The tropical forest is home to a huge diversity of invertebrates
By Katie Doke Sawatzky on July 17, 2024
In the forest of Makira Natural Park in Madagascar, 16 scientists embarked on a three-week expedition to search for 30 lost species. Ornithologists, herpetologists, entomologists, arachnologists, ichthyologists and a primatologist set to work under tree canopies, on riverbanks, in streams and in the wet undergrowth of the rainforest floor.
“It was the first time we tried any kind of geographic large-scale lost species search,” says Christina Biggs, lost species officer for Re:wild. “Our typical model is to send a team to look for a specific species. This new approach felt large and it was somewhat unwieldy at times, but it also had a scope and reach that was incredible.
The search, which took place in August and September of 2023, was a collaboration between The Peregrine Fund’s Madagascar Project, Wildlife Conservation Society’s Madagascar Program, the University of Antananarivo, Biodiversity Inventory for Conservation (BINCO), Re:wild, and American Bird Conservancy. Scientists searched for lemurs, fish, various invertebrates, frogs and reptiles which have not had a documented sighting in at least a decade.
The search team travelled north of Maroantsetra, a district town on the northern end of Antongil Bay, in forest managed by Wildlife Conservation Society. Of the 30 species the team were searching for three were rediscovered, along with 18 others that were not originally on the team's list of species to search for. This included three fish species, five arachnids, a diving beetle, two ant-like flower beetles, two darkling beetles, and a millipede.
Dmitry Telnov, a beetle specialist with the Natural History Museum in London representing BINCO on the expedition, searched for invertebrates. His most exciting find was a 10.8-inch-long (27.5 centimeter) millipede, Spirostreptus sculptus.
“It was feeding on some plant debris, maybe on fungi,” says Telnov. “I photographed the specimen, thinking it would be well-known since it was so big.”
After sending the material to a German colleague specializing in Madagascan myriapods, the millipede turned out to be a species that had not been documented since 1897.
“It’s an amazing discovery that makes me happy because this species is not lost. It still persists in primary rainforest habitat and I observed several specimens, not just one,” he says.
The search team contended with strange weather conditions for most of the trip. It rained most days and the temperature was significantly cooler than normal.
“Basically, during these weather conditions, insects and most invertebrates are inactive because it feels like a tropical winter to them,” explains Telnov. “They hide. Some exceptions are mollusks or snails. For them, a wet climate is good. The mollusks were active, but insects weren't.”
Despite the challenging conditions, the sun came out on the last two days of the expedition and Telnov came away with other impressive findings. He recorded 27 beetle families, including the darkling beetle, Tamatasida tuberculosa, last reported in 1949 and first described in 1897 near Maroantsetra.
“There are hardly any natural habitats left near Maroantsetra itself,” he says. “It looks like Makira forest, which is some distance from the town and is a protected area with primary rainforest, [which] helps these species to survive in the area. This highlights the importance of protected areas for invertebrates, not only for big animals.”
Telnov observed a relative of the longhorn beetle, Nethinius longipennis, last seen in 1960, which he suspects also needs primary forest to thrive. He also observed two species of ant-like flower beetles, Sapintus mediodilatatus and Sapintus acuminatus, last described and reported in 1937 and 1958, both from a group he has studied for over 30 years.
“It was really, really interesting to find and observe them in nature myself,” he said.
Also keeping an eye out for mollusks, Telnov observed a tiny species of terrestrial snail, Kaliella crandalli. Found on the undersides of leaves on bushes or young trees, their shell is pyramid-shaped and less than an inch (25.4 millimeters) in diameter. It was first described by scientists 14 years ago.
“We observed five to 10 specimens so it appears to be a vital population in Makira forest,” he says.
While biodiversity remains rich in the protected forests of Makira Natural Park, Telnov and Biggs saw signs of human encroachment. Biggs noted that Madagascar’s rapid population growth puts pressure on the country’s east coast rainforests, some of which have been designated UNESCO Heritage sites since 2007.
“Major threats are deforestation and hunting pressure,” says Biggs.
Telnov recorded three species of highly invasive land snails from tropical Africa in Makira. They have spread around the world through human activity, he said, and may compete with native species for the limited amount of limestone in the forest, which snails require for their shells.
“Even if the human presence is limited in Makira forest, the presence of these species is alarming,” says Telnov.
Biggs notes that the search team did not see any fork-marked lemurs, which were last spotted in 2004. Not spotting large fauna after decades is usually a red flag for scientists, she says.
“It was concerning that we saw comparatively small lemur activity, pretty small, fractured groups that were isolated in habitat they couldn’t move around in.”
Overall Biggs celebrates the biodiversity and the rediscoveries the team made in Makira. Madagascar has several endemic species and Makira forest is considered a dark spot for biodiversity, in that little is known about many of the species that live there. After having been immersed in it for several weeks, Biggs says the idea of losing more rainforest would be “heartbreaking,” for the Malagasy people and the wider world.
“Madagascar is the most inspiring place. It has evolved critters that are almost unfathomable in their specific forms, with natural histories so beautiful, so rich, and so very, very threatened. It's an ecosystem on the brink of utter collapse,” she says.
Data from the trip will be shared with the International Union for the Conservation of Nature for that organization’s Red List of Threatened Species and with WCS, who manages the Makira protected area.
“It definitely does not do any good to have data if you are not sharing it,” says Biggs. “We were able to collaborate with WCS and support them. I think they've now been out a couple more times so that they can continue to build upon that data.”
Telnov said the search team worked well together, with each group of specialists searching in different places and at different times depending on the species they were looking for. He said some of his colleagues from other disciplines would pick up a “beetle, dragonfly, or snail on their way” for his research.
“It was a very good experience,” he says. “The team was good and really strong.”
Telnov relied on the generosity of the team in an unexpected way when his suitcase did not show up in Madagascar before the search team left for the forest. Borrowing some clothes, rubber boots, and tubes for specimens from his colleagues, he completed his observations without his own gear until two days before the team’s departure, when his suitcase showed up in the middle of Makira forest.
“I finally got some dry clothes to change,” he laughs. “If I had been alone, I would have not gone without my things, but with the team it was the right decision to go.”
The lost species expedition to Makira Natural Park was supported by the RIDGES Foundation.
Katie Doke Sawatzky
Katie Doke Sawatzky is a journalist originating from and living on the dwindling Canadian Prairie, in Treaty 4 territory and the homeland of the Métis. Her multimedia project prairiecommons.ca examined the state of native prairie in Saskatchewan, its biodiversity, and its public and spiritual value. She is based in Regina.