A Gaboon Viper

Vipers are snakes belonging to the family Viperidae, made of hundreds of species that can be found in all but the coldest climates. The viper is native to every continent except for Australia and Antarctica. The name comes from the Latin words “vivo” and “pario,” together meaning “live birth.” There are a few species who lay eggs, but vipers primarily give birth to live babies.

What unique features do these reptiles have?

Vipers have a wide head and long, hollow fangs that are attached to rotating joint bones called “maxilla.” Normally, the fangs are folded into membrane sheaths when the mouth is closed. When attacking, the maxilla fold the fangs down, and the mouth can open almost 180 degrees. When making a defensive strike, the snake merely stabs its adversary with the fangs and pulls back. However, when hunting prey, this stabbing is followed by a strong bite, pushing the fangs in further. While most poisonous reptiles release all of their venom at once, vipers can inject a precisely-controlled dose into its victim. The amount of venom injected varies depending on threat level, size of the victim, and whether the victim is held or let go by the snake.

Most species have “keeled” scales, with a thick ridge running through the middle of each plate. While most snakes use smooth keeled scales for traction, vipers have serrated edges on their ridges. When threatened, the snake can rub these scales together to make a loud scratching sound, in much the same way a cricket rubs its legs together to chirp.

The Viperidae Family can be divided into three major subfamilies:

Crotalinae subfamily
Common name: Pit Viper

This is the largest subfamily, made up of 151 species including rattlesnakes. The name comes from the snake’s pits, a pair of heat sensitive organs between the nostrils and the eyes of these snakes. Found across Europe, Asia, and the Americas, these reptiles mostly prefer to stay in cool areas, using ambush techniques to hunt at night.

Causinae subfamily
Common name: Night Adder

Despite their name, these snakes will hunt day or night. They have venom glands that can be as long as three inches (10 cm) running down the neck. The Night Adder rarely uses venom, preferring to hunt by biting and swallowing its prey, typically frogs, whole. When prey is abundant, the Adder has been known to eat so much it is physically unable to swallow. This subfamily is only found in sub-Saharan Africa.

Azemiopinae subfamily
Common name: Fea’s Viper

The Azemiops feae is the only species known in this subfamily, and it’s the only viper without keeled scales. When threatened, it puffs out its jaws and flattens its body against the ground to make it look larger. The snake can be found in the mountains of Vietnam, China, Tibet and Myanmar.

A King Cobra

The name “cobra” is derived from the Portuguese “cobra capo,” literally “snake hood.” This term can refer to any hooded snake, regardless of taxonomy. Most of these snakes are in the Elapidae family, but because the term is so general almost 300 species fall into this category. Although they’re closely identified with a threatening head thrusting pose, this ability isn’t universal for these reptiles. The category can be divided into six major groups of animals:

Ophiophagus hannah
Common name: King Cobra

The largest and most famous of all cobras, this species can reach a length of over 18 feet (5.5 meters.) The Ophiophagus hannah can pull its body upward like the Naja, and its hiss sounds like a growling dog. Although it doesn’t have the strongest venom, each bite dispenses enough poison to kill an elephant. It is also the only snake that builds a nest for its eggs, guarding them until they hatch. It can be found in southeast Asia, India and southern China.

Genus Naja
Common name: Typical Cobra 

This group of twenty or so species is what most people think of as a cobra. When threatened, a Naja snake can pull as much as one quarter of its body upright and flatten its neck, creating the pose most associated with these snakes. The Naja naja is revered in India, and is the reptile of choice for snake charmers. Other examples of the genus can be found throughout Africa and Asia.

Genus Aspidelaps
Common name: Shield Nose or Cape Coral snake

The African A. lubricus and A. scutatus are similar to Naja species aside from a smaller hood.

Genus Pseudohaje
Common name: Tree cobras

Originally thought to be in the Naja genus, these tree dwellers were reclassified once it was discovered that their venom used a different type of neurotoxin. Found in Africa, these tree dwellers have smaller fangs and bone structure than snakes in their former classification.

Hemachatus haemachatus
Common name: Ring-necked Spitting Cobras, Rinkhals

Another South African snake, it is one of the few species known to play dead when it senses a threat. When attacking, the Rinkhals aims at the face of the threat: Its venom can be extremely painful if it comes in contact with the eyes. Mothers carry their eggs until the hatch.

