Herpetology of Ethiopia and Eritrea

Our records => Viperidae, Oppel 1811

Bitis arietans Merrem 1820

Very large viper, largest in Africa. The average size is about 1m, and very stout. Large is specimens of 190 cm total length, weighing over 6.0 kg and with a girth of 40 cm have been reported (Bitis arietans somalica). The nostrils on the upper side of the nose. Dorsal scales strongly keeled, 29 - 41 midbody scale rows, In Ethiopia average 29 - 35, ventrals 129 - 149 and subcaudals 23-30 (in females 13 - 21). The body fat, tail short.
The keels in the somali Bitis arietans are always most strongly developed distally, becoming progressively less distinct proximally, and there is individual and sexual variation in the number of subcaudals that bear keels. Females clearly have the character more developed than males and in the latter sex there are indications that there may be progressive reduction with increasing size (age) [According to PARKER].
FMNH specimens from Nairoby, Kenya; Cuma, Angola: Midbody scale-rows 29-35; ventrals 129-137; anal entire; subcaudals 14-28; labials 12-15. Largest specimen measures 839 (780+59) mm [LOVERIDGE].

Bitis arietans is thought to be the most common and widespread snake in Africa, occurring throughout the continent except in some forested regions and extreme deserts such as the Sahara. This species also occurs in Yemen and southwestern Saudi Arabia. In Ethiopia at whole teritory at lower altitudes.

This species is a primarily nocturnal ambush predator, preying on small mammals, birds, lizards, frogs, and toads, and while it spends most of its time on the ground, it can also swim or climb into low vegetation. It is generally slow-moving, but it can strike extremely quickly. Viviparous. Female give birth youngs. In Ethiopia, occur both subspecies, B.arietans arietans (west and north) and B.arietans somalica (south and east).

Description original:
Merrem, B.: Versuch eines Systems der Amphibien I (Tentamen Systematis Amphibiorum). J. C. Kriegeri, Marburg, 191 pp.

Common english name: Puff Adder

Bitis arietans somalica - habitat, Dire Dawa, E Ethiopia

Bitis parviocula B烺ME 1976

Short description:
The head is long, flat, triangular and covered with small, strongly keeled scales. The nostrils are large and set well forward. The head is distinct from the thin neck. The body is cylindrical with a slight vertebral ridge, while the tail is short. The dorsal scales are keeled and are arranged in 37-39 rows at midbody. The color pattern consists of a light brown to dark brown ground color, overlaid with a series of black hexagons or diamonds that run down the center of the back. The black hexagons may have paler crossbars, while being separated from each other by a chain of yellow butterfly shapes. A series of black triangular or subtriangular spots, each with a white center, run down the upper flanks. The lower flanks have a series of greenish-gray triangles, pointing upwards, with yellow edges, especially the tips. The flanks between these triangles are a mottled green color. The head is brown with a dark triangle between the eyes and a dark hammer shape just behind it that extends onto the nape of the neck. The iris is brown. The side of the head is dark, but with a pale stripe that runs from the eye down to the labials. The upper labial scales are white. The chin and throat are white with black speckling. The belly is greenish-gray and may be clear, or with black speckling.

The endemic species of Ethiopia. The type locality is bridge over the Doki river near the village Yayo at altitude 1800 - 1900 m asl. Other sites of occurrence are around Bedelle, Bonga and Jimma. Probably whole southwest highland on suitable forested areas. .

It inhabit forested areas west of the Rift Valley. Some specimens, was caught in a forest clearing in an old coffee plantation, while the other was found in a forest town, hiding in grass of the grounds of a Bedelle brewery [Lizler].

B鐬me,W.: Eine neue Art der Gattung Bitis (Serpentes, viperidae) aus 礫hiopien. Monitore zool. ital. (N.S.) Suppl. 9 (3): 59-68

