Showing posts with label indian snakes. Show all posts
Showing posts with label indian snakes. Show all posts

Saturday, 25 January 2014

Snake Myths And Facts

Snake Myths And Facts

 1) Snakes Go Blind During the Heat of Summer

It still surprises me how many people believe this myth. Snakes do not simply go blind based on temperature or time of year. However, snakes close to shedding their skins do experience a temporary loss or inhibition of vision as their old ocular scales, protective scales covering the eyes, begin to separate from new ones developing underneath.

During this time, the eyes appear a milky gray-blue, and the snake’s ability to see is minimal. In captivity, this period of temporary blindness may happen anytime before a shed, but snakes in the wild typically do not always eat as much as their captive counterparts, so they often shed old skins less frequently. In nature, especially in the southern United States, a great many snakes slip into a shed cycle in late summer, so perhaps the myth that all snakes “go blind” was born during this time of year.

2)Snakes chase people.

 Many people who have spent time outdoors have a story about being chased by snakes. But herpetologists, people who study reptiles and amphibians, never seem to have this experience. They find that snakes are always trying to escape. To understand this perceived behavior of a snake chasing someone, one must first realize that a snake has nothing to gain by chasing a person. A snake obviously could not eat a person and so is not looking for food. They are not vengeful and do not chase people out of sheer hate

3) Rattlesnakes always add one rattle a year.

 A rattlesnake adds one rattle every time it sheds its skin. Snakes may shed several times in the course of a year, each time adding a new rattle. Rattles also may break off. Determining a snake's age by counting rattles usually results in an inaccurate estimate of the snake's age.

4)snakes drink milk.

The real fact is that snakes hate milk and it is scientifically proved that when snakes are forced to drink milk they get sick.
3. It is falsely believed that snakes can listen to music. Snakes never dance to the tune of the snake charmers. In fact snakes cannot hear the music it is the movement of the snake charmer that forces the snakes to follow a particular movement.

5)It is a common myth that snakes dance to been played by charmers.

Snakes are normally unresponsive. They are unable to hear the sounds that are transmitted in the air. Their body helps to catch the vibrations from the surface. Snakes believe that the moving charmer & his instruments are going to attack them so they quickly change their position & constantly sway their heads in the direction of instruments. This is a safeguard posture.

6) Bite received from a snake in water is not poisonous.

 Another false belief is that a bite received from a snake in water is not poisonous but the fact is that venomous snakes either when bitten on land or on water is equally poisonous.

 7)Many people believe that there are ‘Two-headed’ snakes.

This myth about ‘Two-headed’ snakes generally gets popularized by the snake-charmers who always try to prolong this mythological state about snakes in India so that they can persist in their job of attracting huge crowds towards their snake shows. Actually ‘Two-headed’ snake does not exist.

Monday, 17 October 2011

Chrysopelea ornata:-flying snake or golden tree snake

Chrysopelea ornata is a colubrid snake found in South and Southeast Asia. It is, along with the other species in its genus Chrysopelea, very unusual in that it is capable of a type of gliding flight. It is also rear-fanged. Currently, three subspecies are recognized, including the typical form described here. The snake's striking looks and capability of gliding make it a popular choice for captivity.

Description

Chrysopelea ornata is usually green in color, with black cross-hatching and yellow or gold colored accents. The body, though slender, is far less so than in other tree snakes. It has a flattened head with constricted neck, a blunt nose and large eyes with round pupils.[1]

The lateral, sharp and pronounced keeled condition of the ventrals in association with the normal, not enlarged, vertebral row of scales distinguish this snake. The snakes rarely exceed 40 inches in length, the smallest being measured at 115mm[4] and the largest being 1,360 mm (4 ft 51/2 in) long. The tail is about one-fourth of the total length.[1]

Chrysopelea ornata has two major colour forms, which are largely determined by geographic locality, and their descriptions are given below:[1]

    In Sri Lanka and southern extent of its Indian range, the snake is primarily greenish yellow or pale green. Each scale has a black mesial streak or spot, and is more or less edged with black. The snake also has dark crossbars at intervals. A series of large, flower-shaped, reddish or orange vertebral spots may be present or absent. Ventrals greenish, outside the keel edged with black or spotted. Head black with vellow crossbars and spots. The flower-shaped spots are commoner in Sri Lanka than in south India.

    The second colour variety occurs Southeast Asia lacks the reddish vertebral spots, and has less prominent black crossbars.


Venom
This species is considered mildly venomous, with no confirmed cases of medically significant envenomation.

Red-spotted form of Chrysopelea ornata from North Bengal, India

Geographic range

India, Sri Lanka, Myanmar, Thailand, western Malaysia, Laos, Cambodia, Vietnam, China (Hong Kong, Hainan, Yunnan), Indonesia (Sumatra, Java, Borneo, Sulawesi), and the Philippines.

