Contributions to the herpetofauna of the Angolan Okavango-Cuando-Zambezi river drainages. Part 1: Serpentes (snakes)

The herpetofauna of Angola has been neglected for many years, but recent surveys have revealed previously unknown diversity and a consequent increase in the number of species recorded for the country. Most historical surveys focused on the north-eastern and south-western parts of the country, while mostly neglecting the central and south-eastern parts, comprising the provinces of Bie, Moxico, and Cuando Cubango. To address this sampling bias and investigate the conservation importance of the region, a series of rapid biodiversity surveys of the upper Cuito, Cubango, Cuando, Zambezi, and Cuanza river basins were conducted by the National Geographic Okavango Wilderness Project between 2015 and 2019. The first part of those survey results are presented here as an updated checklist of current and historical snake records from the south-eastern region of Angola. In summary, 160 new specimens were collected from the region, comprising 36 species, bringing the total number of recognized snake species for the region to 53. These surveys revealed three new country records (Amblyodipsas ventrimaculata, Crotaphopeltis barotseensis, and Dasypeltis confusa) and led to the description of two novel species in previous publications (Boaedon branchi and B. fradei), increasing the total number of snake species in Angola to 133. Finally, updated geographic distribution maps are provided for all species encountered in this study for the whole country. This contribution increases our knowledge of this poorly known region of Africa and highlights the need for and importance of similar studies in other undersampled areas.