Inland Taipan

The Inland Taipan is dark tan, ranging from a rich, dark hue to a brownish light-green, depending on season. Its back, sides and tail may be different shades of brown and grey, with many scales having a wide blackish edge. These dark-marked scales occur in diagonal rows so that the marks align to form broken chevrons of variable length that are inclined backward and downward. The lowermost lateral scales often have an anterior yellow edge. The dorsal scales are smooth and without keels. The round-snouted head and neck are usually noticeably darker than the body (glossy black in winter, dark brown in summer), the darker colour allowing the snake to heat itself while only exposing a smaller portion of the body at the burrow entrance. The eye is of average size with a blackish brown iris and without a noticeable coloured rim around the pupil. It has twenty-three rows of mid-body scales, between fifty-five and seventy divided subcaudal scales, and one anal scale. The Inland Taipan averages approximately 1.8 metres (5.9 ft) in length, although larger specimens can reach lengths of 2.5 metres (8.2 ft).

Inland taipans adapt to their environment by changing the color of the skin during seasonal changes. They tend to become lighter during summer and darker during the winter. This seasonal color change serves the purpose of thermoregulation, allowing the snake to absorb more light in the colder months.

The Inland Taipan consumes mostly rodents, small mammals and birds. Unlike other venomous snakes that strike with a single accurate bite then retreat while waiting for the prey to die, the Inland Taipan is known to deliver up to seven venomous bites in a single attack.

Inland Taipan produce clutches of between one and two dozen eggs. The eggs hatch two months later. The eggs are usually laid in abandoned animal burrows and deep crevices. Reproduction rate depends in part on their diet. If there is not enough food then the snake will reproduce less.

The inland taipan's venom consists of Taipoxin and protease enzymes. The average quantity of venom delivered by this species is 44 mg and the maximum dose recorded is 110 mg. The median lethal dose (LD50) for mice is 2 μg/kg (ppb) for pure Taipoxin and 30 μg/kg (ppb) for the natural venom mixture.Its venom consists mostly of neurotoxins. Almost all positively identified inland taipan bite victims have been herpetologists handling the snakes for study, and all were treated successfully with antivenom—no incidents have been fatal.

black mamba

The black mamba was first described in 1864 by Albert Günther, a German-born British zoologist, ichthyologist, and herpetologist. Soon after, a subspecies was identified, Dendroaspis polylepis antinorii (Peters, 1873), but this is no longer accepted as distinct. The genus and species name are derived from Ancient Greek words – Dendroaspis meaning "tree asp" (dendro is "tree", while aspis is "asp" which is understood to mean a "venomous snake") and polylepis, "many scaled", from poly "many" and lepis "scales". The name "black mamba" is given to the snake not because of its body colour but because of the ink-black colouration of the inside of its mouth, which it displays when threatened.In 1896, Boulenger combined the species (Dendroaspis polylepis) as a whole with the eastern green mamba, Dendroaspis angusticeps, and they were considered a single species from 1896 until 1946.

It is one of four species in the African snake genus Dendroaspis that are known as mambas.

The adult black mamba's back skin colour is olive, brownish, gray, or sometimes khaki. A young snake is lighter, but not light enough to be confused with the different species of green mamba. Its underbody is cream-coloured, sometimes blended with green or yellow. Dark spots or blotches may speckle the back half of the body, and some individuals have alternating dark and light scales near the posterior, giving the impression of lateral bars. The inside of the mouth is dark blue to inky black. The head is large but narrow and elongated, with the shape of a coffin. It is a proteroglyphous snake, meaning it has immovable, fixed fangs at the front of the maxilla. The eyes are dark brown to black, with a silvery-white to yellow edge on the pupils. These snakes are strong but slender in body: adult specimens are 2.5 to 3 m (8.2 to 9.8 ft) in length on average,but specimens measuring 3.1 to 3.75 m (10 to 12.3 ft) are relatively common, and some specimens have reached lengths of 4.3 to 4.5 m (14 to 15 ft). The longest scientifically measured, wild-caught black mamba recorded was 4.48 metres (14.7 ft) long, found in Zimbabwe. Adult black mambas' slender but powerful body can typically weigh from 1.6 to 3.1 kg (3.5 to 6.8 lb). There is no real sexual dimorphism, and both male and female snakes of this species have a similar appearance and tend to be similar in size.The species is the second-longest venomous snake in the world, exceeded in length only by the king cobra.Information regarding the lifespan of snakes in the wild is sparse; the longest recorded lifespan of a captive black mamba is 14 years, but actual maximum lifespans could be much greater.As they age, their colouration tends to get darker.