In India Chrysopelea ornata ranges from the Western Ghats, up to the Dangs, Katernia Ghat in Uttar Pradesh, North Bihar, northern West Bengal[1] eastwards to Arunachal Pradesh.[6] It is also found in the forests of the Andaman islands.[1]


Chrysopelea ornata climbing up prior to launching itself into the air
Behaviour

Chrysopelea ornata is diurnal and arboreal. The snake's gliding ability, while not as impressive as that of the paradise flying snake (C. paradisi), still makes it capable of moving from tree to tree with relative ease. These snakes are excellent climbers, being able move across even the smallest of branches and even straight up trees with few branches by using the edges of rough bark. They are frequently seen moving up a coconut palm, or up vertical rock faces in graceful curves, gripping the somewhat uneven surfaces with their scales. They tend to be nervous, fast-moving snakes, and will attempt to flee if disturbed, but will not generally hesitate to bite if handled. They are mildly venomous, but the venom is not considered to be dangerous to humans.[4] It is intended to assist in subduing fast moving, arboreal prey. C. ornata takes small arboreal prey, such as lizards, bats and small rodents.[7] It might also feed on bird eggs and insects. Also it is reported to take snakes occasionally, and to avoid frogs, though frogs are also reported being eaten. The snake stalks or pursues the prey and seizes it by the neck, which is duly crushed in its strong jaws.[4]


Flight
Chrysopelea ornata, like others of its genus, glides or parachutes. This is presumably done to cover distances faster, to escape predators, to catch prey, or to move around in forests. Flying snakes usually parachute from tree to tree, but sometimes launch themselves from trees onto the ground. They have been known to cross as much as 100m.[5]

It does this by climbing up to a height, which it does easily by virtue of its keeled belly scales, and then launching itself into mid-air. The snake contracts its ventral surface inwards to form a U-shaped concave depression along the entire length of their bodies, holding the outer edges of the ventral scales rigid. This concave surface acts like a parachute, and increases air resistance, allowing the snake to glide forward with the thrust of its launch. The snake undulates through the air, in a swimming-like motion. It holds the tail rigidly upwards, and by twisting the tail from side to side, it attains balance. This motion allows it to propel forward, landing clumsily at the end of its flight.[5]


Head of C. ornata with brilliantly coloured tongue exposed
Reproduction
Breeding habits are little known. The snake is oviparous[6] and six to twelve elongated eggs[1] are laid. Gravid females have been obtained in May and June and hatchlings in June. In Bangkok, according to Smith, mating takes place in June. Hatchlings measure 114–152 mm (4 1/2 to 6 in) in length, while the smallest gravid female recorded was 1,093 mm (3 ft 7 in) in length.[1]


Thursday, 6 October 2011

RING-NAKED SNAKE (Diadophis punctatus)

The ringneck snake or ring-necked snake (Diadophis punctatus) is a colubrid snake species. It is found throughout much of the United States, central Mexico, and south eastern Canada[2]. Ring-necked snakes are secretive, nocturnal snakes that are rarely seen during the day time. They are slightly venomous but their non-aggressive nature and small rear-facing fangs pose little threat to humans who wish to handle them. They are best known for their unique defense posture of curling up their tails exposing their bright red-orange posterior, ventral surface when threatened. Ring-necked snakes are believed to be fairly abundant throughout most of their range though no scientific evaluation supports this theory. Scientific research is lacking for the ring-necked snake and more in-depth investigations are greatly needed[3]. It is the only species within the genus Diadophis, and currently fourteen subspecies are identified, but many herpetologists question the morphologically-based classifications[4].
The Northern Ringneck Snake is a smallish snake, only growing up to two feet long. It is bluish-black in color, with a yellow or red ring around its neck, and a matching belly. This snake has a large, flat head.Northern Ringneck Snakes live just about anywhere, including forests, grassy places, and streamsides.They usually hide under logs, rocks, leaf litter, or matted plants.They are nocturnal, so they are mostly seen at night.

                                                                                  

  Physical description

Ring-necked snakes are fairly similar in morphology throughout much of their distribution.


Dorsal coloration is solid olive, brown, bluish gray to black, broken only by a distinct yellow, red, or yellow-orange neck band[2][5]. There are a few populations in New Mexico, Utah, and other distinct locations that do not have the distinctive neck band[2]. Additionally individuals may have a reduced or partially colored neck band that is hard to distinguish; coloration may also be more of a cream color rather than bright orange or red[5]. Head coloration tends to be slightly darker than the rest of the body with tendencies to be blacker than grey or olive[5]. Ventrally the snakes exhibit a yellow-orange to red coloration broken by crescent shaped black spots along the margins[2]. Sometimes individuals lack the distinct ventral coloration but typically retain the black spotting[5]. Rarely do individuals lack both the ventral or neck band coloration so use of those two characteristics are the most simple way to distinguish the species[2].