Micrurus fulvius
Common name: American Cobra or Eastern Coral Snake

Found in the Southeast of the United States and parts of Mexico, this snake lacks a hood. The harmless Scarlet Snake and Scarlet King Snake mimic the Micrurus fulvius’ red and yellow coloring.

Hydrodynastes gigas
Common name: False Water Cobras, Brazilian Smooth Snake

This South American snake can climb, burrow and swim, letting it travel through any terrain. Fortunately, bites are rare and its venom has almost no effect on humans.

Genus Bitis
Common name: Puff Adder

These species of venomous vipers in Africa and the southern end of the Arabian Peninsula. Their common name comes from their ability to inflate and deflate their entire bodies, giving them a distinct hissing pattern.

A Pewter Ball Python

Python is a genus of snake that is often confused with the boa, with which they share several physical traits; Several snake species have been classified under both groups at one time or another. Although both hunt by constricting prey, boas give live birth and lack heat-sensing pits.

The python’s natural habitat is in Sub-Saharan Africa and much of Central and Southeast Asia, although the snakes have also become an invasive species in North America. Pythons are non-venomous, killing their prey by constricting around them. Attacks on people are extremely rare, and despite numerous myths, it’s very rare for pythons to actually eat a human. The snakes can swallow prey equal to its body weight and up to 25% of its length.

Today, there are seven recognized species of python:

P. regius – Ball or Royal

This Sub-Saharan snake grows to only 3 to 4 feet (1 to 1.3 meters) in length. This small size makes them popular pets. The name “ball” comes from their habit of curling up into a ball when stressed, while “royal” stems from a legend that one was kept by Cleopatra.

P. anchietae – Angolan

Closely related to the Ball python, this snake is found in southern Angola and northern Namibia. It can reach a length of up to 6 feet (2 meters.)

P. curtus – Short-tailed

Found throughout Southeast Asia, these snakes are hunted for their red and tan skins which are used in leather production.

P. molurus – Indian or Black-tailed

Although an excellent swimmer, this snake is lethargic, and will stay still even while being attacked. Desired for its skin and meat, populations have been pushed down to a point that they are protected in some areas.

The bivittatus subspecies, known as the Burmese Python, has become an invasive species in Florida. Ideally suited to life in the state’s wetlands, these animals have been able to breed in the wild. The population is estimated to be over 30,000 state-wide, with at least 5,000 living inside the Everglades National Park. Although they pose little threat to humans, this snake is an indiscriminate eater that poses a serious threat to endangered wildlife. Unaware that the species can reach lengths between 14 and 20 feet (4.5 to 7 meters,) owners would release these reptiles into the while once they were too large to care for.

P. reticulatus – Reticulated

Found throughout Southeast Asia and the surrounding islands, it’s the longest known snake with specimens reaching a length of 20 to 30 feet (7 to 10 meters.)

P. sebae – African Rock

With subspecies found across West and Central Africa, these snakes can easily top 20 feet (7 meters) in length. They have no problem going after large prey, and have been known to eat antelope.

P. timoriensis – Timor

Despite the name, this small snake has been found throughout much Southeast Asia, except the island of Timor. Females will coil around their eggs, keeping the brood warm and protected until they hatch.

An Inland Taipan aka The Fierce Snake

Taipans belong to the Oxyuranus genus. Currently, there are three known species of this Australian snake: Inland (Oxyuranus microlepidotus,) Coastal (Oxyuranus scutellatus,) and Central Ranges (Oxyuranus temporalis.) These snakes subsist mainly on rats, followed by birds, lizards and smaller marsupials. Most adults reach a length of 8 or 9 feet (2.5 to 3 meters.)

Inland Taipans have the most powerful land snake venom known to man, with the other varieties following close behind. This venom acts both as a neurotoxin and as a powerful blood clotting agent, rapidly destroying the cardiovascular system. Until an antivenom was developed, bites from the snake were always lethal. Even today with proper medical treatment, victims must be hospitalized for some time before they recover completely.

Taipans are often compared to Africa’s Black Mamba. as both snakes like to live in sugar cane fields, and they both hunt using stealth, getting a swift venom injection into an animal and waiting for it to die before feeding. However, the Australian snake is far less dangerous than its cousin, as it is only found in the most remote areas and prefers to slither away when provoked. Although there’s an average of around 40,000 deaths due to snake bites each year, this Australian species is only responsible for two or three of these. In the past eight years, all confirmed bites from the Inland variety have happened to herpetologists (snake scientists,) and each time the bite was successfully treated with antivenom.

