Venomous Snakes of Mozambique

Mozambique is home to several cobra species. The black forest cobra (N. melanoleuca) is the largest species of African cobra, and sometimes approaches 9 feet in length. The forest cobra possesses very potent venom, and bites are sometimes fatal. The snouted cobra (Naja annulifera) is an attractive, banded species, formerly considered a subspecies of the Egyptian cobra (Naja haje). The Mozambique spitting cobra (Naja mossambica) is the only spitting cobra species found in Mozambique, and is capable of spitting venom up to 8 feet.

The longest venomous snake in Africa is the black mamba (Dendroaspis polylepis), which reaches nearly 10 feet in length. Highly aggressive when cornered or threatened, mambas will usually elect to flee if given the opportunity. Green mambas (D. angusticeps) are less aggressive than black mambas, but they're still highly venomous and demand caution.

The shield-nosed snake (Aspidelaps scutatus) is a small cobra-like species that spreads a narrow hood when confronted by a predator. Shield-nosed snakes use the modified scales of their noses to dig up frogs, toads and rodents. Three African garter snake species of the genus Elapsoidea occur in Mozambique; though they are venomous, bites -- like those of the shield-nosed snake -- are not usually life threatening.

Three members of the genus Causus inhabit Mozambique: the rhombic (C. rhombeatus), green (C. resimus) and snouted night adder (C. defilippii). Night adders are among the most primitive vipers, and they primarily consume frogs and toads. The bite of a night adder is generally not fatal, though it may hurt.

The infamous puff adder (Bitis ariens) ranges throughout Mozambique. Named for its loud hiss used to dissuade and intimidate would-be predators, the puff adder is an irritable species, with very large fangs and high venom yield. Additionally, Mozambique is home to two relatives of the puff adder: gaboon vipers (Bitis gabonica) and Cape Mountain adders (Bitis atropos). Though both are dangerously venomous snakes, and the gaboon viper’s 2-inch long fangs are the largest in the world, neither causes as many bites as their irascible relative.

Scientists recently discovered bush vipers (Atheris mabuensis) living in closed canopy forests of northern Mozambique. Swamp vipers (Proatheris superciliaris) are closely related to the bush vipers, but they live a terrestrial, rather than arboreal, lifestyle. Scientists doubt either of these vipers has a lethal bite, but as no antivenom is available, caution is appropriate.

Bibron’s stiletto snake (Atractaspis bibronii) is native to Mozambique. Stiletto snakes derive their name from their large fangs that move in a horizontal, rather than vertical, plane. Because of this, stiletto snakes can erect their fangs while their mouths remain closed. Stiletto snakebites are not usually life threatening, but they cause great pain.

Most colubrids are harmless to humans; however, recent evidence shows that most species have venom, but it's typically only effective on their prey. Nevertheless, three Mozambique colubrids do demand respect, including the boomslang (Dispholidus typus), the Cape twig snake (Thelotornis capensis) and the newly discovered Mozambique twig snake (Thelotornis mossambicanus). These snakes have powerful venom and grow large enough that a bite from one may result in an envenomation.