An agile aquatic hunter, the large pied cormorant feeds mostly on fish (2) (3) (4) (5), which it catches by pursuing them underwater (2). Impressively, these dives last an average of 26.5 seconds (8). While approximately 90 percent of its diet comprises a wide variety of fish species (2) (5), the large pied cormorant also feeds on crustaceans, such as shrimps and crabs, as well as some molluscs, including cephalopods (2) (5). Several introduced fish species, including carp (Carassius auratus) and perch (Perca fluviatilis), are an important component of the large pied cormorant’s diet, particularly in the estuaries of southwestern Australia (2).
The large pied cormorant is known to form feeding flocks at sea (2) (5), and can be seen resting on sandbanks or low rock edges after fishing (4). The large pied cormorant roosts and breeds colonially, with roosting generally occurring in trees near water and in association with other cormorant species, spoonbills and Australian pelicans (Pelecanus conspicillatus) (2) (3). The breeding season of the large pied cormorant varies considerably with geographical location, as well as between years, with local water conditions and resource availability being important factors in its onset (2) (3) (5). However, although breeding may occur at any time of the year, the main breeding season appears to be between spring and autumn (2) (3).
The large pied cormorant tends to nest in trees, bushes or sometimes on the ground (2) (4), on islands or in swamps (2) at sites where the water levels are relatively stable, such as along the coast (3). However, this species is also known to breed at inland locations, although this tends to occur opportunistically in response to extended flooding conditions (3). Large pied cormorant nests are formed of twigs, seaweed (2) (3) and occasionally rubbish (3), and are sometimes lined with grass (2).
The large pied cormorant typically produces a clutch of between 1 and 5 eggs, although 3 is most common (2), with the eggs being laid at intervals of 48 hours (3). Large pied cormorant eggs are pale bluish-white (4), and are incubated for between 25 and 33 days (2) (3). Once the chicks reach 34 days of age, they are able to walk from the nest, but return to it for the next 4 weeks (3). The chicks are able to fly at about 47 to 60 days old, although the young are not fully independent from the adults until they are 80 days old or more (2) (3). While some large pied cormorants are capable of breeding at one year of age, most do not reach sexual maturity until they are two years old or more (2).
The large pied cormorant is a non-migratory species, with adults usually remaining in the same location. However, juveniles tend to disperse from the breeding grounds in which they hatched (2) (5).