Once upon a time, a subspecies of giant tortoise lived on Fernandina, the least-explored island in the Galapagos.
In 1906, explorers with the California Academy of Sciences found one male Fernandina Galapagos tortoise - and killed it to preserve as a specimen. The next sign came in 1964, when an expedition to the island reported the presence of tortoise scat. An aerial survey in 2009 spotted something resembling a tortoise. But for all practical purposes, this reptile has been lost to the world for 111 years.
Now the quest to find it - and two dozen other "lost species"- is about to be renewed. Global Wildlife Conservation, a Texas-based organisation, is launching a global search for what it calls the top 25 "most wanted" animals (and one plant). None is officially extinct. But, collectively, the species have not been seen in more than 1500 years.
The list, which was compiled in consultation with dozens of experts from the International Union for Conservation of Nature, includes a bat, a bee, a parakeet, a sea horse and a kind of coral. The experts were asked to nominate species that had not been spotted in more than 10 years and had cultural significance. Species already declared extinct, such as the Tasmanian tiger, were not considered.
Most important, project lead Robin Moore said, was a "glimmer of hope," for their rediscovery.
"We are in an extinction crisis, and I think people need to feel at least there's some hope," said Moore, a biologist and director of communications at GWC. "Hope is a more powerful motivator than despair."
From an initial list of 1200 nominations, the organisation narrowed things down to what Moore called 25 "quirky, charismatic" poster species that, if they still exist, are found in 18 countries across the globe. It does not include species for which many people are already looking, Moore said, such as the ivory-billed woodpecker, a bird reported to have been seen in Arkansas in 2004 (although that sighting is in doubt).
Moore said the organisation hopes to start expeditions in the late northern summer, after an initial effort to raise US$500,000. The kind of search will vary, he said.
Scientists might launch a two-week quest in the grasslands and swamps of Burman to look for the pink-headed duck, which has been "lost" for 68 years.
Larger mammals, like the Wondiwoi tree kangaroo of Indonesia, might be best spotted with remote cameras. Talking to locals could be key to finding the scarlet harlequin frog in the cloud forest of Venezuela. Divers and vessels will be required for the search for Wellington's solitary coral, which was abundant in some parts of the Galapagos until an El Niño event in the early 1980s.
Moore has firsthand evidence this campaign could work. In 2010, when he was at Conservation International, he and colleagues launched "The Search For Lost Frogs," which took scientists across the world in search of 10 missing frogs. Within a year, they had located three, and they rediscovered 12 others.
Tips and sighting reports are welcome, Moore said. Here are five species for which to look. The others can be seen at http://lostspecies.org/, though in many cases, the only image available is an artist's rendering.
- Namdapha flying squirrel
This squirrel has been missing for 36 years. A single specimen collected in a national park in northeast India is the only evidence it ever existed.
This small sturgeon is native to the Syr Darya river of Central Asia. It was last seen in the 1960s in Kazakhstan.
- Pink-headed duck
The males of this species have deep pink heads and necks that you might think would be easy to spot, even in the wilds of Burma. But despite vigorous searches after unconfirmed sightings in 2006, it has remained elusive since it was last seen in 1949.
This quail, which is known to have lived in at least in two locations of India, is the longest-missing species on the list. It was last seen in 1876.
- Scarlet harlequin frog
This frog was last seen in 1990 and is known from a single stream in the Venezuela cloud forest. But anecdotal reports suggest it could still live in a remote area scientists have not yet examined, Global Wildlife Conservation says.