Length: Adults average 1,2 - 1,5 m with a maximum length of nearly 2 m
Colour variation is far greater than in any other South African snake. Juveniles are light grey to brown above with a fine stippling of blue, especially on the anterior parts. The head is brown to grey above, while the throat may be vivid yellow to orange. Below, white to yellowish woth dark specles. The enormous eyes are brilliant emerald green. When the snek is about 1 m long the colour changes to that of the adult
Most females are light to olive brown with dirty white to brown bellies, whereas males might have the following coloration: (a) green to olive green with or without black interstitial skin, the belly a similar but lighter colour; (b) bright green with black-edged scales, giving the snake a crossbarred appearance; (c) dark brown to black with bright yellow belly; (d) black above with dark grey belly scales that are black-edged. Brick red specimens are found in some areas.
There are also intermediates of these colours, and occasionally females have typical male coloration.
Similar species: Often confused with the black and green mambas (Dendroaspis spp.) and with the harmless green snakes of the genus Philothamnus.
Scale count: Midbody scales are in 19 rows (rarely 17 or 21), with 164-201 ventrals and 104-142 paired subcaudals. The anal shield is divided. There are 7 (rarely 6 or 8) upper labials, the 3rd and 4th (sometimes 4th and 5th) entering the eye, and 8-13 lower labials as well as 1 preocular (sometimes 2) and 3 (sometimes 2 or 4) postoculars. Temporals are 1 + 2, but variable.
Found in a variety of habitats throughout southern Africa including karoo scrub, arid savanna, moist savanna, lowland forest, grassland and fynbos. It is absent from much of the drier western parts of South Africa and is also not found on the central highveld and most of Lesotho
Predatory birds and other snakes. Birds such as bulbuls often mob it.
A notably unobtrusive, shy and diurnal snake that spends most of its time in trees and scrubs. It may also descend to the ground to hunt or bask, only to disappear into the leafy concealment of the closest scrub or tree when disturbed, where it is well camouflaged and difficult to detect.
Most of its hunting is domne in trees and scrubs, but it does descend to the ground to feed, especially along streams. With its superior vision, the boomslang has no difficulty in locating prey. When it does, it freezes with its head cocked, the only mevement being lateral waves that sweep the neck. It then swoops onto its prey, which is held firmly in its jaw while the fangs move with a chewing motion. The victim soon succumbs to the venom and is swallowed from the side, head first, or even from the back, if it is small enough.
If provoked, the boomslang will inflate the neck region to more than twice the normal size, displaying the vividly marked skin. Eventually the entire body is inflated, at which stage the snake will strike sideways and forward with a jerky motion. Most victims are snake park attendants or snake collectors. It is a widespread fallacy that the boomslang will drop from a tree onto anyone who risks walking beneath it, and then strikes the moment it makes contact.
Although the fangs are situated far back in the mouth, the boomslang can open its mouth as wide as 170 degrees and, contrary to popular belief, can easily deliver an effective bite on an arm or leg.
Reproduction: oviparous, usually laying 8-14, but as many as 27 eggs (27-53 x 18-37 mm) in hollow treetrunks, rotting logs or among leaf litter in late spring to mid-summer. The young measure 29-38 cm
Danger to man: Though its venom is deadly, this shy snake very seldom bites. Most victims have been snake handlers and park attendants.
Food and feeding
Actively hunts chameleons and other tree-living lizards, birds, nestlings, eggs (swallowed whole) and frogs. Small mammals are seldon taken.
Potently haemotoxic, causing severe internal bleeding and bleeding from the mucous membranes. May result in fatal haemorrhage if untreated. Although the venom is extremely potent, it is slow acting and may take more than 24-48 hours to produce serious symptoms.