for National Geographic News
A new satellite-tracking study of migrating white-naped cranes highlights the importance of international cooperation to ensure their survival. These graceful, rare birds face many perils along their flyways, not least the fact that many rely on resting sites in one of the world's tensest political flash points—Korea's Demilitarized Zone (DMZ).
White-naped cranes (Grus vipio) undertake epic 1,600-mile (2,600-kilometer) migrations from breeding grounds in eastern Russia and Mongolia to warmer wintering grounds in China's Yangtze River Basin or southern Japan. Though these birds benefit from legal protection at wintering spots, new satellite data reveal that they face habitat loss, hunting, and other risks at resting sites in the DMZ and other places.
Working around political tensions to set up strings of reserves is an essential step in conserving cranes and other migratory species, said ten Russian, Japanese, and other experts behind a new study. The study was detailed in last month's edition of the science journal Conservation Biology.
"Long-distance migrant birds, including cranes, range over such large areas, [that conservation] necessitates multinational communication and cooperation," the researchers and conservation workers, led by Hiroyoshi Higuchi at the University of Tokyo, wrote.
"If rest sites continue to be lost from migration pathways, the birds will eventually have no way to refuel en route, and will die before they reach their destinations," said co-author Johanna Pierre of the New Zealand Department of Conservation in Wellington. "Maintaining the chain of rest sites on migration pathways is critical to ensure crane survival," she said.
Long-Haul Conservation
Most cranes migrate, covering distances ranging from 250 to 2,500 miles (400 to 4,000 kilometers).
Two-thirds of the world's 15 species of crane are vulnerable or endangered, according to the World Conservation Union (IUCN). This is despite their cultural importance in many nations. Cranes have been declared a natural monument in Korea and "are a symbol of happiness in many countries, including Japan and China," Pierre said.
White-naped cranes—4-foot-tall (1.25-meter-tall) gray-and-white birds with red eye patches—may now number about 5,000. The IUCN has proposed listing white-naped cranes as vulnerable. The International Crane Foundation, a private, nonprofit organization based in Wisconsin, says they are the fourth rarest crane.
Migratory species pose a special challenge to conservationists. Tracking the moving birds relies on international coordination, sometimes in politically sensitive regions.
Satellite tracking has emerged in recent years as a tool to map migration patterns of animals, from hawksbill turtles to caribou. Satellites can be used to locate stopover points and habitats, generating data to help conservation.
To map conservation hot spots along one of several flyways, the researchers harnessed satellite transmitters to 11 migrating white-naped cranes. With the help of a helicopter (and an annual molting season that prevents the birds from flying), Pierre, Higuchi, and colleagues captured cranes from remote marshes in the nature reserves of eastern Russia.
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