There are 23–25 rows of smooth dorsal scales at midbody (rarely 21 rows), 248–281 ventrals and 109–132 paired subcaudals. The anal shield is divided. There are 7–10 upper labials, with the fourth (or third and fourth) entering the eye, and 11–13 lower labials (sometimes 10 or 14). There are three (sometimes four) preoculars and three or four (sometimes two or five) postoculars. Temporals are variable, usually 2+3.

The black mamba has adapted to a variety of climates, ranging from savanna, woodlands, farmlands, rocky slopes, dense forests and humid swamps.The grassland and savanna woodland/shrubs that extend all the way from southern and eastern Africa to central and western Africa, eastern and southern Africa are the black mamba's typical habitat.The snake prefers more arid environments, such as semiarid, dry bush country, light woodland, and rocky outcrops. This species likes areas with numerous hills, as well as riverine forests. Black mambas often make use of abandoned termite mounds and hollow trees for shelter. The abandoned termite mounds are especially used when the snake is looking for somewhere to cool off, as the mounds are sort of a "natural air-conditioning" system. The structure of these mounds is very complex and elaborate. They have a network of holes, ducts, and chimneys that allow air to circulate freely, drawing heat away from the nest during the day – though without taking too much valuable moisture – while preventing the nest cooling too much at night.As a territorial species, though, the black mamba will always return to its territory or lair if left undisturbed.

copperhead

"copperhead." The behavior of Agkistrodon contortrix may lead to accidental encounters with humans. Five subspecies are currently recognized, including the nominate subspecies described here.
Adults usually grow to a total length of 50–95 cm (20–37 in), although some may exceed 1 m (3.3 ft). Males are usually larger than females. The maximum length reported for this species is 134.6 cm (53.0 in) for A. c. mokasen (Ditmars, 1931). Brimley (1944) mentions a specimen of A. c. mokasen from Chapel Hill, North Carolina, that was "four feet, six inches" (137.2 cm), but this may have been an approximation. The maximum length for A. c. contortrix is 132.1 cm (52.0 in) (Conant, 1958).

The body is relatively stout and the head is broad and distinct from the neck. Because the snout slopes down and back, it appears less blunt than that of the cottonmouth, A. piscivorus. Consequently, the top of the head extends further forward than the mouth.

The scalation includes 21–25 (usually 23) rows of dorsal scales at midbody, 138–157 ventral scales in both sexes and 38–62/37–57 subcaudal scales in males/females. The subcaudals are usually single, but the percentage thereof decreases clinally from the northeast, where about 80% are undivided, to the southwest of the geographic range where as little as 50% may be undivided. On the head there are usually 9 large symmetrical plates, 6–10 (usually 8) supralabial scales and 8–13 (usually 10) sublabial scales.

The color pattern consists of a pale tan to pinkish tan ground color that becomes darker towards the midline, overlaid with a series of 10–18 (13.4) crossbands. Characteristically, both the ground color and crossband pattern are pale in A. c. contortrix. These crossbands are light tan to pinkish tan to pale brown in the center, but darker towards the edges. They are about 2 scales wide or less at the midline of the back, but expand to a width of 6–10 scales on the sides of the body. They do not extend down to the ventral scales. Often, the crossbands are divided at the midline and alternate on either side of the body, with some individuals even having more half bands than complete ones. A series of dark brown spots is also present on the flanks, next to the belly, and are largest and darkest in the spaces between the crossbands. The belly is the same color as the ground color, but may be a little whitish in part. At the base of the tail there are 1–3 (usually 2) brown crossbands followed by a gray area. In juveniles, the pattern on the tail is more distinct: 7–9 crossbands are visible, while the tip is yellow. On the head, the crown is usually unmarked, except for a pair of small dark spots, one near the midline of each parietal scale. A faint postocular stripe is also present; diffuse above and bordered below by a narrow brown edge.

