Amsterdam zoo helps threatened Polynesian snails

Two Polynesian tree snails, photo by Artis, Ronald van Weeren

Translated from Dutch daily Algemeen Dagblad today:

Artis [zoo in Amsterdam] is committed to preserve endangered Polynesian tree snails. Amsterdam’s zoo is breeding snails in their Insectarium. After the breeding they will go back to their natural habitat on the island group in the Pacific.

Things go badly for the native snails in French Polynesia, of which Tahiti is the most famous island. The arrival of a carnivorous snail species made certain species of tree snails extinct, while those are important for the biodiversity of the tropical islands. In the Insectarium of Artis are 687 tree snails of three Tahitian species.


Saving Polynesian snails in London

This video from Scotland is about Partula snails.

From Wildlife Extra:

Near extinct snails bred at ZSL London Zoo to be released back into the wild

Tiny endangered tree-snails to be reintroduced onto Tahiti

September 2013. Hundreds of tiny endangered tree-snails will be reintroduced to their former Polynesian home following the incredible success of an international breeding programme led by ZSL London Zoo.

30 year absence

Three species of Partula snail, Partula affinis, Partula nodosa, and Partula hyalina, which were bred at ZSL London Zoo and other partner zoos around the world, will be released on to the island of Tahiti in October after a nearly 30 year absence.

ZSL London Zoo invertebrate keeper and coordinator of the international Partula studbook, Don McFarlane, along with staff from Bristol and Edinburgh Zoos, will be escorting the precious cargo of snails to Tahiti, where they will be released into a protected reserve in their native forest habitat.

McFarlane said: “We’re incredibly proud of the role ZSL London Zoo has played in bringing these snails back from the brink of extinction and reintroducing them to their native Tahiti. There used to be more than 70 species of Partula tree snails across the Pacific French Polynesian islands, but due to man’s influence, most of these species are now endangered or extinct in the wild.

“This project is the result of almost 30 years of collaborative work between zoos around the world, and the French Polynesian Government. We’re really hopeful that the hard work will pay off and we’ll see Partula snails thriving in the wild once again.”

Driven to extinction by Wolf snail

Originating from the steep volcanic forested islands of French Polynesia, Partula snails provide valuable insights into the mechanisms of evolution. Populations of the snails were decimated after the predatory rosy wolf snail (Euglandina rosea) was introduced from Florida in the 1970s to rid the islands of a previously-introduced alien species – the African giant land snail – but the rapacious predator devoured the tiny native snails instead.

The Partula Global Species Management Programme is coordinated by ZSL London Zoo with St Louis Zoo, and combines the breeding programme for 16 species in 16 different zoos around the world with field conservation work in the Polynesian islands.

This video from the USA says about itself:

Extinct Snail and Its Baby!

4 February 2011

The Partula snail is extinct in the wild. But a small population hangs on as part of a breeding program at Seattle’s Woodland Park Zoo. This short clip shows how the snail moves. A baby snail can be seen next to the adult.

First Polynesian humans discovery

This video says about itself:

“The last great human migration: DNA and the human settlement of the Pacific” (Part 1)

Professor Lisa Matisoo Smith, University of Otago, New Zealand.

Friday 13 May 2011

Over the last thirty years there has been a fundamental change in our knowledge of the human settlement of the remote Pacific, the last major region of the Earth to be colonised by people.

The story begins with the Neolithic expansion out of Asia via Taiwan, through Island Southeast Asia and Near Oceania and out into Remote Oceania. In the Pacific, this migration event is associated archaeologically with the appearance and spread of the Lapita Cultural Complex (about 3500 to 2000 years ago) and linguistically with the distribution of Austronesian languages. The final stage of this migration was the settlement of the Polynesian Triangle (demarcated by Hawaii, Easter Island and New Zealand).

While this so called “Fast Train Model” has, for the most part, been rejected by the archaeological community, this general story of the migration of a population making its way out of Taiwan and purposefully sailing through Near Oceania to the islands of Polynesia has captured the public imagination. Genetic research has also contributed to this story with the identification of molecular markers that appear to track this migration event — in particular the distribution of the mitochondrial DNA marker known as the “Polynesian motif”. But as more genetic data accumulate this simple model appears to be problematic.

