The Japanese crane, also known as the red-crowned crane is one of the rarest cranes in the world. The bird gets its name from the distinct red patch that is found on its crown. In Japan, the crane is considered a “bird of happiness” that can live for a thousand years. The bird is also considered a sign of luck. The Japanese also believe that the crane carries the souls of the dead to paradise. As a result, in Japanese, Korean, and Chinese culture, the bird represents good fortune and longevity. It is also believed that if one completes folding 1000 origami cranes, one is granted one wish. The term “origami” comes from two Japanese words; “ori” meaning “to fold” and “kami” meaning “paper.” While making origami cranes is not a difficult task, during the 6th century, when the origami culture is thought to have begun, the cost of paper was very high. Making a thousand origami cranes was, therefore, not easy for ordinary residents. Today folding 1,000 cranes (in Japanese, called “senbazuru”) has become extremely popular. The cranes are usually struck together on 25 strings with 40 cranes each and given to friends and family as gifts.
Current Status Of The Japanese Crane
The Japanese crane, which is scientifically known as Grusjaponensis, is classified as endangered by the IUCN. Until the mid-1800s, Japanese cranes were found in abundance throughout Hokkaido and Honshu and other parts of Asia such as China, Korea, and Siberia. Today there are about 2,750 members of the species that survive in the wild. The species was thought to have disappeared in the 20th century due to overhunting and habitat destruction. The birds were indiscriminately hunted from the Edo period (1603 to 1867) to the early 20th century. Twenty birds were rediscovered in the 1920s in the Kushiro Wetland roosting and feeding near small rivers in the marsh. In 1924, the area was designated as a protected area. By 1952 the population had risen to 33 birds. In the same year, Hokkaido was struck by a blizzard and severe cold, which prompted farmers to begin feeding them buckwheat and corn to help them survive. In the winters that followed, farmers continued feeding the birds, which led to a dramatic rise in their numbers. In 1982, there were about 1000 cranes in existence, with 300 of them residing in Japan. Over the years, the species has been studied and tracked. However, efforts to raise them in captivity for release have failed.
There are both migratory and resident populations of the bird. Resident populations are found in Hokkaido, Japan, while migratory populations nest and breed in Northeastern China, Northeastern Mongolia, and Siberia. During winter, the birds migrate to East-Central China and the Korean Peninsula. Japanese cranes are omnivorous birds, and their diets vary depending on the season. During spring and summer, the birds can be found near wetlands where they feed on fish, aquatic invertebrates, amphibians, crabs, snails, earthworms, mice, and waterfowl. During winter, the birds can be found in mudflats and agricultural fields where they feed on a variety of plants, acorns, and rice. The nesting habitat typically consists of open wetlands. Some nests can, however, be found in wooded wetlands. The nests are mainly made up of dead reeds and are found in the water and surrounded by dense vegetation. During winter, they prefer shallow streams and rivers with open water for roosting.
Japanese Cranes In Japan
By 2005, the population of Japanese cranes in Hokkaido had exceeded 1,000 birds as a result of intense conservation efforts. In 2008, for the first time in over a hundred years, a red-crowned crane was spotted in Honshu in a rice field in Akita Prefecture. Today the Japanese crane population in Japan is about 1,200. About 1,400 others are found outside Japan and migrate between Siberia, China, and the Korean Peninsula. During winter, the cranes congregate in areas where farmers provide them with some grain. There are currently four established feeding centers that are complemented by several dozen public and private satellite feeding stations spread throughout Eastern Hokkaido. About 300 cranes gather at the Tsurui-Ito Sanctuary situated near Kushiro National park in the winter to get free corn.
Out Of Luck
Over the years, Japanese cranes have become used and reliant on humans due to free food and interaction with humans. Some have reported incidents of birds pecking on their windows, expecting handouts. Such behavior is annoying some of the people living near the bird habitats. The cranes are even regarded as pests. Farmers have also begun complaining that the birds are invading their fields and stealing grain that is meant for livestock.
Threats Facing The Japanese Crane
The Japanese crane has enjoyed a good run over recent years, with the birds coming back from the brink of extinction. In the same period, threats facing the species have increased dramatically. Some of the threats include loss and degradation of habitat, pollution, poaching and capture, and low genetic variation.
Populations that have in the past experienced drastic decreases often have a low genetic variation, which increases the risk of extinction. Experts believe that the Japanese crane, which rebounded from just twenty birds, is also suffering from low genetic variation. Deficiency of genetic diversity in small populations can lead to inbreeding depression, increased disease susceptibility, and reduction in the long term survival of wild populations when faced by changing environmental conditions. The adverse effects of low genetic diversity can also lead to a population decline. Such a negative feedback loop referred to as an “extinction vortex,” and its genetic influences are often more severe in smaller populations. Red-crowned cranes in Japan are currently limited to a small area. Examination of the cranes using neutral genetic markers has revealed that the population found in Japan has lower genetic diversity compared to the continental population. Experts believe that since the island population of Red-crowned cranes is distributed in limited ranges where there are high numbers of cranes, the extinction threat would be very high if novel pathogens were introduced to the population. Artificial feeding stations in Hokkaido are high-risk areas where diseases can be easily spread. In some areas, the reproduction rate has begun declining partly because of a lack of fertility due to inbreeding.
Changing Agricultural Practices
Japanese cranes often depend on waste grain for their diet during the wintering period. Any changes in farming practices can, therefore, have significant effects on the crane population. For example, the birds have suffered from a reduction in waste grain due to the shift to autumn plowing in areas found in the Demilitarized Zone of the Korean Peninsula.
Habitat Loss And Degradation
Over the years, wetlands that are vital for the survival of the Japanese crane have been converted into agricultural land or utilized for aquaculture. The construction of buildings and other forms of settlements has also drained a significant part of the wetlands. It is estimated that Japanese cranes have lost over 30% of marshland in the last 60 years. The construction of dams that divert large amounts of water also has catastrophic effects on wetlands found downstream. In China, the construction of dams has led to the drying up of large sections of wetlands that have served as a habitat for Japanese cranes. The reduction in water levels in such areas not only affects the availability of food but also makes nesting sites vulnerable to predator attacks. Human disturbance in wetlands also adversely affects the nesting of the cranes due to increased stress levels.
Some of the areas inhabited by Japanese cranes are found on or near oil fields. The Song-nen and the Yellow River delta are examples of such areas. Frequent oil spills in such regions have been observed to harm the bird’s wellbeing. Increased soil, water, and air pollution have also led to instances of crane poisoning. In several continental wintering regions, a rise in adult mortality has been recorded with poisoning noted as the cause of death.
Today the crane population is rising at a rate of about 5% to 7% every year. The habitat is, however, shrinking rapidly. In Kushiro Mire, the marshland is nearing maximum capacity. Having them in a crowded area can significantly increase the risks of chicks not surviving. Adults are forced to leave their nests more frequently in search of food over a wider area, which leaves nests vulnerable to predators.
Conservation Of The Japanese Crane
Governments of countries where Japanese cranes are found have undertaken several measures on the conservation of birds. For example, it is illegal to hunt red-crowned cranes in all nations where they naturally occur. Protected areas have been developed to safeguard the crane’s habitat. Winter feeding stations have also been established to help the birds survive through winter. International agreements have been established on research into the species and its migratory patterns, to establish better conservation practices. Such agreements have, however, run into several challenges during implementation. For example, a significant proportion of cranes that winter in Hokkaido have begun moving to the Russian-controlled Kuril Islands that are claimed by Japan, which lost them during World War II. Tense relations between the countries over the islands have often affected in-depth research and cooperation between scientists and environmental conservationists.