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SAHARA HORNED VIPERS
Saharan horned viper
Saharan horned vipers (Cerastes cerastes) are among the most common and easily recognized venomous snakes in North African and Middle Eastern deserts. They are also known as desert horned vipers, desert sidewinding horned vipers, North African horned vipers, African desert horned vipers, greater cerastes, asps and horned vipers and a number of local names. They are often easily distinguished from other snakes by the presence of a pair of "horns" above their eyes, although hornless individuals do occur as do ones with reduced horns. Three subspecies have been described. Wall Street Journal Wikipedia]
Sahara horned vipers range across North Africa, southwestern Arabia and parts of the Middle East, including Israel. They are common in the Sahara desert, and most frequently found in Egypt, Libya, Tunisia, Algeria and Morocco but are found southward into the Sahel in Mauritania, northern Mali, Niger, northern Chad and Sudan at elevations up to 1500 meters (4920 feet). They inhabits a variety of habitats within the desert: rock hills, sandy areas, wadis, and found in dunes, but are rarely found on rock pavement and gravel plains. The general distribution of Sahara horned vipers is strongly influenced microclimate. They generally prefer cooler temperatures, with annual averages of 20°C or lower. Humidity is important and temperatures must be high enough for the snake to bask and obtain heat, and humid enough to retain a maximum amount of water present in the body. Their only source of water is from prey. [Source: Issac Anderson, Animal Diversity Web (ADW) /=]
A number of subspecies of Sahara horned vipers have been described. They include:
1) Cerastes cerastes hoofieni (Werner & Sivan, 1999) in Saudi Arabia.
2) – Egyptian horned viper (Cerastes cerastes karlhartli) (Sochurek, 1974) in southeast Egypt and Sinai Peninsula.
3) Algerian horned viper (Cerastes cerastes mutila) (Domergue, 1901) in southwest Algeria and Morocco.
Previously Arabian horned vipers (C. gasperettii) were regarded as a subspecies of Sahara horned vipers but now is regarded as a separate species.
Sahara Horned Viper Characteristics
Compared to most snakes in their range,Sahara horned vipers are rather small. They range in length from 30 to 85 centimeters (11.8 to 33.5 inches), with their average length being 30 to 60 centimeters (11.8 to 23.6 inches), They are heterothermic (having a body temperature that fluctuates with the surrounding environment) and venomous. Sexual Dimorphism (differences between males and females) is present: Sexes look alike but females are larger. ales having larger heads and larger eyes than females. Their lifespan in captivity is 14 to 18 years. [Source: Issac Anderson, Animal Diversity Web (ADW) /=]
range of Saharan horned vipers
The head of Sahara horned vipers is somewhat flat, broad, and triangular, with eyes on the side of the head, and the neck is thin. The body is broad and appears flat, with a short tail which may have a black tip. They are generally brownish-yellow and gray in color, but can also be pinkish, or reddish or pale with their color almost always blending to the environment where they are found. Their undersides are white, On their back are semi-rectangular brown patches that are darker in color than the rest of the body and run the length of the body. These blotches may or may not be fused into crossbars.. The tail may have a black tip and is usually thin. They are covered in approximately 25 to 35 rows of heavily keeled scales, /=\
Sahara horned vipers are characterized by the presence of “horns” above they eyes, which consist of a single scale above each eye, from which a dark line extends towards the back of snake. This feature is generally what sets Sahara horned vipers apart from other species in the genus Cerastes. Arabian horned vipers (Cerastes gasperettii) have horns that consist of multiple scales, and Sahara sand viper (Cerastes vipera) have their eyes on the top of the head. The eyes of Sahara horned vipers are prominent and set on the sides of the head. Prominent brow ridges typically ensue the lack or reduction of these horns. /=\
Sahara Horned Viper Food, Hunting and Predators
Sahara horned vipers are carnivores (eat meat or animal parts) and mostly eat terrestrial vertebrates. Their diet consists primarily of small rodents, geckos, birds, and a variety of lizards. In captivity, adults have been observed feeding on weaver finches, lacertids (lizards), and dune geckos.These vipers are also known to eat jerboas (Lesser Egyptian jerboas), yellow wagtails (Motacilla flava thunbergi), and chiffchaffs (Phylloscopus collybita). [Source: Issac Anderson, Animal Diversity Web (ADW) /=]
Sahara horned vipers typically hunt by lying submerged in sand adjacent to rocks or under vegetation and ambush prey that comes within range. They have also been known to travel long distances at night in search of prey.When approached, they strike very rapidly, holding on to the captured prey until the venom takes effect. [Source: Wikipedia]
Known predators of Sahara horned vipers including honey badgers, monitor lizards, other snakes, feral cats and wild cats such as wildcats and sand cats. The coloring of Sahara horned vipers provides good camouflage, which helps both in avoiding predators and surprising prey. The burrows of Sahara horned vipers help them avoid extreme heat and predators and ambush unsuspecting prey. In the the eastern Sinai Sahara horned vipers coexist with Arabian horned vipers (Cerastes gasperettii).