Ironically, this shy behavior makes these snakes difficult to study. The Central Ranges Taipan is a recent discovery, with the just two examples having been found since it was identified in 2007.

The widely feared Black Mamba

Black Mambas are known to the scientific community as “Dendroaspis polylepis.” A native of eastern Africa, the snake can be found in a wide range of habitats, including grasslands, forests and swamps. Most of these reptiles grow to a length between 8 and 10 feet (2.5 to 3 meters) and weigh around 12 lbs. (5.5 kg.) They subsist on a diet of birds, small mammals, and other snakes.

The snake’s venom contains dendrotoxins, a class of neurotoxin unique to Black Mambas. Once in the bloodstream, these toxins block potassium channels inside neurons, preventing nerves from activating muscle tissue. This venom is the fastest acting of any known snake species: Without swift antivenom treatment, a poisoned bite is guaranteed to cause death by cardiac arrest, often within an hour of the attack.

When hunting, the snake will quickly crawl up to an animal, pause long enough that the prey loses interest in any motion it may have detected. The snake will inject poison on the first strike, and wait for it to slow down the victim’s movements. If the animal is still active, the snake will finish it off with a quick succession of non-venomous strikes. The Mamba will then wait for the venom to take full effect before eating the now dead animal.

Most attacks on humans occur on sugar plantations where the snakes like to climb on top of the cane to sun themselves. When threatened, the snake will not hesitate to make multiple strikes. Killing a Black Mamba can be exceedingly difficult, as they have very quick reactions and have been known to crawl along the ground at speeds up to 14 mph, faster than any other land snake in the world.

The Death Adder aka The Copper Head

Although the term is sometimes applied to Agkistrodon contortrix (commonly called Copperheads,) the term “Death Adder” is mainly applied to snakes in the Acanthophis genus. Scientists do not have a single consensus on the taxonomy of these animals, with three generally accepted species plus four possible species. At least seven other possible Death Adder species have been reclassified as subspecies. Examples of these reptiles can be found in Australia, Papau New Guinea, and Indonesia. The length of adult reptiles ranges from 24 to 39 inches (60 to 90 cm,) with females being considerably smaller than males.

These snakes don’t actively hunt. Instead, they will bury themselves in soil or leaves, leaving only the head and tail exposed. The snake lures prey by wiggling the end of the tail, tricking the hapless animal into thinking it has found a worm or grub. Adders have been known to stay in place for days waiting for the next meal to be drawn in by this ploy. Unsurprisingly, most bites occur when a hapless human steps on a disguised snake.

Death Adders produce a venom that is neurotoxic, with bites causing paralysis and, after several hours, full respiratory shut-down in humans. Until an antivenom was developed, nearly half of the bites from these snakes were lethal. In the future, this venom may be used to save lives: It acts by blocking acetylcholine, a neurotransmitter known to be a factor in Alzheimer’s disease. Those suffering from the disease have reduced numbers of receptors to absorb acetylcholine, and it’s believed that compounds in the venom could restore the nervous system’s chemical balance.

A Western Diamond Back Rattlesnake

Rattlesnakes are part of the pit viper family, with thirty-two known species grouped in the Sistrurus and Crotalus genera. These snakes can be found throughout the Americas, from western Canada south to Argentina. Although mostly concentrated in the deserts of the American Southwest and northern Mexico, the snakes have been found at altitudes as high as 10,000 feet. In adulthood, most species reach a length of 3 to 4 feet (1 to 1.3 meters.)

Like copperheads and cottonmouths, rattlesnakes have heat sensing organs called “pits” between their eyes and nostrils. These are so accurate that the snake can identify the size and distance of warm-blooded prey, allowing it to hunt in total darkness. Rattlesnakes mostly prey on rodents and small birds.

The rattle is made out of hollow segments made of keratin, the same material that makes up hair and nails. This is attached to special fast firing muscles that can shake the segments together as fast as fifty times per second. The snake will add a rattle each time it sheds its skin, but this isn’t an accurate predictor of age: Shedding is dependent on how much the snake is able to eat, and its normal for rattles to break off from time to time.

The rattlesnake is the leading cause of poisonous reptile bites in North America, and a major cause of bites in Central and South America. However, they’re known only to bite when provoked, and will use the rattle as a warning before a strike. Most bites occur when the animal is startled by a hiker, or the victim’s judgment is hampered by intoxication. The majority of species have hemotoxic venom, causing necrosis and preventing the formation of blood clots.