Tag Archives: IUCN

Saving snails: an invasive species becomes an unlikely hero

A land snail (Photo/ Petr Kratochvil)

Now, I know snails don’t come with the same poster-child charisma factor of more fuzzy, wide-eyed creatures  like pandas or baby tigers. But I hope you’ll imagine a tiny, high-pitched, “Help me!” issuing from the leaf litter at your feet, and stick with these little guys for a minute.

With that said, I’d like to tell you a story of a rat, a snail and a tree. They all live on the tiny island of Anijima, one of several in a chain of islands off the southeastern coast of Japan. The snail is critically endangered. The rat and tree are invasive species. You know those bullies of the natural world, the unwelcome visitors, the home wreckers of entire ecosystems. But before you go, “Oh here comes another invasive species story,” here’s the kicker – one of these encroachers, the tree, is actually in a sense the hero of this story, buying time for the snail and those trying to save it. The study, published online in the journal Conservation Biology, offers conservationists a new framework for restoring native ecosystems.

Anijima is part of the Ogasawara Island chain, a remote group of islands off Japan nominated for World Heritage listing. It’s also snail central. These islands are home to more than 100 species of land snail, 94 percent of which are endemic to those islands. Many of the snails have disappeared over the years, thanks in part to habitat loss and introduced predators.

Anijima was the exception. No one has lived there since the 1830s, and until recently, the environment looked much like it did 100 years ago. But a plant, the Casuarina tree has taken over the mid-western part of the island, converting natural forestland into a monoculture of dry coniferous forest. This delivered a significant blow to the land snails, as the snail’s home was turned into less ideal living quarters. Another blow came with the introduction of black rats in the 1930s. These voracious predators, gobble up the slow-movers, and since about 2006, have enjoyed an unprecedented population boom on the island, likely due to the eradication of goats – a competitor for food – and of feral cats – the rat’s main predator. In short, things weren’t looking good for the snails.

One might think, “Well, if you want to save the snails, just go in there and clear out the invasives.” But not all invasive species are created equal, and one scientist, Satoshi Chiba, with Tohuku University in Japan, has figured out that the Casuarina tree is actually helping the snail weather the rat boom.

Chiba looked specifically at the Ogasawarana genus of snails, a critically endangered group of snails considered a “natural monument” by the Japanese government. They are the only group of snails on the island still living on native vegetation on the island. Chiba surveyed plots in both Casuarina-laden habitat and native habitat, clearing sites of leaf litter, counting and identifying snail species and then returning everything to its place. Chiba also checked for rat carnage, and found that while initially, the tree causes a decline in snail populations, once the rat population went crazy, the Casuarina tree actually provided the snail with a better refuge from the predator than the snail’s native habitat.

The ground litter in the Casuarina habitat is deeper and denser than the snails’ natural environment. Black rats like to forage at the surface, and thus, the snails stand a better chance of avoiding a rat’s tooth and claw in the debris of a Casuarina forest.

The lesson here is not that an invasive species is necessarily good, but that there is an order to things when it comes to restoring an environment impacted by multiple non-native species. For Anijima Island, and the Ogasawarana snails, if they are to be saved, it’s likely that the black rats need to go before the invasive trees.

So, do you care a little more about a tiny mollusk? I don’t know, but at the very least, the story has a rich history, and just think how many other species suffering from a similar tale this study could help.


WILD9 World Wilderness Congress: Different toolbox, same mission

Young Professionals and some of histories greatest conservationists gather at the Piedradeagua Hotel in Merida, Mexico, to enjoy some fine dining and discussions of how to conserve our planet. (Photo/Morgan Heim)

WILD9, thrusts you into a different world. Standing among so many of your heroes, legendary conservationists like Jane Goodall, and many of the world’s most renown conservation photographers can be an overwhelming experience, especially for a young professional. Everyone comes from a different background, science, conservation, communication, policy and business. Throw into that mix the intermingling of culture all around us, and it’s hard to know where to focus. And as any photographer can tell you, not knowing where to focus makes us just a little bit nervous.

But as the days pass, a transformation happens, and you start relating to each other as fellow human-beings with a common purpose. We are holding different parts of the puzzle and bringing it all together. We are participants. And after a few days, the mayhem begins to settle until you flow between roles and people and conversations.

Sasha, a young professional from Kamchatka, Russia jumps into a doorway to avoid streets flooded from the rains that hit Merida most likely in connection with Hurricane Ida.

I’ve been lucky. Much of this congress has focused on the role of conservation’s next generation. Of which, I am a part. I’ve had the opportunity to participate on panels, giving talks about how to use new media to further conservation messages. And work with the other young professionals on their media training day. It’s quite clear that we are here for a reason.

Last Tuesday night, many of the young professionals attended a special dinner in the ivy-walled gardens of the Piedradeagua Hotel in Merida. Fellow iLCP emerging league photographer Joe Riis was there, along with young professionals with veterinary backgrounds, community planning, and nature conservation management. And we found ourselves dining with the likes of Dr. Kenneth Miller, former Director General of the IUCN. To me this symbolized the culmination of our partnerships and the importance of meetings like the WILD9 World Wilderness Congress – a community of conservationists, each using a different toolbox, and spanning generations, but working together for the future.


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