A scientific expedition to Angola’s remote Lisima plateau has uncovered dozens of species that were previously unknown to science.
Seen as one of Africa’s last great biodiversity blank spots, the in-depth exploration of the upper Cassai catchment area on Angola’s eastern plateau revealed eight undescribed dragonfly species, three new grasshopper species, and around 60 new moths and butterflies.
The findings, from the Cassai Life Atlas, a biodiversity survey conducted by The Wilderness Project in February 2026, provide a vital picture of the biodiversity across the Lisima landscape, which sits within the Angolan Highlands Water Tower in eastern Angola’s Moxico Province.
The vast area of miombo woodlands, wetlands, grasslands and source-lakes feeds four major African river systems: the Okavango, Zambezi, Congo, and Cuanza.
Water from the Lisima plateau sustains ecosystems and communities thousands of kilometres downstream, including the UNESCO-listed Okavango Delta.
Despite its ecological importance, decades of civil war, persistent landmines, and extreme remoteness left the region almost entirely uncharted by scientists.
The team of 16 African and international specialists, supported by Fundação Lisima and The HALO Trust, recorded 103 dragonfly and damselfly species, bringing the known total for the Lisima region to 163. Among them, 34 species hadn’t previously been recorded from Lisima, with six added to Angola’s national list. Eight undescribed species, first detected in 2019, are now being formally described.
Over 1,000 butterflies and moths were recorded, along with 47 grasshopper, katydid and cricket taxa, including three new to science. This number’s expected to increase, as many grasshopper and mantis specimens are still awaiting specialist examination. Beetles, spiders and scorpions were also collected, but results will also only be possible once specimens have been examined in the laboratory.
The herpetology survey recorded 24 amphibians and 23 reptiles, including the Gaboon adder, variable bush viper, Anchieta’s cobra, Oates’s twig snake, and an impressive collection of wetland frog species.
In caves, the team documented Sundevall’s roundleaf bat and Rüppell’s horseshoe bat.
The plant survey made more than 320 collections across miombo woodland, wet grassland, dambos, swamp forest, river margins, and rocky stream habitats.
“We expected the area to be diverse, based on our previous work in the Okavango and Lungwevungu catchments, where species turnover in the Angolan Miombo Woodlands is very high,” says Rob Taylor, the expedition leader and conservation ecologist.
“The most surprising finding was the strong Congolian forest influence in the upper Cassai catchment. The swamp forests and gallery forests changed our understanding of the area: it is not simply miombo woodland, but a complex transition zone between major habitats and biogeographic influences.
"The result of the survey was higher diversity than we anticipated. Abundances were often low, partly because these systems are nutrient-poor, but the diversity of specialised and unusual species was remarkable.”
By 2035, The Wilderness Project aims to study and help protect 1.2 million square kilometres of irreplaceable African freshwater wilderness, in partnership with local communities, governments, researchers and NGOs, including establishing detailed hydrological and ecological baselines of the largely undocumented sources and watersheds of Africa’s greatest river basins.
The Lisima region’s remoteness and the presence of minefields has previously limited human access and disturbance. But as road networks expand and mines are cleared, previously inaccessible areas are becoming increasingly vulnerable to human activities, such as diamond-mining, slash-and-burn agriculture, timber-harvesting, and associated settlement expansion.
Forest cover is being lost, rivers are becoming more cloudy through erosion and sedimentation, and natural habitats are becoming smaller, more fragmented, and increasingly isolated.
“The most important outcome of this expedition is that this area is no longer a blank spot,” says Taylor. “The species records, photographs and habitat data now provide evidence that can inform conservation-planning, land-use decisions and future protection.
"Previous biodiversity surveys in the upper Okavango and Lungwevungu catchments helped build the case for Ramsar recognition, Angola’s first Ramsar site. We hope the Cassai findings can make a similar contribution.
"There is urgency. The area’s already being affected by mining, clear-felling and woodland loss. The swamp forests and peat dambos [shallow, seasonal wetlands] are important carbon stores. Protecting these habitats would help conserve biodiversity, safeguard water systems and support broader conservation efforts around the Lisima landscape and the Angolan Highlands.”
In pictures: Lisima plateau discoveries
Top image: Undescribed crowned crab spider (Smodicinus sp. nov.). Credit: Nicky Bay | Courtesy of The Wilderness Project
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