the Great cormorant

Cormorants are large birds that can swim hundreds of feet below the surface hunting for large fish. But they are also capable to fly tousands of miles. The Cormorant has a long, hook-tipped bill that it uses for catching fish.

cormorant and fish

Most of the fish that is hunted by the cormorant has no economical value at all, for example sticklebacks. Cormorants are the only birds that swallow sticklebacks in large amounts. But fishermen see in the great cormorant a competitor for theire fish. Because of this the coromorant was hunted nearly to extinction in the past. Cormorants commonly forage 2 meter to 5 meter deep, but sometimes up to to 25 meter. They grab fish with their shap pointed bills. Dive times of 30 seconds are common, with a recovery time on the surface of about 10 seconds.

cormorant distribution

The great cormorant or Phalacrocorax carbo has a worldwide distribution. There are many subspecies caused by vicariance. So all these cormorants are capable to interbreed, producing offspring. The type subspecies, P. c. carbo, is found mainly in Atlantic waters, for example the North sea. They can be found on the Islands in the Atlantic, like Iceland and Greenland. But also around fresh water lakes, like those of the Netherlands.and brakish water"the Baltic sea Another subspecies, white-breasted cormorant P. c. lucidus can be found south of the Sahara. The subspecies P. c. sinensis can be found in Western Europe and the of east Asia). P. c. hanedae can be found around the Japanese Islands.

Sunbathing cormorants

The function of Wing-drying or sunbathing of the Great cormorant is to dry the wings after wetting. The plumage of the cormorant is not water-repellent, and need to be dried after diving. The feathers have modified barbs which allow air to escape and water to penetrate the plumage during diving. This means that are efficient and fast underwater swimmers. But it does also mean that the birds become waterlogged need dry its plumage.
The painting is made by Thorburn.

colonies of cormorants

The Great cormorant build large, shallow nests on cliffs or in trees. The trees are vastly killed because is the very acid droppings, called guano. But the cormorant also use the branches and by breaking them to build the nest. On this painting a colony of cormurants build theire nest near a dutch duck decoy in an estuaries. Here they feed on sandeels and European sprat.

nest of cormorants

Three or four eggs are laid in a nest of seaweed or twigs. Cormorants build nests of seaweed, reed and twigs.

Fishing with cormorants, a blockprint made by Kawase Hasui.
Fishing is mainly done with the Great cormorant. To control the birds, the fishermen tie a snare near the base of the cormorant throat. This prevents the birds from swallowing larger fish, which are kept in their throat, but the birds can swallow smaller fish. When a cormorant has caught a bigger fish in its throat, the fisherman brings the bird back to the boat and has the bird spit the fish up.

Mute swan or Cygnus olor,
The mallard or Anas platyrhynchos,
Greylag goose or Anser anser,
Reed cormorant (Microcarbo africanus) or long-tailed cormorant, africanus Phalacrocorax or Microcarbo africanus.

Cormorants by Louis Agassiz Fuertes
1 The double-crested cormorant or Phalacrocorax auritus
2 with young
3 Great cormorant or Phalacrocorax carbo,
4 with young
5 Northern gannet, with young , in wintercolor
6 Northern gannet, adult