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Tuesday, May 8, 2012
JAPANESE CRESTED IBIS
Efforts to save Japanese crested ibis take flight
By AYAKO MIE
Japanese spirits were uplifted recently by the news that three "toki," or Japanese crested ibis, chicks were hatched in the wild for the first time in 36 years, the culmination of a ¥300 million project that was started in 1999 to breed the endangered wading birds outside captivity.
As its scientific name, Nipponia nippon, implies, Japanese crested ibises are a symbol of the nation. They had flourished for centuries but overhunting and loss of habitats led to their virtual extinction by the 1930s.
What characterizes the species and how did it come by its name?
Part of the scientific name, Nipponia, was coined by a Dutch zoologist in 1835, after German physician Philipp Franz von Siebold sent an ibis specimen to the Netherlands. The Ornithological Society of Japan made the scientific name official in 1922.
Adult crested ibises stand around 75 cm tall and have a wingspan of 140 cm. They are white with black, downward curving beaks and red faces and legs.
Where are they originally from?
Ibises historically nested in the Russian Far East, Japan and China, and were nonbreeding visitors to the Korea Peninsula and Taiwan, where they are virtually extinct.
The only remaining population in the wild is in Shaanxi Province in central China. As of 2006, they numbered 500, according to the IUCN Red List of Threatened Species.
Why did the bird become endangered?
During the Edo Period (1603-1867), ibises were so numerous that rice farmers asked the government to cull them to prevent them from destroying their paddies.
Toward the end of 19th century, when the ban on killing birds and animals was lifted and firearms became more available, ibises were overhunted for their beautiful feathers.
Land development and overuse of pesticides destroyed rice fields where the birds fed on small animals such as loaches, frogs and crabs, their staple diet. By 1930, their numbers had decreased to the point that a local chronicle in Niigata Prefecture noted that ibises were extinct.
The government designated ibises as a special protected species in 1952. Eight years later, it became an internationally protected bird.
How did the protection program start?
In the 1950s, ibises were spotted only in Niigata's Sado Island, where the municipalities and residents had been protecting them. The government originally set up the Sado Japanese Crested Ibis Conservation Center in 1967.
By 1981, the number of ibises in the wild was down below five even on Sado. When the government captured the five, the conservation center was designated to breed the ibises and eventually return them to the natural environment.
Despite those efforts, Japanese-born ibises went extinct when Kin, a female, died in 2003, presumably at the age of 36. All ibises in Japan now are offspring of a Chinese pair, Yuuyuu and Yangyang, gifts from the Chinese government in 1999. They continued to breed after Kin died, and today there are 178 ibises, including those at four other facilities.
What efforts have been made to return ibises to the wild?
The Environment Ministry, which is in charge of the national campaign to save ibises, in 2004 set a target of 60 birds in the wild in the eastern district of Kosado on the island by 2015.
To achieve the goal, the city of Sado and residents started projects to restore the natural environment to sustain various creatures. Rice farmers were asked to cut down the use of pesticides by 50 percent to create conditions where creatures such as loaches and crabs could survive in their rice paddies.
How can ibises raised in the conservation center learn to survive in the wild?
The government created a reintroduction center in 2007, where ibises can evoke their instinct to feed themselves and avoid natural predators. One year later, 10 ibises were freed into the wild for the first time. So far, roughly 78 ibises have been released, including the pair that recently produced the three chicks. The pair were returned to the natural habitat in March last year.
Why has it been so difficult to reproduce in the wild?
According to the conservation center, roughly half of the 155 eggs laid by the ibises in the center were fertilized, but only 10 percent of those laid in the wild. The cause of the low fertilization rate is unknown.
Yoshinori Kaneko, a veterinarian at the conservation center, said it is also difficult for ibises to mate as their numbers are still low, limiting their options for mates. But this year, Kaneko said, greater success was achieved partly because the center released twice as many birds into the wild as last year.
What are the challenges still to be overcome?
Because it takes about 40 days for chicks to learn to fly, they are easy prey for martens, weasels and crows. Especially dangerous for chicks are the martens, which were brought to Sado Island in the 1950s to kill wild rabbits. In 2010, martens got into a cage holding chicks, killing nine of them.
Kaneko said it is challenging for adult birds to feed chicks because, at their peak, the chicks devour almost twice as much food a day as adult birds, making starvation a threat. Even after chicks begin to fly, Kaneko said, it might be difficult for them to survive the winter when food is scarce.
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