Great Cormorant

## Description

The great cormorant (Phalacrocorax carbo ), known as the black shag in New Zealand and formerly also known as the great black cormorant across the Northern Hemisphere, the black cormorant in Australia, and the large cormorant in India, is a widespread member of the cormorant family of seabirds. The genus name is Latinised Ancient Greek, from φαλακρός (phalakros, "bald") and κόραξ (korax, "raven"), and carbo is Latin for "charcoal".

It breeds in much of the Old World, Australia, and the Atlantic coast of North America.

## Appearance

The Great cormorant is a beautiful bird with an almost primitive appearance. Its long neck gives it an almost reptilian look. It is often seen in a pose holding its wings out to dry. This bird is a supreme fisher, and this ability may be used in the Far East to man’s advantage or considered as competition in several other countries where these cormorants are persecuted.

## Distribution

Great cormorants occur throughout Europe, Asia, Australia, Africa, and northeastern coastal North America. They may be both resident and migratory. Throughout the year in some areas, large groups remain within the breeding range. Greta cormorants frequent open marine environments and inland waters. They inhabit sandy or rocky sheltered coasts and estuaries and are rarely seen any distance from the coast. This species breeds on cliffs and inshore islands, among boulders and man-made structures. Birds that nest inland will breed on trees, in bushes, and reedbeds, and even on bare ground.

## Behavior

Great cormorants are active during the day and are social birds, usually leaving roosts to forage early in the morning and returning within an hour. Little time each day is spent foraging, although parents with young tend to forage for longer. Much of the day is spent resting and preening near foraging areas or at roosts. Great cormorants generally are not aggressive towards one another, apart from at nest sites, where they exhibit territorial behavior. There may be dominance hierarchies. Outside of the breeding season, they usually gather in mixed-age, mixed-sex groups.

## Diet

Great cormorants are carnivores (piscivores); they mainly eat numerous kinds of fish, and when fishing in freshwater, will also eat crustaceans, amphibians, and insects.

## Reproduction

Great cormorants are monogamous, with pairs sometimes reuniting in subsequent years. The male chooses the nest site, displaying to attract the female by waving his wings up and down and flashing his white rump patch. He will also swing his head from side to side while holding his tail erect and calling loudly. The female responds by swinging her head slightly and “purring”. This species breeds at any time, depending on food resources. Breeding takes place in colonies of as many as 2,000 pairs, although colonies of a smaller size are typical. Colonies are often located close to other species, like darters, herons, and spoonbills. The parents build their nest with reeds, sticks, and seaweeds on a cliff, in a tree, or in a bush, according to the region. Often a nest is reused. 2 to 6 eggs are laid, with an average of 3-4. The parents share the incubation for 27 to 31 days. The altricial chicks hatch at intervals and fledge at about 50 days old. They remain with their parents for 50 or more days, relying on them for food. The young start to breed between 2 and 4 years old, typically when 3 years old.

## Population

### Population threats

Great cormorants have large populations and are widespread, although surveys are not complete across their range. Being an important fish competitor, in the past, they were almost extinct in Europe. However, in recent years increases have been observed, thanks to intensive protection. But in some countries, expanding conflicts with fish farms and fisheries lead to new persecution. Another threat is that hatchlings may be eaten by raptors before fledging.

### Population number

The IUCN Red List reports that the global population of Great cormorants is about 1,400,000-2,100,000 individuals. The European population is estimated at 401,000-512,000 pairs, which equates to 803,000-1,020,000 mature individuals. Overall, currently, Great cormorants are classified as Least Concern (LC) on the IUCN Red List and their numbers today are increasing.

## Fun Facts for Kids

‘Cormorant’ comes from the Latin 'corvus marinus', meaning 'sea crow'.

Great cormorants have been seen swallowing small pebbles for extra weight in order to dive more easily, which they regurgitate after feeding.

On land Great cormorants are clumsy but they are fast and agile when swimming. An individual will rest on its tarsals with its neck in a relaxed kink in an S shape.

Due to their wettable feathers, Great cormorants spend much time drying and preening, sometimes preening for as many as 30 minutes. They must dry their feathers in a particular pose, their wings spread out, while perched on a branch, which may also help digestion.

These birds incubate their eggs with their large webbed feet. The eggs are placed on top of their feet, where they are warmed between their feet and their body.

These birds eat 400 to 700 grams per day of fish.

Great cormorants are often regarded as competitors by fishermen, though are sometimes used to catch fish, wearing a neck collar to stop them from swallowing the fish and send off from a boat to fish.