Viper, African Bush


Atheris squamigera


Grows to an average length of 18 – 23.6 in (46-60 cm), with a maximum of at least 30.7 in (78 cm). Females are usually larger than males. The head is broad and flat, distinct from the neck. The mouth has a very large gape. The head is thickly covered with keeled, imbricate scales. The rostral scale is not visible from above. A very small scale just above the rostral is flanked by very large scales on either side. The nostrils are lateral. The coloration is the same in some populations, but variable in others. The dorsal color varies from sage green or light green to green, dark green, bluish, olive or dark olive brown. Rare specimens may be found that are yellow, reddish or slate gray. The scales have light-colored keels and sometimes yellow tips that form a series of 30 or more light crossbands or chevrons. On the tail, there are 10-19 chevrons: not always clearly defined, but usually present. The ventral edge of the dorsum has light spots in pairs. An interstitial black color is visible only when the skin is stretched. The belly is yellow or dull to pale olive; it may be uniform in color, or heavily mottled with blackish spots. The throat is sometimes yellow. The tail has a conspicuous ivory white tip, 0.25 – 0.5 in (7-12 mm) long.  Neonates have a dark, olive coloration with wavy bars, paler olive or yellowish olive with fine dark olive margins, bars at 0.19 in (5 mm) intervals, and a belly that is paler greenish olive. The adult color-pattern develops within 3 to 4 months.

Family

Viperidae

Order

Squamata

Class

Reptilia

Range

West and Central Africa: Ivory Coast and Ghana, eastward through southern Nigeria to Cameroon, southern Central African Republic, Gabon, Congo, DR Congo, northern Angola, Uganda, Tanzania (Rumanika Game Reserve), western Kenya and Bioko Island.

Habitat

Rainforest, but prefers relatively low and thick, flowering bushes

Life Expectancy

10 – 12 years in captivity

Sexual Maturity

About 2 - 3 years

Diet

In the wild, they eat primarily rodents; in the Zoo they are fed mice.

Status

Not Listed

Behaviors

During the daytime it can be found up in the vegetation, while in some investigated populations it moves down toward the ground at night to hunt. Mating takes place in October, and the live young are born during March and April. The clutch size is about seven to nine young.

Adaptions

All vipers are solenoglyphous. Solenoglyphs have completely enclosed hollow fangs attached to the maxillary bone. These fangs, which are replaced periodically throughout the snake’s life, are folded into cavities in the roof of the closed mouth and may be erected simultaneously, individually, or not at all during a strike. A strike is more of a stab than a bite, and venom may or may not be injected. The venom is primarily hemotoxic, affecting the blood. Reported symptoms of Atheris bites include pain, swelling, and blood clotting difficulties. Blood transfusions may be required if poor blood clotting occurs. Bush vipers are often found in isolated populations far removed from humans and therefore cause very few snakebites. Their venom is poorly studied and there is no available antivenin. Existing antivenins do not neutralize the venom of this genus. However, there is some anecdotal and unconfirmed information that polyvalent Echis serum has been used with success in Atheris squamigera.

Special Interests

Other common names include: green bush viper, variable bush viper, leaf viper, common bush viper, bush viper, rough-scaled bush viper and tree viper. The species name squamigera is Latin for “scale-bearing” and is derived from squama (scale) and the feminine suffix –gera (carrying or bearing). A number of subspecies may be encountered in literature. These include: A. s. squamigera (Laurent, 1956), found in Ghana to Cameroon, DR Congo, Uganda, western Kenya and Angola A. s. robusta (Laurent, 1956), from the Ituri Forest in Province Orientale (DR Congo); it is sometimes described as growing larger, having a lower subcaudal count and only a single row of scales between the eye and the upper labials. A. s. anisolepis (Mocquard, 1887), found in West Central Africa: Gabon, Congo, west DR Congo, north Angola.

Folklore

Conservation

Jacksonville Zoo History

The Jacksonville Zoo is one of only 5 AZA accredited zoos in the country exhibiting this species.

Exhibit

Seronera Reptile House