The Manus Green Tree Snail is now listed as “Near Threatened” in the International Union for Conservation of Nature’s (IUCN) comprehensive global inventory of the conservation status of species known as the “Red List”.
On 23 June, the IUCN released its updated Red List of Threatened Species that included the iconic Manus green tree snail.
The snail is now recognised as “Near Threatened” meaning although the population is declining there is no immediate extinction risk unless there is further habitat destruction and/or an increase in the harvest rate.
Its classification was special because of the way information was gathered.
“Tigers, pangolins, rhinos, pandas, elephants, the great apes: this is where conservation funds are going. Make no mistake these species are in trouble and they need help,” said PNG based Wildlife Conservation Society (WCS) scientist Nathan Whitmore.
“But the reality is that for most of the 9 million species on Earth we have no idea if they are in trouble and we do not enough funds to conduct field surveys to find out. In a competition for funds tigers beat snails, even pretty ones, every time.”
WCS has, however, found an inexpensive way around this by bringing together the knowledge of everyday people in a technique known as Wisdom of the Crowd, in a project funded by The Christensen Fund.
By surveying hundreds of locals at the Lorengau market on Manus Island, WCS built up a detailed picture of the Manus green tree snail: its range, the environmental factors affecting its distribution, and its rate of decline.
Whitmore said Wisdom of the Crowd techniques were now being used around the world for prediction in various fields including politics, economics, and computer science because they are inexpensive and surprisingly accurate.
He explained that one limitation of the technique is hundreds of participants with local knowledge need to be interviewed.
“Most people of Manus live a subsistence life in and around the forests and so they sample nature on a daily basis. You’re not going to get a useful estimate asking people in New York, or London about the Manus green tree snail. You’ve got to be surveying the people in the thick of the action,” Whitmore said.
To date, some people in conservation are sceptical about the results of this work.
“Understandably, they want comparison of this technique with field survey. But it’s a dilemma: we used Wisdom of the Crowd because there isn’t much money for projects on snails, but to do a comparison between field survey and Wisdom of the Crowd would require money for both,” Whitmore explained.
“While some wildlife managers might be able to access such funds for sexy, charismatic animals for the drabber members of the animal kingdom the choice will be between a rough low cost assessment technique like Wisdom of the Crowd or nothing at all.”
The WCS research paper on the Manus green tree snail and harnessing the Wisdom of the Crowd will be published in the international journal The Oryx later this year.