Dasypeltis

African Egg-Eating Snakes

Introduction

Although most people will not know the name of these snakes, some may have seen pictures of them in books or on television. What makes them famous, of course, is their eye-catching habit of eating eggs (and only eggs). While most snakes can eat animate (albeit usually dead) prey larger than their own head, Dasypeltis can eat eggs that are likewise wider than their own girth. Shortly after swallowing, the egg forms an enormous egg-shaped bulge in the snake's body before the processes in the neck vertebrae break the shell. The snake derives its nutrition from the egg fluid, while the crushed shell is disgorged as a whole item. KKS note that some snakes do take prey eggs that are too large or inappropriate, causing death.

Apart from the vertebral processes that protrude into gullet, Dasypeltis are also characterised by very flexible skin, a pleated buccal membrane consisting of folds of gum tissue, and a very loose attachment between the scales and bones of the lower jaw. All of these are of course adaptations to their diet. The teeth are fairly rudimentary, so although these snakes may lash out if threatened, they strike to miss. Other characteristics are the blunt, bullet-shaped heads, the small eyes with vertical pupils, the strongly keeled body scales, and the absence of a loreal scale. As the teeth are so minimal, Dasypeltis depend instead on the mimicry (both colour-wise and behaviourally) of certain vipers in their range as a defence against predators. Since this can be fairly convincing, people approaching them in the wild should be certain that it is a Dasypeltis species and not a Bitis, Causus or Echis species before getting too close.

In nature Dasypeltis seek out the nests of smaller birds such as weaver-birds and tits. As birds eggs are seasonal, at least one of the species eats ravenously during spring and summer to lay down enough reserves for the rest of the year. It is important for anyone wishing to keep one of these snakes to have access to small and fertilised eggs rather than the typical chicken egg found in supermarkets. Erik Rundquist suggests finding a breeder of parakeets or finches and obtaining rejected eggs from them, the eggs being storeable in a fridge for some weeks. If kept properly, these can be long-lived pets: there is a captive record of 31 years for D. scabra.

All the species occur in Africa, although there is some debate over their number and definition: hence this listing may change in time. SHDA claim five species, Branch six. Identification by colour alone can be difficult as each species seems to have more than one phase.

	QUICK INDEX
D. atra, Montane Egg-Eater	D. fasciata, Western Forest Egg-Eater	D. inornata, Southern Brown Egg-Eater
D. medici, Rufous Egg-Eater	D. scabra, Common Egg-Eater

