Oriental white stork information

Ecology of the oriental white stork

Japanese name Kounotori (Nihon Kounotori) Taxonomy Ciconiiformes, Ciconiidae
English name Oriental white stork (or oriental stork) Scientific name Ciconia boyciana

Distribution and global population size

Oriental white storks breed in Russian Far East and Northeast China and winter in the middle Yangtze River basin in China, Taiwan, Korea, and Japan. Poyang Lake in China is a famous wintering ground of this species. They once bred in Japan and South Korea. According to the International Union for Conservation of Nature (IUCN), the global population size (mature birds) is estimated to be between 1,000 and 2,499.

Size and features

The wing span is 200-220 cm, and weight is 4-5 kg. The flight feathers, scapulars, primary coverts, greater coverts, and alulas are black, and the remaining parts are white. Because the muscles that move the syrinx are not well-developed, they cannot make calls and songs. Therefore, cluttering, or striking of the upper and lower beaks like a castanet, is used for communication.


There are no apparent differences between males and females, but generally, males are slightly larger than females. For reliable sexing, feathers and blood are collected and DNA tests are performed.


The lifespan in the wild in Japan is unknown due to the short history of reintroduction since 2005, but some oriental white storks lived for over 30 years in captivity.

Feeding habit

The oriental white stork is a carnivorous bird that lives in wetlands and preys on fish, such as crucian carps and loachs, reptiles such as snakes and lizards, amphibians such as frogs, insects such as grasshoppers and locusts, and small mammals, such as mice.

Breeding biology

During the breeding season from February to July, breeding stage advances in order of nest building, mating, egg-laying, egg-incubating, hatching, feeding chicks, and fledging. In the past in Japan, nests were built on the top of tall trees; at present, however, there are almost no tall trees suitable for nesting, and nests are built on artificial objects such as artificial nest towers, electric poles, and steel towers. The diameter of the nest is 150-200 cm. Clutch size is usually 2 to 5, and eggs are incubated by both the parents. Hatching occurs approximately 30 days after the start of egg-incubation, and chicks fledge in about 70 days.
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History of oriental white stork conservation in Japan

EDO period There are records that oriental white storks were distributed all over the country.
MEIJI period As ordinary people became able to hunt, oriental white storks were over-hunted and the number of individuals declined.
1921 "Tsuruyama" in Izushi-cho, Izushi-gun, Hyogo Prefecture, was designated as a national natural monument as a breeding ground of oriental white storks.
1939-1945 Tall pine trees suitable for oriental white stork nesting were cut down, and the number of nesting sites reduced.
1950s and 1960s Prey animals and the storks that feed on them were negatively affected by the use of potent pesticides and environmental changes, and the wild oriental white stork population declined in size.
1952 "The oriental white stork and its breeding area of Iza" in Iza-mura, Yabu-gun, Hyogo Prefecture, was designated as a national special natural monument.
1953 The designation of the national special natural monument for the oriental white stork was changed from "area-type" to "species itself."
1955-1964 To conserve the ever-declining oriental white stork population, public and private conservation activities such as the "gentle watching campaign" and the "one person-one loach campaign" were developed. However, the population size continued to decline.
1965 One wild pair was captured in Toyooka City, Hyogo Prefecture, on February 11, to preserve the wild stork population, which had decreased to 12 birds in total. Captive breeding started in the Stork Breeding Center (Current: Oriental White Stork Captive Breeding Center affiliated to Hyogo Park of the Oriental White Stork).
1971 The last wild oriental white stork died after being rescued in Toyooka City, Hyogo Prefecture, and the breeding population of the oriental white stork in Japan went extinct.
1988 Tama Zoological Park succeeded in breeding oriental white storks for the first time in Japan.
1989 The Stork Breeding Center in Hyogo Prefecture also succeeded in breeding oriental white storks.
1990 The Japanese Association of Zoos and Aquariums (JAZA) started the Japanese studbook registration for oriental white storks reared all over Japan.
1995 The World Association of Zoos and Aquariums (WAZA) started the international studbook registration for oriental white storks reared all over the world.
1999 Hyogo Park of the Oriental White Stork was established by Hyogo Prefecture aiming at reintroducing oriental white storks into the wild. Fertilized eggs were successfully transported from Tama Zoological Park in Tokyo to Korea National University of Education.
2002 Captive population size reared in Hyogo Park of the Oriental White Stork exceeded 100.
2005 Hyogo Park of the Oriental White Stork released five oriental white storks into the wild (reintroduction started).
2007 The first breeding success in the wild was recorded on an artificial nest tower in Toyooka City, Hyogo Prefecture.
2013 IPPM-OWS was established.
2015 Fukui Prefecture and Noda City (Chiba Prefecture) started reintroduction projects. Reintroduction also started in South Korea.
2017 Successful breeding was recorded for the first time in Tokushima Prefecture, outside the northern part of Kinki District (Toyooka City, Hyogo Prefecture, and Kyotango City, Kyoto Prefecture). In addition, the wild population size exceeded 100, and observation records of the reintroduced storks was achieved in all prefectures of Japan, in 12 years after the start of the reintroduction.
2020 The wild stork population size exceeded 200.
2022 The wild Oriental White stork population size exceeded 300.Breeding of Oriental White storks are observed in seven prefectures in Japan.