Sahara Horned Viper Behavior and Movement
Saharan horned viper sidewinding
Sahara horned vipers are terricolous (live on the ground), fossorial (engaged in a burrowing life-style or behavior, and good at digging or burrowing), nocturnal (active at night), sedentary (remain in the same area), hibernate (the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal’s energy requirements) and solitary. They have a reasonably placid temperament, but if threatened, they may assume a C-shaped posture and rapidly rub their coils together. Because they have strongly keeled scales, this rubbing produces a rasping noise, similar to the sound produced by saw-scaled vipers. Hibernation occurs from January to February, but is interrupted by warm days. By late March, activity increases, and foraging mainly occurs at night. [Source: Issac Anderson, Animal Diversity Web (ADW) /=\; Wikipedia]
Sahara horned vipers are good at burrowing and burying themselves in the sand. Issac Anderson, wrote in Animal Diversity Web: Beginning at the posterior end, the snake extends its body anteriorly into the sand, usually until only its eyes and nostrils are exposed. During the day, it may hide in burrows or holes made by other animals, under wood or rocks, or even in bushes. It is most often found buried or partially buried in soft sand, avoiding the scorching heat as well as using its camouflage to capture potential prey. Sahara horned vipers are generally even-tempered snakes, but they are capable of administering toxic venom if threatened. When disturbed, the snake produces a hissing and crackling sound from the shaking and rubbing of its coils, and does so as a warning before striking. /=\
Sidewinding is the primary method of locomotion for Sahara horned vipers and the majority of desert snakes. This type of movement allows the snake to move quickly across the desert sands by lifting a loop of the body and moving it forward, while the rest of the body follows the moving loop. This also assists in preventing the snake from overheating, as minimum contact between the belly and the ground is maintained throughout the movement. When Sahara horned vipers move by sidewinding they press their weight into the sand or soil, leaving whole-body impressions. Often, it is even possible to use these impressions to make ventral scale counts. /=\
Sahara Horned Viper Senses and Communication
Saharan horned viper hidden under sand
Sahara horned vipers sense using vision, infrared light, touch, sound, vibrations and chemicals usually detected with smelling or smelling-like senses. They communicate with vision, sound and chemicals such as pheromones (chemicals released into air or water that are detected by and responded to by other animals of the same species). [Source: Issac Anderson, Animal Diversity Web (ADW) /=]
According to Animal Diversity Web: As specialized semi-fossorial snakes, all members of the genus Cerastes exhibit predatory launch strikes from partially buried positions in the Saharan sands. As such, the majority of the communication and perception techniques demonstrated by these snakes incorporate multiple environmental stimuli in order to enhance prey localization and acquisition. Through multiple studies and experiments, it has been found that foraging by vibration detection is particularly significant in Sahara horned vipers, as well as other members of the genus. Additionally, visual capabilities are pertinent in strike accuracy and distance, although the snake is still quite capable of capturing prey with hindered vision. Interestingly, prey capture behavior does not seem to be limited by olfactory senses, and in contrast to common belief, chemosensory reliance in Cerastes during foraging is nearly negligible, as visual stimuli act as primary determinants of prey apprehension./=\
When communicating with other members of its own species, Sahara horned vipers rely mostly upon chemical signals in the form of pheromones. This is used particularly during the mating season, as it acts to locate members of the opposite sex. Also, Sahara horned vipers makes use of vibrational stimuli and the ability to sense heat from other organisms in the environment from its pit organs in order to locate prey. Located just behind the nostrils, the pit organs in these snakes allow them to detect warm-blooded animals, even in the dark. /=\
Sahara Horned Viper Mating, Reproduction and Offspring
Sahara horned vipers are oviparous, meaning that young are hatched from eggs. They engage in seasonal breeding but their breeding interval is unknown. The breeding season is between April and June and eggs hatch from June to August. The gestation period ranges from 50 to 80 days. The number of offspring ranges from eight to 23. On average males and females reach sexual or reproductive maturity at two years.[Source: Issac Anderson, Animal Diversity Web (ADW) /=]
It is assumed that males and females locate and attract each other through the use of pheromones. Copulation is generally observed during the first week of April and always occurs while buried under the sand. In the case of two captive individuals, copulation lasted for four days.