Species	Common Name	Origin	Adult size	Notes
Dasypeltis
D. atra	Montane Egg-Eater	Sudan, Kenya, Ethiopia, Tanzania, Uganda, Congo, Dem Rep Congo, Rwanda	Max 110cm, avg 50-80cm	Normally found above 1,500m in high-altitude savanna, grassland, woodland or forest (recorded range 1,000-2,800m). Scalation: 1-2 postoculars; body scalation strongly keeled and serrated, 22-27 rows at midbody, ventrals 202-237, subcaudals paired, 49-72. Coloration: SHDA list the following four phases: (a) uniform black all over, including ventrally, sometimes with grey throat (b) overall red-brown, red or pink, ventrally paler (c) uniform brown (d) brown with row of many darker blotches along the vertebral line; often white between blotches; faint dark lateral bars may be present; ventrally pale- or yellow-brown. Reproduction: in Uganda, egg-laying reported at various times of year. Female lays clutch of 7-14 eggs [SOURCE: SHDA]
D. fasciata	Western Forest Egg-Eater	W Uganda west to Gambia	Max 115cm; avg 50-80cm	Found in forest, moist and dry savanna, from sea level to over 2,000m. Scalation: body scales strongly keeled and serrated, 21-29 rows at midbody, ventrals 209-260, subcaudals paired, 64-68. Ugandan specimens have lower scale than more westerly specimens: see SHDA for details. Coloration: overall brown or yellow-brown, sometimes gerenish-brown; row of vertebral slightly dark saddles often present; slightly darker irregular lateral bars; ventrally yellow or light brown; supralabials may be dark edged; lowest 2 dorsal rows less prominently keeled and hence appear lighter; iris golden, or yellow heavily suffused with black. Reproduction: Ghanaian individuals known to lay 5-9 eggs [SOURCE: SHDA].
D. inornata	Southern Brown Egg-Easter	RSA (inc. KwaZulu-Natal and Swaziland)	Max (f) 89cm, (m) 78cm	Similar to D. scabra but with longer tail (69-92 subcaudals). Found mainly in open coastal woodland. Coloration: usually overall reddish-brown, sometimes yellowish-olive to dark brown: interstitial spaces are dark brown; ventrally white to dirty yellow. Reproduction: female lays 8-17 eggs in summer [SOURCE: Branch].
D. medici	Rufous/East African Egg-Eater	Kenya, Uganda and Zanzibar south to RSA, Malawi, Mozambique and E Zimbabwe	Max 1m: avg 50-80cm	Usually found in red soil areas: present in both coastal areas, hills and higher altitudes such as Mt Kilimanjaro. Scalation: body scales strongly keeled and serrated: see subspecies for more details. Coloration: variable, may be pink, orange, red, grey, fawn or brown: see subspecies for more details. Specimens with intermediate markings of both subspecies may occur in some areas. Reproduction: clutch size of 6-28 eggs [SOURCE: Branch, SHDA].
D. m. medici	Rufous/East African Egg-Eater			Scalation details: 23-27 rows at midbody, ventrals 235-259, subcaudals paired, 71-109. Coloration: darker vertebral line usually present about 5 scales wide, interrupted by white patches or spots; usually 3-7 distinct V-shapes on neck and narrow oblique lateral bars. Ventral coloration is paler and in southern Africa at least may have brown stippling. Lining of the mouth is pink.
D. m. lamuensis	Lamu Red Egg-Eater	Somalia into SE Kenya and Tanzania		Scalation details: 23-27 rows at midbody, ventrals 226-237, subcaudals paired, 71-109. Coloration: usually red, vivid pink or orange, but may be grey or blue-grey; sometimes fine white dot clusters along spine but no other markings apart from fine stippling (sometimes with white) on each scale.
D. scabra	Common/Rhombic Egg-Eater [F Rachiodon, Serpent mangeur d'oeufs: D Afrikanische Eierschlange]	SW Morocco, SW Arabia, sub-saharan Africa from Gambia and Senegal to RSA	Max 1.1m, avg 50-80cm	Found in a wide range of habitats and humidity levels from coastal forest to near-desert: not however above 2,600m altitude or in closed forest. It is a good swimmer and has colonised many Lake Victoria islands [SHDA], and often takes refuge in termite hills [KKS]. In appearance and warning behaviour it is rather similar to Echis pyramidum, hence care should be taken not to confuse the two. Branch also notes that western specimens imitate Bitis caudalis while specimens on the east coast imitate Causus species. Scalation details: rostral usually broader than deep; internasals somewhat shorter than prefrontals; no loreal; 1-2 preoculars, 2-3 postoculars; temporals 2+3 or 3+4, rarely 1+3; 6-8 (usually 7) supralabials, of which 3rd & 4th contact eye. Body scales strongly keeled and serrated, 20-27 rows at midbody, ventrals 180-263, subcaudals paired, 38-94. Coloration: variable; most commonly brown, reddish or grey with a vertebral row of darker oval or rhombic shapes, often interspersed with lighter blotches; often 1-2 V-shapes on the neck; flanks usually marked with fine irregular oblique darker bars; ventrals may be white or cream and either uniform or blotched to a certain degree. Other variations include unicolored individuals or individuals with faint patterns; overall coloration may be reddish or a shade of brown or grey. Lining of the mouth is black. Reproduction: females have larger body size but shorter tails than males, hence higher ventral scale counts but lower number of subcaudals: see KKS for details. 6-25 eggs laid per clutch: Branch cites hatching time of 80-90 days in South Africa in summer: in captivity two clutches per season may be laid [SOURCE: Branch, KKS, SHDA].

Bibliography

Amphibians and Reptiles of North Africa, W Kästle, H H Schleich and K Kabisch, Koeltz Scientific Books, Germany 1996. Includes details for D. scabra.

Field Guide to the Reptiles of East Africa by Stephen Spawls, Kim Howell, Robert Drewes and James Ashe, Academic Press London 2002.

Field Guide to Snakes and Other Reptiles of Southern Africa, Bill Branch, Struik, Capetown 1998.

Reptiles and Amphibians: Management in Captivity, Erik M Rundquist, TFH, New Jersey 1994.

Links

www.dasypeltis.com is dedicated to this interesting genus.

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