''Dasypeltis scabra'', also known commonly as the common egg eater, the egg-eating snake, and the rhombic egg eater, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

snake Snakes are elongated limbless reptiles of the suborder Serpentes (). Cladistically squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales much like other members of the group. Many species of snakes have s ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Colubridae Colubridae (, commonly known as colubrids , from , 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest fossil species of the family date back to the Late Eocene epoch, with earlier origins suspected. C ...

. The species is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

Africa Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...

Geographic range

''D. scabra'' is found in

sub-Saharan Africa Sub-Saharan Africa is the area and regions of the continent of Africa that lie south of the Sahara. These include Central Africa, East Africa, Southern Africa, and West Africa. Geopolitically, in addition to the list of sovereign states and ...

Description

''D. scabra'' grows to a total length (tail included) of , and has almost toothless jaws.

Dorsally Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

, it has a series of

rhomboidal Traditionally, in two-dimensional geometry, a rhomboid is a parallelogram in which adjacent sides are of unequal lengths and angles are non-right angled. The terms "rhomboid" and "parallelogram" are often erroneously conflated with each oth ...

dark brown spots on a lighter background. There is an alternating series of brown spots on each side and a distinct V-shaped mark at the back of the neck. Ventrally it is yellowish, either uniform or with dark dots.

Mimicry

It has been suggested that non-venomous ''D. scabra'' is a

mimic In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simples ...

venomous Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

Echis carinatus ''Echis carinatus'', known as the Sindh saw-scaled viper, saw-scaled viper,Mallow D, Ludwig D, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. 359 pp. . Indian sa ...

'', the saw-scaled viper, which it strongly resembles. Typical specimens of ''D. scabra'' even more closely resemble ''

Causus rhombeatus ''Causus rhombeatus'', commonly known as the rhombic night adder, is a species of venomous snake in the subfamily Viperinae of the family Viperidae. The species is native to Sub-Saharan Africa. No subspecies are recognized as being valid. Des ...

'', the rhombic night adder. The colouration of ''E. carinatus'' generally tends to be more reddish and brown, instead of shades of grey and black; and the V-shaped mark on its head is more patchy than in the other two species. ''C. rhombeatus'' is not as slim as ''D. scabra'', and its

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

, unusual among viperids, are at most slightly keeled, whereas ''D. scabra'' scales not only are keeled, but in some parts of the body are finely saw-toothed so that, when an alarmed snake rubs them against each other, they emit a threatening hissing sound. The species does not hiss in the usual manner at all. Both species typically have well-defined V-shaped markings on the head and neck, but in ''C. rhombeatus'' the marking extends forward on the head, whereas in ''D. scabra'' it is mainly on the neck. Furthermore, the two species also may be distinguished by the shape of the pupil of the eye. Snakes of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

Dasypeltis ''Dasypeltis'' is a genus of snakes, also known commonly as egg-eating snakes or egg-eaters, in the subfamily Colubrinae of the family Colubridae. The genus is one of only two taxonomic groups of snakes known to have adapted to feed exclusive ...

'' have vertically slitted pupils, whereas snakes of the genus ''

Causus ''Causus'' is a genus of Viperidae, vipers found only in sub-Saharan Africa. It is a group considered to be among the most primitive members of the family Viperidae based on head scalation, oviparity, venom apparatus, and because they have round ...

'' have round pupils. However, in dim light the vertical pupils expand till they are rounded, so this is not necessarily a reliable criterion for distinguishing the species.

Habitat

''D. scabra'' can be found in a variety of

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s, at altitudes from sea level to . It is not found in closed-canopy

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

s nor in true

desert A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...

s, but does inhabit most ecosystems between these extremes.

Behavior

The rhombic egg eater is

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

. Although mainly

terrestrial Terrestrial refers to things related to land or the planet Earth, as opposed to extraterrestrial. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on o ...

, it is a good climber and is known to scale rock outcroppings and climb trees to raid birds' nests.

Diet

''D. scabra'' feeds exclusively on eggs. The lining of the mouth has small, parallel ridges, very similar to human fingerprints, which aid in grasping the shell of an egg. Once swallowed, the egg is punctured by specialized vertebral hypapophyses which extend into the esophagus. The shell is then regurgitated in one piece, and its contents passed along to the stomach.

Defense

When disturbed, ''D. scabra'' inflates itself, "hisses" by rapidly rubbing together the rough, keeled scales on the sides of its body, and strikes with its mouth kept wide open. Gans, Carl; Richmond, Neil D. (1957). "Warning Behavior in Snakes of the Genus ''Dasypeltis'' ". ''Copeia'' 1957 (4): 269-274.

Reproduction

''D. scabra'' is

oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...

. In summer, a sexually mature female may lay one or two

clutches A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does the ...

of 6–25 eggs each. The eggs measure . Hatchlings are in total length. Branch, Bill (2004). ''Field Guide to Snakes and other Reptiles of Southern Africa''. Third Revised edition, Second impression. Sanibel Island, Florida: Ralph Curtis Books. 399 pp. . (''Dasypeltis scabra'', pp. 95–96 + Plate 15).