Eastern Green Mamba

The eastern green mamba (Dendroaspis angusticeps) is a highly venomous snake species of the mamba genus Dendroaspis native to the coastal regions of southern East Africa. First described by a Scottish surgeon and zoologist Andrew Smith in 1849, it has a slender build with bright green upperparts and yellow-green underparts. The adult female averages around 2.0 metres (6.6 ft) in length, and the male is slightly smaller.

Eastern green mamba is a large snake, with a slightly compressed and very slender body with a medium to long tapering tail. Adult males average around 1.8 metres (5 ft 11 in) in total length, while females average 2.0 metres (6 ft 7 in) in total length. This species rarely exceeds lengths of 2.5 metres (8 ft 2 in). In general, the total length is 4 - 4.3 times the length of the tail. The adult eastern green mamba has bright green upperparts occasionally with isolated yellow scales and a pale yellow-green belly. Sometimes they are duller-coloured before moulting. Juveniles are blue-green, becoming bright green when they are around 75 centimetres (2 ft 6 in) long.

The coffin-shaped head is long and slender, with a prominent canthus which is slightly demarcated from the neck. When threatened or otherwise aroused, the eastern green mamba is capable of flattening its neck area, though no real hood is formed.

This species is not commonly found on the ground unless motivated by thirst, prey, or the need to bask in the sun thermoregulation. It is an adept climber and an extremely agile snake. It sleeps at night in a tree coiled up in leafy clumps rather than seeking a tree hollow (although sometimes found in them). In a study of the movement patterns of two adult specimens of this species over a 27-day period, the researcher found their activity range areas to be very low, comparable to other predators who ambush prey rather than actively hunt. This is in contrast to most elapid species, including other mambas, who tend to actively hunt or forage for prey. The study's preliminary evidence sheds some light on this species' method of hunting prey and suggests that it may be an ambush predator due to the sit-and-wait behaviour displayed.

This mamba preys primarily on birds and their eggs as well as small mammals including bats. It is believed that this species eats arboreal lizards as well. This species uses a sit-and-wait strategy of foraging, though an eastern green mamba has been recorded actively hunting sleeping bats. The species has also been known to raid the nests of young birds.

Although it generally avoids people, the eastern green mamba is a highly venomous snake. The peak period for bites is the species' breeding season from September to February, during which mambas are most irritable. A survey in southern Africa from 1957 to 1979 recorded 2553 venomous snakebites, 17 of which were confirmed as being from eastern green mambas. Of these 17 cases, 10 had symptoms of systemic envenomation, though none died. The snake tends to bite repeatedly, so there can be multiple puncture wounds. A bite can contain 60–95 mg of venom by dry weight. The subcutaneous murine median lethal dose (LD50) is 1.3 mg/kg. The LD50 in mice through the IV route is 0.45 mg/kg.

The eastern green mamba's venom consists of both neurotoxins and cardiotoxins. Symptoms of envenomation include swelling of the bite site, dizziness and nausea, accompanied by difficulty breathing and swallowing, irregular heartbeat and convulsions progressing to respiratory paralysis. Bites that produce severe envenomation can be rapidly fatal.