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A giant dark brown millipede has been spotted in Makira National Park, home to the largest and most pristine forest in Madagascar. The species has not been documented for 126 years.
It is one of 21 “lost” species rediscovered by Re:wild during an expedition to the African island last September, the results of which have just been published. The conservation organization aims to locate species that have not been seen or recorded for at least 10 years, in the hope that by closing the data gap it can help prevent species from going extinct.
Christina Biggs, lost species officer for Re:wild, spotted the giant millipede crawling up her boot outside her tent one morning. “I filmed it for a while because I thought it was cool, with no idea that it was a real lost species,” she told CNN in an email. “It wasn’t until Dmitry Telnov, a beetle specialist at the Natural History Museum in London, sent footage to a German colleague who specialized in Madagascar millipedes that we learned it hadn’t been documented since 1897.”
The longest specimen of the species (scientific name: Spirostreptus sculptus) observed was a giant female measuring 27.5 centimetres (10.8 in). The team was surprised to discover that, despite a lack of scientific data, the millipede was actually quite common in the rainforest.
“There are so many reasons why a species hasn’t been documented in over a decade, or has been (lost) by our definition. Disease, pollution, catastrophic weather, human-wildlife conflict. But sometimes it’s just because people haven’t been looking for it or are less interested because it’s not fuzzy and cute,” Biggs said.
The other 20 rediscovered species included jumping spiders, ant-like flower beetles and three fish species. The team also documented new species that had never been recorded in Makira before, such as the zebra spider.
Brogan Pett, director of the SpiDiverse working group at the Biodiversity Inventory for Conservation (BINCO) and a PhD candidate at the University of Exeter in the UK, made the discovery after spotting a hanging egg sac in the entrance to a small cave.
“I immediately recognized them as something special,” he said in a press release. “Hanging egg sacs are one of the characteristics of the zebra spider family to which this new species belongs. I crawled a short distance into the cave and saw a few adult spiders guarding egg sacs – they were quite large spiders and it was remarkable that they had gone unnoticed for so long.”
In search of lost species
Biggs explains that when searching for lost species, Re:wild usually focuses on finding one or two species on a single expedition. However, due to the high biodiversity density in Madagascar, they took a different approach, with a team of 30 scientists from various universities and conservation groups specialising in a range of species.
However, some of the species they were looking for were not found, such as the Masoala pronghorn lemur, Calumma vatososa, a large chameleon, and the dusky tetraka, a small yellow songbird.
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Biggs fears this could mean some species are extinct. The country has seen extensive deforestation, with one study from 2023 estimates that Madagascar has lost 80 percent of its natural habitat. Although Makira is relatively intact, the team saw evidence of illegal mining, homesteading and rice paddies in the protected area, Biggs said. It also discovered several invasive species, such as mosquitofish, black rats and land snails, that could threaten native wildlife.
“We know that the larger a species is and the longer it has gone undetected, the greater the risk of extinction. So we’re concerned about the fork-marked lemur and the Fito leaf chameleon,” she said. The two species were last documented in 2004 and 2006 respectively, while the dusty tetraka was spotted by the Re:wild team in two other locations in Madagascar in 2022 and 2023, so they’re confident the species exists, but haven’t been able to confirm Makira as a habitat.
Biggs cautioned that the results come from “a single survey under very rainy conditions” and that “much more work is needed to conclude beyond reasonable doubt that the last individuals died.” The organization and its partners will continue expeditions to the island to collect more data.
“Effective conservation and protection efforts begin with understanding what species are present and where they are,” said Merlijn Jocque, a researcher at BINCO, in a press release. “Often this crucial information is missing, making it difficult to prioritize and implement effective conservation actions within limited resources.”
Biggs hopes that by identifying some of the 4,300 species worldwide that have not been documented for a decade or more, they can help protect vulnerable species and prevent extinction.
“You can’t save what you don’t know is there,” she said.
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