves, feathers, grass and bark ^{(2) (3)}. The nest is constructed in high forks within large trees, often over or near water ^{(2) (3) (4)}.

A typical little black cormorant clutch contains three or four eggs, although this species has been known to lay up to six ⁽²⁾. There is no information available on the period of incubation, period from hatching to maturity, or the age at which the little black cormorant first breeds. However, the period until fledging is thought to be more than seven weeks ⁽³⁾.

Little black cormorant range

The little black cormorant is widespread throughout Australia ^{(2) (3) (4) (8) (9) (10)}, including Tasmania ^{(2) (9)}. While its distribution is considered to be limited in Australasia ⁽³⁾, this species also occurs in New Zealand, Indonesia, New Guinea ^{(2) (4) (8) (9) (10)} and Timor-Leste ⁽¹⁰⁾. In New Zealand, the little black cormorant is mostly found on the North Island ⁽²⁾, being considered rare on the South Island ⁽⁵⁾.

In the Malay Archipelago, the little black cormorant is known to be found in the lowlands and up to elevations of 1,200 metres ⁽⁹⁾. This species is considered to be a vagrant in Palau, New Caledonia, and on Christmas Island, Norfolk Island and Lord Howe Island ^{(2) (10)}.

Generally considered to be a sedentary species, the little black cormorant is known to disperse within Australia in response to droughts or temporary flooding, and in New Zealand it is reported to migrate to the coastal waters of the north for the winter ⁽²⁾.

Little black cormorant habitat

A widespread species in wetland areas, the little black cormorant is most commonly seen in inland settings ^{(2) (3) (7) (8)}, including lakes, swamps, reservoirs, rivers and lagoons ^{(2) (3) (5) (7) (8) (9)}, as well as ponds and even urban parks ⁽²⁾. However, this species can also be found in sheltered coastal waters ⁽²⁾, such as estuaries, lagoons, mangroves, harbours and salt-pans ^{(2) (5) (9)}.

In inland areas, the little black cormorant generally prefers shallow waters less than one metre deep ⁽²⁾. While this species is known to occasionally occupy temporary waters in deserts, it is not found in Australia’s arid central region ⁽³⁾.

Little black cormorant status

The little black cormorant is classified as Least Concern (LC) on the IUCN Red List ⁽¹⁾.

Little black cormorant threats

A widespread species in Australia ^{(2) (10)}, the little black cormorant is not currently considered to be threatened with extinction ⁽²⁾, although there is uncertainty surrounding the extent of potential threats to this species ⁽¹⁰⁾. The little black cormorant appears to be less affected than most species by the transformation of wetlands, but increasing salinity levels, clearing, grazing, burning and groundwater extraction are known to potentially be threatening its breeding grounds ⁽²⁾.

Given that the little black cormorant feeds extensively on introduced fish species, it is believed that campaigns to remove such fish from Australia’s waterways could have a negative impact on the small water bird ⁽²⁾.

Little black cormorant conservation

There are no conservation measures known to be in place at present specifically for the little black cormorant. However, in Australia this species has benefitted from the construction of dams and reservoirs, which have increased the amount of available breeding and foraging habitat ⁽²⁾.

Find out more

Find out more about the little black cormorant:

• BirdLife International - Little black cormorant:
  http://www.birdlife.org/datazone/speciesfactsheet.php?id=3678   

Learn more about bird conservation in Australia:

• BirdLife Australia:
  http://www.birdlife.org.au/

Find out more about conservation in Australia:

• Australian Wildlife Conservancy:
  http://www.australianwildlife.org/
• Australian Conservation Foundation:
  http://www.acfonline.org.au/

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Glossary

Crustaceans

Diverse group of animals with jointed limbs and a hard external skeleton, characterised by the possession of two pairs of antennae, one pair of mandibles (mouthparts used for handling and processing food) and two pairs of maxillae (appendages used in eating, which are located behind the mandibles). Includes crabs, lobsters, shrimps, woodlice and barnacles.

Incubation

The act of incubating eggs; that is, keeping them warm so that development is possible.

Molluscs

A diverse group of invertebrates, mainly marine, that have one or all of the following: a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.

Vagrant

An individual found outside the normal range of the species.

References

1. IUCN Red List (March, 2013)
   http://www.iucnredlist.org/
2. del Hoyo, J., Elliott, A. and Sargatal, J. (1992) Handbook of the Birds of the World. Volume 1: Ostrich to Ducks. Lynx Edicions, Barcelona.
3. Rogers, K. and Ralph, T.J. (2010) Floodplain Wetland Biota in the Murray-Darling Basin: Water and Habitat Requirements. CSIRO Publishing, Collingwood, Australia.
4. Dutson, G. (2012) Birds of Melanesia: Bismarcks, Solomons, Vanuatu, and New Caledonia. A&C Black Publishers, London.
5. Robertson, H. and Heather, B. (2001) Hand Guide to the Birds of New Zealand. Oxford University Press, Oxford.
6. Hutton, F.W. and Drummond, J. (2011) The Animals of New Zealand: An Account of the Dominion’s Air-Breathing Vertebrates. Cambridge University Press, Cambridge.
7. Gould, J. (1865) Handbook to the Birds of Australia. John Gould, London.
8. Thomas, R., Thomas, S., Andrew, D. and McBride, A. (2011) The Complete Guide to Finding the Birds of Australia. CSIRO Publishing, Victoria, Australia.
9. Sibley, C.G. and Monroe Jr, B. (1991) Distribution and Taxonomy of Birds of the World. Yale University Press, Connecticut.
10. BirdLife International (March, 2013)
    http://www.birdlife.org/datazone/speciesfactsheet.php?id=3678
11. Barker, R. and Vestjens, W. (1989) Food of Australian Birds 1. Non-passerines. CSIRO Publishing, Collingwood, Australia.