Common english name: Ethiopian Mountains adder

Bitis parviocula - type locality, Yayo, Illubabor, W Ethiopia

Bitis harenna GOWER et al. 2016

Short description:
Head posteriorly much wider than anteriormost end of body (neck). Distance between snout tip and posterior end of retroarticular process 43.7 mm (longitudinal distance between level of these two points 42.5 mm). Eyes surrounded by 12,15 circumorbital scales; separated from supralabials by 2 to 3 scales; pupil vertically eliptical. Left and right circumorbital series separated by at least 10 interorbital scales. Nostrils broadly oval (anteroventrally-posterodorsally oriented). Supranasal shields overhang nasals substantially, separated middorsally minimally by 2 scales, separated from circumorbitals minimally by 2 scales. Nasals and supranasals separated from rostral by 3,3 scales (> 3 mm), from first supralabial by 2,3 scales (2.5+ mm). Rostral much wider (5 mm) than high (2.1 mm at midline). Most dorsal and lateral head scales between and behind eyes keeled except supralabials and adjacent row posterior to 9th or 10th supralabial; no keels on scales of lower jaw or chin. Posteriormost left and right supralabials separated by at least 31 scales. Supralabials 14,14. Infralabials 15,17, last of which especially small on each side; first pair contact at midline, second to fifth contact genials. Mental triangular, wider (5.1 mm) than long (3.3 mm). First pair of genials largest, contact at midline; second pair of genials much smaller and separated by one pair of smaller gulars; first pair of genials separated from first preventral by four gulars. First ventral separated from last infralabial by 8,7 scales. Inside of mouth without pigment (except for at least tips of tongue, dark). Teeth mostly hidden in gingivae. Left fang intact, approximately 11.6 mm long. Keels on body scales moderate, most prominent on dorsum, less prominent on lower than upper flanks, absent on first dorsal scale row; where prominent, keels extend to distal tip of scales; posterior margins of scales entire (not notched). Difficult to determine presence or absence of apical pits; seemingly present in at least some dorsal body scales, paired, close to scale tips. All scales on tail keeled except for subcaudals. [According to GOWER et al.].

The endemic species of Ethiopia. Forested areas in the Bale mountains, central Ethiopia. Dodola, south to Harenna forest. Probably other forested areas on the eastern side of Rift Valley.

Description original:
GOWER, DAVID J.; EDWARD O. Z. WADE, STEPHEN SPAWLS, WOLFGANG B烺ME, EVAN R. BUECHLEY, DANIEL SYKES, TIMOTHY J. COLSTON 2016. A new large species of Bitis Gray, 1842 (Serpentes: Viperidae) from the Bale Mountains of Ethiopia Zootaxa 4093 (1): 041063

Common english name: Bale Mountains adder

Causus maculatus HALLOWELL 1842

Causus maculatus - Gambella, Ethiopia
Causus maculatus - Gambella, Ethiopia

A small snake, reaches up to 60 cm. Midbody scale rows 17-22, ventrals 118-154, subcaudals 15-26, higher numbers are valid for males (in Ethiopian specimens Mbr 19, ventrals 134-137 in females and 139-150 in males; subcaudals 20-22 in males and 17-20 in females).
The head is small, slightly fattened above, depressed in front, covered with nine plates; the rostral plate is rather large, pyramidal, rounded in front, its apex projecting backwards; the frontonasal are irregular in shape, the posterior and external angle beng prolonged to meet the loreal plate; its inferior curved, to form the upper margin of the nostril; the frontals are irregularly quadrilateral; the vertical plate is hexagonal, its lateral margin being slightly excavated where it joins the supraorbital plate; the occipital are small, pentagonal; the supraorbital are oblong, quadrilateral, projecting but slightly over the eye; the lateral and inferior margin of the orbit is bordered by a row of five or six plates; of these, the two anterior are the smallest; the nasal plates are two in number; the nostrils are large; there are six superior labial plates; of these, the second is the smallest; the fourth the largest; the fangs are small; the tongue is long, enclosed in a sheath at its base, bifid at its extremity; the body is brownish or ash-colored above, (in spirits) with numerous dark colored lines and spots upon the sides; there is a series of dark colored bands upon the middle line of the body, having the form of chevrons bordered with white; a large triangular blotch. exists upon the head, extending a short distance along the neck, resembling in shape an arrow head; the throat, abdomen, and under part of tail, are silvery white he scales upon the back are carinated; the carime upon the sides are much less distinct than those upon the back, presenting the appearance rather of elevated points in the centre of each scale; many of the scales are perfectly smooth; the tail is short; there are two small fangs in the upper jaw. Abdom.scut.120; subcaud. 23eighteen of which, or those nearest the anus, are bifid; the remaining five, at the extremity of the tail, being entire [According to HALLOWELL].

Mauritania, Senegal, Gambia, Mali, Burkina Faso, Niger, Chad, Central African Republic, W Ethiopia, Uganda, S Sudan, Ivory Coast, Cameroon, Democratic Republic of the Congo (Zaire; except in the east), Congo (Brazzaville), Ghana, Togo, Benin, Guinea, Nigeria, Gabon, Sierra Leone.
In Ethiopia, the western part of the Rift Valley (Gambella, Omo Valley, Asosa, Blue Nile Valley).

