Boiruna

Boiruna is a small genus of New World snakes, with two species recognized in our database, including the False Mussurana (Boiruna maculata). These are large, robust, ground-dwelling snakes of South America, traditionally placed in the broad assemblage that older references call Colubridae. They belong to the pseudoboine group, the same lineage as the true mussuranas of the genus Clelia, which is why the common name carries the word mussurana. Adults are typically dark, often glossy black or steel-gray in mature animals, while juveniles can show a strikingly different banded or blotched pattern that fades with age.

These snakes occupy a range across southern and central South America, including parts of Argentina, Brazil, Bolivia, Paraguay, and Uruguay. They favor open and semi-open habitats such as savanna, grassland, scrub, and the edges of forest and farmland, and they spend much of their time on or near the ground. Like their mussurana relatives, they are best known as predators of other snakes, a habit called ophiophagy, and they subdue prey by constriction. Their broader diet can include lizards and small mammals, and they are egg-laying snakes.

Members of the pseudoboine group are rear-fanged, meaning they have enlarged grooved teeth toward the back of the upper jaw and a mild venom delivery suited to subduing prey rather than threatening people. They are not considered dangerous to humans and are generally regarded as harmless in normal encounters, though any wild snake can bite if handled. Because precise venom details for obscure species are not well documented, the safe practice is to leave wild snakes alone, never attempt to handle one, and treat any bite that causes a concerning reaction as a medical matter. In the United States contact Poison Control at 1-800-222-1222 or call local emergency services; elsewhere use your local emergency number.