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).