The Endodonta christenseni is small but mighty.
A tiny, endangered Hawaiian land snail found only in the native grasses of Nihoa, a tiny Northwestern Hawaiian Island that spans less than 180 acres, Endodonta christenseni’s role in the ecosystem and culture is much bigger than its small size would suggest.
Now, the Bishop Museum is working to save the species, and this weekend, the public will have the chance to see the snails up close.
A long history
C. Montague Cooke Jr., the museum’s first curator of mollusks, discovered the snail in 1924 during the Tanager Expedition, a series of five biological surveys conducted in the Northwestern Hawaiian Islands between 1923 and 1925, a recent announcement from the Bishop Museum notes.
But it wasn’t until 2020 that it was named by Bishop Museum curators Norine Yeung and Kenneth Hayes and their colleagues.
Descendants of the snails discovered more than a century ago, believed to be the last representatives of its genus, have this month made their way to the Bishop Museum’s Pūpū Ola: Kāhuli Captive Rearing Research Center.
Here, through a continued partnership between the museum and the state Department of Land and Natural Resources’ Snail Extinction Prevention Program, or DLNR SEPP, the snails will be protected, studied and bred to grow their numbers, before they’re eventually released back into the wild, the announcement noted.
There were once 11 species of Endodonta across the Hawaiian Islands, but today, the Endodonta christenseni is the only one that remains, Yeung said in the announcement.
“Along with a single surviving relative in the main Hawaiian Islands, Cookeconcha hystricella, these two species represent our last chance to save the ancient lineages of native land snails in Hawai‘i.”
About the snails
Biologically, the native land snails are detritivores, Yeung, malacology curator at the Bishop Museum, told Aloha State Daily.
“They are breaking down all of the animal and plant waste, breaking up all of the leaf litter, and they’re also then creating fertilizer and nutrition from their poop for our plants to have a healthy ecosystem,” Yeung says. They were also food for several native species.
But the snails also played a “huge role culturally,” appearing in mo‘olelo and oli, she said.
“Just think of them in Hawai‘i in particular like the farmers and the garbage men of the forest,” Kenneth Hayes, malacology curator and director of Pacific Center for Molecular Biodiversity explained. “Elsewhere in the world, snails tend to eat living plants, so they are pests in your gardens and things like that, but in Hawai‘i, they’ve adapted to not doing that but to helping plants grow in our native communities. That’s really tied to the maintenance and stability of [the] native ecosystem, which, in turn, is tied to the availability of water, which is a critical resource everywhere, but particularly in Hawai‘i, with very few other freshwater resources other than the clouds in the native forest.”
When asked about the significance of these specimens coming to Bishop Museum, Hayes told ASD that Hawaiian land snails are “incredibly diverse” but highly threatened, having faced some of the greatest rates of extinction because of habitat destruction and invasive species.
“We spent the last 20-plus years trying to figure out how many of the more than 759 species remain, where they are and then developing plans to try to conserve them, and one of the most effective tools we currently have in saving them is bringing them into protective rearing,” he says.
Hayes says the museum works with SEPP, the Honolulu Zoo and other partners to secure rare and endangered snails in protective rearing to better understand what the creatures need to survive.
“We can also bolster their population numbers by raising lots and lots of babies and then releasing them back out into the wild.”
As for Endodonta christenseni, Hayes says most recently a colleague from the state was able to make a trip to the island and got permission to collect some of the snails, which live in a “sort of unusual habitat that consists of the native grass and very little else.”
“It gets really dry there and there’s always the constant danger with increasing climate change of further droughts, but also fire from lightning strikes and things, so we wanted to safeguard a population of them just in case,” he explained. “He brought back a couple dozen and we’re now rearing them in captivity, both here and at the state facility.”
It's hard to know how many remain in the wild. Hayes estimates that on an island that size and in the kind of habitat they inhabit, there might be 1,000 or more. It seems like a lot, but not when you consider its size — the snail is less than five millimeters in diameter, he notes.
“It’s a pretty tiny little snail and their abundance used to be in the millions, so a few thousand at most is still a tiny population, especially when you consider that they have fairly short life cycles, but also, a whole population can be wiped out with just a small fire,” Hayes told ASD. “But they’re not really widespread, so it’s not really that many.”
Yeung shared a similar sentiment.
“Because it is endemic to this little tiny [island] of Nihoa, that if there were any hurricanes, tsunami or a fire … they’d be wiped out,” she said. “Once they are, being endemic to Nihoa, there won’t be any other place, not even on the main Hawaiian Islands, to find the species again, to put them back in the wild. It’ll be game over.”
By having these snails at Bishop Museum, Yeung says the hope is to learn as much as possible about the diversity of snails so that when additional snails are brought in, “we are able to figure out what they need to survive, but more importantly, when we put them back out into the wild, that we have a better understanding of some of the needs that they [have for] surviving outdoors.”
According to Bishop Museum, Hawaiian land snails are one of the most threatened groups of animals on Earth. The museum has the largest collection of Hawaiian land snails in the world, and has preserved specimens, DNA and tissues from thousands of species, many of which are extinct, the announcement noted.
Pūpū Ola, however, is the living complement to these collections.
Kāhuli Festival
Want to see Endodonta christenseni with your own eyes? The public can view these snails during Bishop Museum’s fourth annual Kāhuli Festival, which is 3 to 9 p.m. Saturday, Oct. 25. The theme of this year’s festival is Ke Kani Nei Ka Pūpū, “The Land Snails Sing.”
The campus-wide festival will offer cultural workshops and activities as well as talks from cultural practitioners, authors, researchers and conservationists; captive rearing exhibits with live endangered and rare snails from the museum’s Land Snail Conservation Program and DLNR SEPP; and art exhibits, food and drinks, music and more.
For the latest news of Hawai‘i, sign up here for our free Daily Edition newsletter.
Stephanie Salmons can be reached at stephanie@alohastatedaily.com.