Description original:
Hallowell, E.: Description of a new genus of Serpents from Western Africa. J. Acad. nat. Sci. Philadelph. 8: 336-338

Common english name: West-African Night Adder

Causus maculatus - habitat, Gambella, Illubabor keflehager, W Ethiopia

Causus resimus PETERS 1862

Short description:
A small snake, maximum length up to 80 cm, in average 50 - 60 cm. The rostral shield slightly raised. The head relativelly small, little distingt from the body. Eye big, pupil rounded. The tail 7 - 9% of the total length in female, 8 - 10% in males. Dorsal scales keeled. Midbody scale rows 19 - 21, ventrals 131 - 154, subcaudals 15 - 25. Coloration velvety green in different shades. Throat yellowish or cream as belly.
Scales in 23 rows, only those of the upper series on the hinder part of the body are keeled. The rostral shield is turned upwards, with a slightly swollen upper edge as in Causus rostratus, in which, however, the shield is still more prominent. In other respects the scutellation is very much as in the other two species. The anterior frontals are a little longer than the posterior, and the area of the vertical shield considerably surpasses that of the occipital. Nostril between the two nasals and the anterior frontal. Loreal square; orbit surrounded by a ring of small and narrow scutes. Six upper labials; temporals 2+3, the two anterior being the largest. Ventral scutes 146. The coloration of the adult is uniform greenish olive, the abdomen being whitish. A very young specimen has the back crossed by numerous narrow curved bands, the convexity being directed backwards. The neck and occiput are ornamented by the outlines of the arrow-shaped spot which is observed in the two other species, but which in this species is lost in the adult [According to G逴THER 1888, as Causus jacksonii].
FMNH specimen from Angola: Midbody scale-rows 21; ventrals 142; anal entire; subcaudals 20; labials 7. Total length 496 (450+46) mm [LOVERIDGE].

Sudan, Ethiopia, Somalia, Kenya, Uganda, Tanzania, Mozambique, Malawi, Zambia, Rwanda, Burundi, N/E Democratic Republic of the Congo (Zaire), Chad, Cameroon, Central African Republic, Nigeria.
In Ethiopia rarer than the other two species. Southwest Ethiopia from the Omo basin to the west to South Sudan (Gambella), south of Rift Valley (Arba Minch).

They prefers low-lying moist savanna, wooded hills, high grasslands, and the riparian zones of rivers that run through swamps, rocky gorges, coastal scrubland and semi-deserts. If disturbed, they inflate themselves and put on a ferocious hissing and puffing threat display. The front part of the body is raised and coiled from which position they tend to make sweeping and lashing strikes as opposed to a stabbing motion. They are mostly terrestrial, but are also good swimmers and have been known to climb into sedges in pursuit of prey. Despite their common name, they are diurnal and are often seen basking. They hide under ground cover when not active.

Description original:
Peters,W.C.H.: 鈁er die von dem so frh in Afrika verstorbenen Freiherrn von Barnim und Dr. Hartmann auf ihrer Reise durch Aegypten, Nubien und dem Senn漷 gesammelten Amphibien. Monatsber. Akad. Wiss. Berlin 1862: 271-279

Common english name: Green Night Adder

Causus rhombeatus LICHTENSTEIN 1823

Short description:
A medium snake, maximum length up to 100 cm, average 60 cm, the head relativelly small, little distingt from the body. Pupil rounded. The tail short 9 - 12% of total length. Dorsal scales keeled. Midbody scale rows 15 - 23 (Ethiopia 17 - 20), ventrals 134 - 166 (Ehiopia 146 - 166), subcaudals 21 - 35 (Ethiopia 20 - 28). Color gray, gray-brown or brown, rarely olive green. On the dorsum 20 - 30 dark brown, white bordered blotches. Small darker spots on the flanks. At the top of the head characteristic dark Λ blotch.
Mid-body scale rows, 17 to 19; ventrals, 143 to 156; anals, entire; subcaudals, 21 to 26; labials, 6, usually the fifth the largest but sometimes the third or fourth; temporals 2+3 (2 +4)Snout obtuse or but slightly prominent ; midbody scale-rows 1720; ventrals 138145; anal entire; subcaudals 17-20, mostly paired (Torit-South Sudan; 0424′29″N 3234′30″E)
FMNH specimens: Midbody scale-rows 17-18; ventrals 140-155; anal entire; subcaudals 22-33; labials 6. Largest specimen measures 674 (607+67) mm. The latter is the Nairobi specimen most unfortunately referred to resimus by Meek who gave its tail length as 17 instead of 67 mm., its midbody scale-rows as 17 instead of 18, and its ventral count as 161 instead of 155 [According to LOVERIDGE].
[According to LOVERIDGE].

