December 7, 2010
Giant Stork Discovered On Hobbit Island
A giant marabou stork has been found on an island that was once home to human-like "hobbits."
Fossils of the stork were discovered on the Indonesian island of Flores, which is a place that became famous for many discoveries like the Homo floresiensis, a hominin species related to modern humans.
The finding also helps explain how prehistoric wildlife adapted to living on islands.
Researchers estimate that the new species of giant stork stood 6 feet tall and weighed up to 35 pounds, making it taller and much heavier than today's stork species.
Paleontologist Hanneke Meijer of the Smithsonian National Museum of Natural History in Washington D.C., and affiliated to the National Museum of Natural History in Leiden, made the discovery with colleague Dr. Rokus Due of the National Center for Archaeology in Jakarta, Indonesia.
They discovered the fossilized fragments of four leg bones in the Liang Bua caves on the island of Flores.
The bones are between 20,000 and 50,000 years old and they are thought to have belonged to a single stork.
The giant bird is the latest extreme-sized species to be discovered once living on the island, which was once home to dwarf elephants, giant rats and out-sized lizards.
"I noticed the giant stork bones for the first time in Jakarta, as they stood out from the rest of the smaller bird bones. Finding large birds of prey is common on islands, but I wasn't expecting to find a giant marabou stork," Meijer told the BBC.
The researchers suspect that the giant stork rarely, if at all, took flight.
They suggest that the stork was so heavy that it lived most of its life on the ground.
It is thought to have evolved from flying storks that colonized the relatively isolated island.
"Flores has never been connected to mainland Asia and has always been isolated from surrounding islands. This isolation has played a key role in shaping the evolution of the Flores fauna," Meijer said.
Many species on the islands evolved into either giants or dwarfs.
This phenomenon is thought to have been triggered by few mammalian predators being on the island. That led to abundant prey species becoming smaller, and other predators becoming larger.
"Larger mammals, such as elephants and primates, show a distinct decrease in size, whereas the smaller mammals such as rodents, and birds, have increased in size," Meijer told BBC.
The remains of the giant stork were found in the same section of cave as the remains of H. floresiensis.
H. floresiensis is thought to be a new human-like species standing just 3-feet tall, which survived until about 17,000 years ago.
Modern marabou storks mainly eat carrion, but they do sometimes partake in eating fish, frogs, and small mammals and birds, leading scientists to speculate whether the giant stork would have eaten the hominin.
"Whether or not this animal may have eaten hobbits is speculative: there is no evidence for that," Meijer told the BBC.
"But can not be excluded either."
It is unclear why the giant stork, and pygmy elephants and hobbit hominins went extinct.
"But we have several clues," Meijer told BBC.
"All the bones of the giant marabou as well as those of the pygmy elephants and the hobbits are found below a thick layer of volcanic ash," suggesting a recent volcanic eruption.
"Second, the giant marabou and its contemporaries go extinct right before modern humans appear at the cave."
About 15,000 years ago, the climate of Flores went from dry to being wetter, and a combination of any of these factors may have been enough to drive species on the islands to extinction.
Image Caption: Scientists compare the fossil find to the modern marabou stork, which were mainly carrion eaters.
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