Size also varies across the species distribution. Typically adults measure 25-38 cm (10-15 inches)[2], except for D. punctatus regalis which measures 38-46 cm (15-18 inches)[5]. First year juvenile snakes are typically about 20 cm (4 inches) and grow about 2-5 cm (¾-2 inches) a year depending on the developmental stage or resource availability[5].


Ring-necked snakes have smooth scales with 15-17 scale rows at mid body[2]. Males typically have small tubercles on their scales just anterior to the vent which are usually absent in females[2].


Habitat

Ring-necked snakes occur in a wide variety of habitats. Preference seems to be determined by areas with abundant cover and denning locations spaces[5]. Northern and western species are found within open woodlands near rocky hillsides, or in wetter environments with abundant cover or woody debris[2]. Southern species exist primarily within riparian and wet environments, especially in more arid habitats[5]. Stebbins (2003) identified the species as a snake of moist habitats, identifying that moist soil conditions were the preferred substrate[2]. Ring-necked snakes are also not found above an elevation of 2200 meters[2]. In northern regions, dens are also important in identifying suitable ring-necked snake habitat. Dens are usually shared communally[5], and are identifiable by an existent subsurface crevasse or hole that is deep enough to prevent freezing temperatures. Since it is a woodland reptile, it can commonly also be found under wood or scraps. Because of the hot weather, they tend to make holes and burrow or they decide to hide under rocks or any suitable material. They are normally found in flatland forests.



Behavior
The diet of the ring-necked snake consists primarily of smaller salamanders, lizards, frogs, earthworms, and some juvenile snakes of other species[5]. The frequency at which prey species are chosen is dependent on their availability within the habitat[5]. Ring-necked snakes use a combination of constriction and envenomation to secure their prey. The snakes do not have a true venom gland, but they do have an analogous structure called the Duvernoy’s gland derived from the same tissue[3]. Most subspecies are rear-fanged with the last maxillary teeth on both sides of the upper jaw being longer and channeled[3]; the notable exception is D. punctatus edwardsii which is fangless[5]. The venom is produced in the Duvernoy's gland located directly behind the eye[3]. It then drains out of an opening at the rear of the maxillary tooth[3]. Ring-necked snakes first strike and then secure the prey using constriction. Next they maneuver their mouths forward ensuring that the last maxillary tooth punctures the skin allowing the venom to enter the prey's tissue[3]. Ring-necked snakes are rarely aggressive to larger predators suggesting that their venom evolved as a feeding strategy rather than a defense strategy. Rather than trying to bite a predator, the snake winds up its tail into a corkscrew, exposing the brightly colored belly[5].

Ring-necked snakes are primarily nocturnal or highly crepuscular, though some diurnal activity has been observed[5]. Individuals are sometimes found during the day, especially on cloudy days, sunning themselves to gain heat[5]. Yet, most individuals lie directly under surface objects that are warmed in the sun and use conduction with that object to gain heat[5]. Even though ring-necked snakes are highly secretive, they do display some social structure; but the exact social hierarchies have never been evaluated[5]. Many populations have been identified to have large colonies of more than 100 individuals, and some reports identify that some smaller colonies occupy the same microhabitats[5].


Reproduction
Ring-necked snakes usually mate in the spring. However, in some subspecies mating occurs in the fall, and delayed implantation occurs.[5]. Females attract males by secreting pheromones from their skin[5]. Once the male finds a female he starts by rubbing his closed mouth along the female’s body[5]. Then the male bites the female around her neck ring maneuvering to align their bodies so sperm can be inserted into the female’s vent[5]. Females lay their eggs in loose aerated soils under a rock or in a rotted log[4]. Three to ten eggs are deposited in early summer and hatch in August or September[5]. The egg is elongate with a white color contrasted by yellow ends[5]. When hatched, juveniles are precocial and fend for themselves without parental care[5].


Distribution
Ring-necked snakes are fairly common throughout much of the United States extending into Southeastern Canada and central Mexico. Eastern populations cover the entire eastern seaboard from the Gulf of Saint Lawrence continuous through the gulf coast of north Texas[5]. Distribution moves inland into northern Minnesota continuing diagonally through the US to include all of Iowa, eastern Nebraska, and most of Kansas[5]. In the western US the distribution is significantly less continuous, with spotty distinct population segments through most of the Pacific Northwest[2]. Populations extend from south-central Washington continuing along the extreme west coast into Mexico[2]. Population segments extend inland into western Idaho, through southern Nevada, into central Utah, and continuing south through Arizona and central Mexico[2


Thursday, 15 September 2011

Big Four (Indian snakes)

The Big Four are the four venomous snake species responsible for causing the most snake bite cases in South Asia (mostly in India).

Indian cobra, Naja naja, probably the most famous of all Indian snakes :-


Common krait, Bungarus caeruleus:-

Russell's viper, Daboia russelii:-

Saw-scaled viper, Echis carinatus:-