Sahara horned vipers offspring develop outside the mother's body in the fertilized eggs she lays. An increase in oxygen consumption allows the snake to experience an exponential growth pattern throughout embryonic development, and normal respiration rates are assumed after hatching. Eggs are usually laid under rocks or in abandoned burrows of reptiles, or mammals. The young hatch after a 50 to 80 day incubation period. /=\
Sahara Horned Viper Venom and Bites
The bite of Sahara horned vipers causes swelling and tissue damage. The mortality rate is low and there is an antivenom. These snakes use venom to injure, catch and digest prey and as a means of defense when threatened. As is true with all three species of horned viper (Cerastes), the venom is mainly cytotoxic, affecting the walls and contents of cells, yet is not as toxic as the venom of other venomous snakes in their region. [Source: Issac Anderson, Animal Diversity Web (ADW) /=]
Sahara horned viper venom is reported to be similar in its affects to that of saw-scaled viper (genus Echis) venom. Bites usually causes swelling, nausea, hemorrhaging, vomiting, necrosis, and hematuria. A high phospholipase A2 content may cause cardiotoxicity and myotoxicity. Studies of venom from Sahara horned vipers and Sahara sand vipers list a total of eight venom fractions, the most powerful of which has haemorrhagic activity. Venom yields vary, with ranges of 19–27 milligrams to 100 milligrams of dried venom being reported. For venom toxicity, Brown (1973) gives LD50 values of 0.4 milligrams per kilogram IV and 3.0 milligrams per kilogramSC. An estimated lethal dose for humans is 40–50 milligrams. [Source: Wikipedia]
Despite their widespread distribution, Sahara horned vipers do not bite so many humans as a result of these snakes being relatively shy and non-aggressive and the fact most of them love on places where few humans live. Venom from Sahara horned vipers is being studied in connection with how certain enzymes affect on reptilian and mammalian biochemical processes, as well as in the production of antivenoms that are used for a variety of African snake species.
Sahara Horned Viper, Humans and Conservation
On the International Union for Conservation of Nature (IUCN) Red List Sahara horned vipers are listed as a species of Least Concern. In CITES (Convention on International Trade in Endangered Species of Wild) they have no special status. [Source: Issac Anderson, Animal Diversity Web (ADW) /=]
The primary threats to reptiles in general in the Sahara region are habitat loss and degradation, mainly due to human activities. Pollution, the introduction of alien species, and general human disturbance also have impacts.
As a very successful predator across the Sahara, Sahara horned vipers help control populations of rodents that disturb livestock and agricultural fields. In some areas, local people consider the snake to be relatively non-threatening and is even tolerated around some villages. In contrast, other places fear these snake, and believe they have magic powers and even can even fly. Some native snake charmers use Sahara horned vipers because of their horns. They have also been observed for sale at tourist resorts. /=\
Image Sources: Wikimedia Commons
Text Sources: Animal Diversity Web animaldiversity.org ; National Geographic, Live Science, Natural History magazine, CNTO (China National Tourism Administration) David Attenborough books, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Discover magazine, The New Yorker, Time, BBC, CNN, Reuters, Associated Press, AFP, Lonely Planet Guides, Wikipedia, The Guardian, Top Secret Animal Attack Files website and various books and other publications.
Last updated May 2025