Several aberrant color patterns for A. c. contortrix, or populations that intergrade with it, have also been reported. In a specimen described by Livezey (1949) from Walker County, Texas, 11 of 17 crossbands were not joined middorsally, while on one side three of the crossbands were fused together longitudinally to form a continuous undulating band, surmounted above by a dark stripe that was 2–2.5 scales wide. In another specimen, from Lowndes County, Alabama, the first three crossbands were complete, followed by a dark stripe that ran down either side of the body, with points of pigment reaching up to the midline in six places but never getting there, after which the last four crossbands on the tail were also complete. A specimen found in Terrebonne Parish, Louisiana by Ernest A. Liner, had a similar striped pattern, with only the first and last two crossbands being normal.

Common names for copperhead (snake):A. contortrix, chunk head, death adder, highland moccasin, (dry-land) moccasin, narrow-banded copperhead, northern copperhead, pilot snake, poplar leaf, red oak, red snake, southeastern copperhead, white oak snake,American copperhead,southern copperhead,and cantil cobrizo (Spanish).

Like all pit vipers, A. contortrix is generally an ambush predator: it takes up a promising position and waits for suitable prey to arrive. One exception to ambush foraging occurs when copperheads feed on insects such as caterpillars and freshly molted cicadas. When hunting insects, copperheads actively pursue their prey.Juveniles use a brightly colored tail to attract frogs and perhaps lizards, a behavior termed caudal luring . In the southern United States, they are nocturnal during the hot summer months, but are commonly active during the day during the spring and fall.

Like most North American viperids, these snakes prefer to avoid humans and, given the opportunity, will leave the area without biting. However, unlike other viperids they will often "freeze" instead of slithering away, and as a result many bites occur from people unknowingly stepping on or near them.This tendency to freeze most likely evolved because of the extreme effectiveness of their camouflage. When lying on dead leaves or red clay, they can be almost impossible to notice. They will frequently stay still even when approached closely, and will generally strike only if physical contact is made.

Roughly 90% of its diet consists of small rodents, such as mice and voles. They have also shown fondness for large insects and frogs, and though highly terrestrial, have been known to climb trees to gorge on emerging cicadas.

A. contortrix breeds in late summer, but not every year: sometimes a female will produce young for several years running, then not breed at all for a time. They give birth to live young about 20 cm long: a typical litter is 4 to 7, but it can be as few as one or as many as 20. Their size apart, the young are similar to the adults, but lighter in color, and with a yellow-marked tip to the tail, which is used to lure lizards and frogs.

A study has shown that A. contortrix males have longer tongue tine lengths than females during the breeding season which may aid in chemoreception of males searching for females.

Although venomous, these snakes are generally not aggressive and bites are rarely fatal. Copperhead venom has an estimated lethal dose of around 100 mg, and tests on mice show its potency is among the lowest of all pit vipers, and slightly weaker than that of its close relative, the cottonmouth. Copperheads often employ a "warning bite" when stepped on or agitated and inject a relatively small amount of venom, if any at all. "Dry bites" involving no venom are particularly common with the copperhead, though all pit vipers are capable of a dry bite.

Bite symptoms include extreme pain, tingling, throbbing, swelling, and severe nausea. Damage can occur to muscle and bone tissue, especially when the bite occurs in the outer extremities such as the hands and feet, areas in which there is not a large muscle mass to absorb the venom. A bite from any venomous snake should be taken very seriously and immediate medical attention sought, as allergic reaction and secondary infection are always possible.

The venom of the southern copperhead has been found to hold a protein called "contortrostatin" that halts the growth of cancer cells in mice and also stops the migration of the tumors to other sites. Note, however, this is an animal model and as humans are not rodents, further testing would be required to verify safety and efficacy in humans.

Although technically the antivenin CroFab could be used to treat an envenomation, it is usually not administered for copperheads, as the risk of complications of an allergic reaction to the treatment are greater than the risk from the snakebite itself in most cases. Pain management, antibiotics, and medical supervision in the case of complications is usually the course of action.In 2002, the Illinois poison control center report on the availability of antivenin, the report stated it used 1 Acp to 5 Acp depending on the symptoms and circumstances. The symptoms of a mild envenomation include swelling of the hand, mild cellulitis, and respiratory distress. The symptoms of a moderate envenomation would include swelling of the hand, vomiting, mild bleeding, ecchymosis, diaphoresis, sinus tachycardia, and hypotensia.

