Saturday, October 14, 2006

A Tale of Two Rails

Over the summer I read three books about extinctions in modern times. I wanted to share a few stories that stood out and one of the most striking is the extinction of two Pacific rails.

The Wake Island Rail (Gallirallus wakensis) is one of the lesser-known casualties of World War II. For the last few centuries, humans--first Polynesians, then European explorers--had steadily wiped out the native birds of the island. By the outbreak of WWII, the rail was the only land bird that remained on Wake Island.

Like many island birds, the rail showed no initial fear of humans. This proved its undoing when hungry Japanese soldiers arrived ashore. If the U.S. had developed the A-bomb just a few months sooner, the Wake Island Rail might still be with us. Sadly, by 1945, the Japanese ate the last member of the species. Today it’s known only from a few stuffed museum specimens and pictures.


Across the Pacific, in the Hawaiian Islands, the Laysan Rail (Porzana palmeri), suffered perhaps a slightly kinder fate. The rail had battled extinction since the turn of the century when rabbits and guinea pigs were introduced to Laysan. By 1911, the rails numbered only 2000. By 1920, they were gone.

A scattered population survived on surrounding islands but they fell, one by one, to rats. By the time only one colony of rail was left, the American government tried to save the birds by forbidding ships from coming ashore to their island. Instead ships were instructed to anchor at sea and only transport soldiers and supplies by small craft. Despite the impact of WWII, the U.S. Navy continued this practice, keeping the rail alive.

Unlike Japanese soldiers, Americans servicemen had a good relation with the rail. Just as its Wake Island cousin had little fear of humans, the Laysan Rail would approach men, out of curiosity or when tempted with food. Soldiers and sailors from the city enjoyed feeding the large bird and apparently overcame any urge to eat them to extinction.

Disaster struck in 1943—by accident, a Navy landing craft drifted ashore, allowing rats to touch land. By the end of the year, the last Laysan Rail was dead.

Without the war, the craft never would have landed. Without the war, it’s likely that scientists would have collected a small group of rail in captivity or would have returned them to Laysan (rabbits had been exterminated in 1924 so their old home would have been safe). Instead, rats killed the Laysan rail just as surely as hungry Japanese soldiers did to the species in Wake Island.

Of recent man-made extinctions, those of island birds are the most common and the rails are really no more tragic than any of the thousand other species we've wiped out. But what struck me the most about them was that their deaths were both caused by opposite sides of the same war, one by direct predation and the other by mistake.


Sources

Tim Flannery and Peter Schouten. A Gap in Nature: Discovering the World’s Extinct Animals. New York: Atlantic Monthly Press, 2001.

Jean-Christophe Balouet. Extinct Species of the World. 1989.

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