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Snakebites in sub-Saharan Africa account for 20,000 to 32,000 annual deaths. But since most data is retrieved from hospital or incomplete central databases, and many victims do not seek hospital treatment or prefer traditional remedies, the current numbers are likely underestimated. In order to reduce snakebite incidence by 50% by 2030 as targeted by World Health Organization, it is crucial to accurately quantify and understand the current rates of snakebite incidence, which can only be reliably measured through household surveys. In this study, we interviewed 1037 households in nine communities in Cabo Delgado, northern Mozambique. Our aim was to quantify true snakebite incidence and under-reporting, by comparing the total number of snakebites reported to our team during household surveys with the subset of reports that reached health centers. We additionally quantified snakebite incidence in terms of species, location of the attack, type of treatment, season, and gender of the victims. These data allow us to propose conservative extrapolations of snakebite incidence and mortality for the province of Cabo Delgado and for Mozambique. Of all snakebites reported in the surveys (N = 296), most incidents were treated exclusively by traditional doctors (N = 174; 59%) and 25% were not seen by any doctor. Most bites occurred on farms and during the rainy season. Using a conservative estimation where we assume our results to be extrapolatable for the whole of rural Mozambique, but considering snakebites in urban areas to be inexistent, we propose that in Cabo Delgado, every year at least 6124 people are victims of snakebites, of which at least 791 result in deaths. In Mozambique, we extrapolated that every year at least 69,261 people are victims of snakebite, of which at least 8950 result in death (one in eight snakebites is fatal). Our estimates are the first for Mozambique based on data retrieved in the country, and despite being an underestimation they increase snakebite incidence levels ten-fold and the number of deaths by 30-fold. Urgent and widespread surveys are needed to further assess the full extent of snakebites in sub-Saharan Africa, explore regional patterns and develop mitigation plans.

Background Species with direct uses, such as sources of food, shelter, building material and medicine tend to have more specific local names. But could the same apply for species that people fear? Methods To address this question, here we explore the behavior and perception of species diversity and dangerousness through a survey of 1037 households in nine villages in Cabo Delgado, northern Mozambique. We compare people’s knowledge of snakes with that of lizards and amphibians. Results We find that northern Mozambicans know four to five times more local names for snakes than for lizards and frogs, despite the local species richness of snakes being comparable to the diversity of lizards and frogs. We further find that local knowledge was on par with the academic literature regarding snakebite symptoms. Conclusions Our results suggest that fear can increase the level of specificity in naming species among indigenous communities, which could lead to biases in the mapping and protection of species that include data from citizen reports.

A new species of tree snake Dipsadoboa montisilva Branch, Conradie & Tolley sp. nov. (Serpentes: Colubridae) is described from the ‘sky islands’ of Mount Mabu and Mount Ribáuè in northern Mozambique. Features of scalation, colour, body form and habitat distinguish the new species from other Dipsadoboa. This is supported by a phylogenetic analysis using one mitochondrial marker (cytochrome b) that shows the new Mozambican species is divergent from other sampled Dipsadoboa, including D. flavida and D. aulica, the only congeners known to occur in Mozambique. Morphologically, the new Dipsadoboa forms part of the D. werneri-shrevei complex from east and southeast Africa, but differs in having higher subcaudal counts, a different temporal pattern and only two supralabials entering the orbit. Phylogenetically, it occurs in a clade with D. shrevei and D. werneri. The status of D. shrevei in East Africa is reassessed, particularly in terms of the poorly-known Dipsadoboa shrevei kageleri from northern Tanzania. It is morphologically well defined from D. shrevei shrevei and utilises a different habitat. Although based on limited genetic data, it appears to be well-defined from typical D. shrevei and is accordingly raised to specific status. The only Tanzanian record for typical D. shrevei from Mtene, Rondo Plateau in southeast Tanzania is well isolated from the species’ range to the west (e.g. Zambia, Angola) and the published scalation features, particularly ventral counts, do not fully accord with D. shrevei. The Rondo Plateau population is treated as Dipsadoboa incerta sedis, and because we return D. shrevei to its binomial status, we can no longer consider D. shrevei as occurring in Tanzania. Biogeographically, the Rondo Plateau population may have a stronger affinity to the new Mozambican species. The discovery of isolated populations of the new species in mid-altitude forest remnants on Mt Mabu and Mt Ribáuè emphasizes the high conservation importance of the Mozambique forest ‘sky islands’ from which numerous other endemic new species have been recently discovered. These species are impacted by ongoing habitat destruction through slash and burn clearing for subsistence agriculture.