Cormorants (Phalacrocoracidae) are waterfowls forming the family Phalacrocoracidae of the order Pelecaniformes. Though the estimated number of species varies among researchers, approximately forty species of cormorants live all over the world from the tropics to both poles.
With all the species of the Phalacrocoracidae generally lumped under one genus, the Phalacrocorax, there are some different theories that the Flightless Cormorant is classified into the genus Nannopterum or that all other species are subdivided into genera such as the Hypoleucos, the Leucocarbo, the Stictocarbo, and the Compsohalieus. Three species of cormorants including the Japanese Cormorant, the Great Cormorant and the Pelagic Cormorant breed in Japan, all of which are blackish brown or black with a green or indigo luster.
Ukai (Cormorant Fishing) and Cormorants
Since cormorants swallow the whole fish without chewing it, the phrase 'Unomi ni suru (to swallow the whole thing like cormorants do)' was coined meaning to take someone's story on faith without ascertaining the truth.
And, this habit of cormorants is used for fishing. The following are advantages of cormorant fishing. In this fishing method, it is possible not only to catch a fish without damaging it unlike when they fish with nets or fishing rods but also to keep it tasty and make its bones soft because the fish falls unconscious instantly and gets tired (especially in pole-and-line fishing) when it is put under intense pressure in the cormorant's throat.
For more information on the relationship between cormorant fishing and cormorants, refer to Cormorant Fishing, and Cormorant Fishing on the Nagara River.
Cormorants in Japan
Phalacrocorax capillatus (Coenraad Jacob Temminck and Hermann Schlegel, 1850)
Japanese Cormorants range from 80 to 90 cm in length. They live on coasts and fly very low over the water.
Their sharp, hooked beaks are suitable for catching fish.
They build their nests in colonies on rocky ledges or cliffs using twigs and withered grass.
Those of this species caught and raised are used for cormorant fishing in Japan.
Phalacrocorax carbo (Carl Linnaeus, 1758)
Great Cormorants are about 80 cm in length. They are similar to Japanese Cormorants but slightly smaller. They live around rivers, lakes or swamps.
Great Cormorants act in flocks of some tens to hundreds and nest in trees with heaps of twigs and feathers.
This species is used for cormorant fishing in the People's Republic of China.
Phalacrocorax pelagicus (Pallas, 1811)
Pelagic Cormorants are about 50 cm in length. They are slightly smaller than Great Cormorants.
Flocks of several Pelagic Cormorants act together and sometimes nest in a colony of Japanese Cormorants.
Phalacrocorax urile (Gmelin, 1789)
Some Red-faced Cormorants migrate from their breeding grounds on the Aleutian Islands to Hokkaido or Tohoku region in order to pass the winter.