Pythons

Pythons are found in sub-Saharan Africa, Nepal, India, Burma, southern China, Southeast Asia and from the Philippines southeast through Indonesia to New Guinea and Australia.

In the United States, an introduced population of Burmese pythons, Python molurus bivittatus, has existed as an invasive species in the Everglades National Park since the late 1990s.

Most members of this family are ambush predators, in that they typically remain motionless in a camouflaged position and then strike suddenly at passing prey. They will generally not attack humans unless startled or provoked, although females protecting their eggs can be aggressive. Reports of attacks on human beings were once more common in South and Southeast Asia, but are now quite rare.

Prey is killed by a process known as constriction; after an animal has been grasped to restrain it, a number of coils are hastily wrapped around it. Then, by applying and maintaining sufficient pressure to prevent it from inhaling, the prey eventually succumbs due to asphyxiation. The pressures produced during constriction have recently been suggested to cause cardiac arrest by interfering with blood flow, but this hypothesis has not yet been confirmed.

Larger specimens usually eat animals about the size of a house cat, but larger food items are known: some large Asian species have been known to take down adult deer, and the African rock python, Python sebae, has been known to eat antelope. Prey is swallowed whole, and may take anywhere from several days or even weeks to fully digest.

Contrary to popular belief, even the larger species, such as the reticulated python, P. reticulatus, do not crush their prey to death; in fact, prey is not even noticeably deformed before it is swallowed. The speed with which the coils are applied is impressive and the force they exert may be significant, but death is caused by suffocation, with the victim not being able to move its ribs to breathe while it is being constricted.

Females lay eggs .This sets them apart from the family Boidae (boas), most of which bear live young (ovoviviparous). After they lay their eggs, females will typically incubate them until they hatch. This is achieved by causing the muscles to "shiver", which raises the temperature of the body to a certain degree, and thus that of the eggs. Keeping the eggs at a constant temperature is essential for healthy embryo development. During the incubation period, females will not eat and only leave to bask to raise their body temperature.

GiantAnacondas

The first recorded sightings of giant anacondas were from the time of the discovery of South America, when early European explorers entered the dense jungles and claimed to have seen giant snakes measuring up to 18 metres (59 ft) long.Natives also reported seeing anacondas upwards of 10.5 metres (34 ft)to 18 metres (59 ft).Anacondas above 7 metres (23 ft) in length are rare. The Wildlife Conservation Society has since the early 20th century, offered a large cash reward (currently US$50,000) for live delivery of any snake of 9 metres (30 ft) or more in length, but the prize has never been claimed, despite the numerous sightings of giant anacondas. In a survey of 780 wild anacondas in Venezuela, the largest captured was 5 metres (16 ft) long.A specimen measured in 1944 exceeded this size when a petroleum expedition in Colombia claimed to have measured an anaconda which was 11.4 metres (37 ft) in length, but its claim has never been proven.

Scientist Vincent Roth claimed to have shot and killed a 10.3 metres (34 ft) specimen, but like most other claims, it lacks sound evidence. Another claim of a large anaconda was made by adventurer Percy Fawcett. Following his 1906 survey of the Bolivia/Brazil border, Fawcett wrote that he had shot an anaconda that measured some 19 metres (62 ft) from nose to tail. Once published, Fawcett’s account was ridiculed. Decades later, Belgian cryptozoologist Bernard Heuvelmans came to Fawcett's defence, arguing that Fawcett's writing was generally honest and reliable. In Fawcett's favour is the fact that he was conducting a field survey and would have had at his disposal suitable measuring instruments. In an earlier part of his diary,  he suspects a claim that an anaconda of 17.67 m. (58ft.) was discovered was "exaggerated" until his own discovery of the larger snake.

Historian Mike Dash writes of claims of even larger anacondas, alleged to be as long as 45 metres (148 ft), with some of the sightings supported with photos (although the photos lack scale). Dash noted if reports of a 18 metres (59 ft) anaconda strains credulity, then a 120 feet (37 m) long specimen would be an impossibility.