This lecture will discuss the latest genetic studies that suggest a more complicated picture of Pacific settlement and population origins and show how ancient DNA analyses are allowing us to test some possible alternative scenarios for the settlement of the Pacific islands and beyond.

From Simon Fraser University in Canada:

Scientists improve dating of early human settlement

15 Nov 2012

A Simon Fraser University archaeologist and his colleagues at the University of Queensland in Australia have significantly narrowed down the time frame during which the last major chapter in human colonization, the Polynesian triangle, occurred.

SFU professor David Burley, Marshall Weisler and Jian-Xin Zhao argue the first boats arrived between 880 and 896 BC. The 16-year window is far smaller than the previous radiocarbon-dated estimate of 178 years between 2,789 and 2,947 years ago.

Burley, the lead author, and his colleagues have recently had their claims published in an article in the open access journal PLOS ONE.

Polynesia, a group of 1,000 islands forming a geographic triangle connecting Hawaii, New Zealand and Easter Island in the South Pacific Ocean, is one of the last landscapes discovered and settled by humans.

Burley’s team applied uranium/thorium dating to a series of coral artifacts recovered from a site in Tonga known to be the first settlement location for Polynesia.

This dating technique is not new, having been used previously to date coral reefs and stalagmites in caves and other materials. But this study’s authors had to develop new processes and verification protocols to achieve their more precise dating of the Tongan artifacts.

When the results came back from a Queensland University lab, Burley says his only comment was: “Wow! It is spooky that we can track an event that happened so long ago to such an exact period of time.”

The researchers dated coral files, common day artifacts used to file-down wood or shell materials for manufacturing other artifacts. Thirteen of these were successfully dated, all nicely falling into a temporal sequence from top to bottom of their archaeological siting.

Burley is most excited about a coral file found in the very bottom of the site. Not only does it have the oldest date, but also it was found in beach sand, over which the archaeological site formed. “It is the beach on which first landfall took place, and we now know exactly when that happened,” says Burley.

Polynesian people used binary numbers 600 years ago: here.

Saving Henderson Island’s birds

From BirdLife:

Aircraft carrier and helicopters come to unique island’s rescue

Tue, Dec 20, 2011

A ground-breaking $2.3million RSPB (BirdLife in the UK) project to eliminate introduced rats from an uninhabited island in the central Pacific has attempted to remove the fingerprints of man from an otherwise idyllic tropical paradise. As a bonus, the project has also increased the known size of the UK’s overseas territories by six square kilometres.

Henderson Island, one of the UK’s most remote territories and a World Heritage Site, has been ravaged by Pacific Rats, introduced by the Polynesians eight centuries ago. The rats were destroying the island’s habitats, driving the Endangered Henderson Petrel Pterodroma atrata towards extinction, and significantly damaging the populations of four other bird species, rare plants, insects and snails all found nowhere else on earth. There were millions of ground-nesting seabirds on Henderson before rats were introduced to the island, but their numbers have been reduced to just 40,000 pairs today. Early results indicate that the seabird population will boom if the rats have been successfully removed.

The mission – a partnership with the Pitcairn Islands Government – was one of the most complicated the RSPB has ever undertaken, and involved a voyage of 27,000 kilometres in a purpose-built aircraft carrier, capable of handling two helicopters from its temporary flight deck. It hopes to have removed introduced rats from Henderson Island by dropping poison rat pellets from giant hoppers suspended beneath the choppers with sufficient accuracy to land a few feet apart across the entire island.

Covering 43 square kilometres, Henderson Island is over 3,000 miles from the nearest mainland in South America. It is the world’s only forested atoll with its ecology virtually intact, and the largest tropical or sub-tropical island ever subject to a rat eradication attempt. Although the results won’t be known until 2013 – when rat surveyors visit the island – the RSPB remains extremely hopeful that the project has eradicated rats from the island, as no previous aerial operation to remove Pacific rats has failed.

Non-native species, such as rats, have been one of the greatest drivers of extinction of birds, especially on remote islands where the native wildlife has evolved in isolation away from predatory mammals. Although it’s too late for some now-extinct species, the RSPB hopes that the project has thrown Henderson Island’s unique wildlife a lifeline, including four species of landbird found nowhere else on earth: a fruit-dove; a lorikeet; a reed-warbler and a rail: a relative of moorhens and coots.

See also here.