Angola, Republic of South Africa, Natal, Swaziland, Democratic Republic of the Congo (Zaire), Sudan, Ethiopia, Somalia, Botswana, Zambia, Zimbabwe, Mozambique, Tanzania, Rwanda, Burundi, Uganda, Malawi, Kenya, Congo, Cameroon, Central African Republic, Equatorial Guinea, Nigeria, Namibia.
It is remarkable that this species, so widely distributed and so common throughout the Savannah regions of Africa, appears to be confined to the western uplands in the Somali region and to be relatively uncommon. The Ethiopian region is its extreme northern limit in the east of Africa and it may be that it is a recent immigrant along the higher lands in which there are permanent streams; stresses the close association of the species with water.

Oligophagous. They feed mainly frogs, most often toads. Females lays 10 - 30 eggs in size 30 x 20 mm. Incubation period 60 - 90 days.

Lichtenstein, M. HINRICH C.: Verzeichniss der Doubletten des zoologischen Museums der K霵igl. Universit酹 zu Berlin nebst Beschreibung vieler bisher unbekannter Arten von S酳gethieren, V鐷eln, Amphibien und Fischen. K霵igl. Preuss. Akad. Wiss./ T. Trautwein, Berlin. x, 118 pages

Common english name: Rhombic Night Adder

Causus rhombeatus - habitat, Chencha, Gamo Gofa keflehager, S Ethiopia

Echis - komplex

Echis pyramidum pyramidum (GEOFFROY SAINT-HILAIRE, 1827) - A medium-sized snake, with a short, stocky body. Largest Egyptian specimen has a total length of 649 mm (Schmidt & Marx 1957). Tail short, tail / total length = 0.09-0.11. 10-13 supralabials; eye moderate, separated from supralabials by 2-3 scales, pupil vertical; scales on dorsal side of head rather large, 9-12 interorbitals; dorsals strongly keeled, 27-31 scale rows around mid-body; 167-186 ventrals, 31-38 single subcaudals; anal entire (Anderson 1898, Schmidt & Marx 1957, Baha El Din unpub. data.). Dorsum grey, with a mid-dorsal series of dark-edged, whitish, narrow saddles, interspersed with large dark brown-grey blotches; a lateral series of smaller dark spots; dorsal side of head with a dark arrow-like mark (often broken); indistinct dark, diagonal band below the eye. Venter white [According to BAHA EL DIN].
Snout short, broad and rounded, its length less than the anterior interorbital breadth; rostral very much broader than high ; nasal generally divided, in contact with rostral and first labial, and usually a small supranasal, separated from the second labial by a single scale ; a supraocular sometimes present; eyes separated above by from 10 to 15 scales; 11 to 20 scales around the eye, and two or three scales between it and the upper labials; 10 to 12 upper labials, exceptionally 9 or 13. One pair of chin-shields in contact with three or four labials, followed by two to five pairs either of small square shields or scales. 25 to 37 rows of scales across the body; 132-195 ventrals; anal 1 ; subcaudals 23-48. The upper surface generally dark brown or some tint of brown, with 36 to 40 irregular whitish, yellowish, or greyish-yellow transverse bands of varying breadth, more or less dilated in the mesial line, and uniting with one another on the sides, thus defining off a lateral line of more or less triangular dark brown areas, each alternate with the dark brown areas of the back ; the front line of dorsal scales more or less spotted with black ; head generally brown, with a varying number of yellowish or greyish-yellow bands, reducing the brown colour to a well-defined, almost black band behind the eye, a spot below the eye, and to a few irregular bands, lines, or spots on the upper surface of the head, sometimes assuming the form of cruciform markings. Under surface white, with some black spots on the angles of the ventrals and some indistinct spots on the mesial line ; on the subcaudals the spots tend to arrange themselves as a median longitudinal band or line [According to ANDERSON].

Common english name: North-East African Carpet Viper or Saw-scaled Viper.

Echis pyramidum leakey - habitat, east shore of Chew Bahr lake, S Ethiopia
Echis cf.varia - habitat, Awash NP, E Shewa, C Ethiopia

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