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Reptiles of Dudhwa National Park
There are four classes of terrestrial or land dwelling animals with backbone, the reptiles form the middle element. They have evolved from the amphibians. The history of reptiles goes back many millions of years. On the basis of fosssil evidence they are believed to have originated during Pennsylvanian period 300 to 260 million years ago. They were the dominant form of vertebrate life on earth for the following 140 to 120 million years, the Mesozoic era of earth history. This was the age of reptiles, the period when the dinosaurs flourished.
Modern reptiles, which appeared during the Tertiary period of earth history sonic 70 million years ago. Presently, the number of species of living reptiles, which is about 6000 is almost double the number of species of present day mammals.
Reptiles are cold blooded animals, means that their body temperature varies with the outside temperature whereas birds and mammals which have a constant body temperature are known as warm blooded. Reptiles have poor body insulation and cooling mechanism as they lack sweat glands yet they have considerable capacity for regulating their body temperature. Thermo-regulation in reptiles is a behaviour function and is achieved by judicious use of available sunlight.
There are three types of body form in reptiles. The basic type is the lizard like shape. The crocodiles, monitor lizards and geckos are examples of this type of boxy shape. The legs are well developed. In the second type, the body is elongated and cylindrical as in many skinks and all the snakes; legs may be rudimentary or absent. In the third type, the turtles and tortoises, the trunk has become rigid and enclosed in a bony shell. Indian reptiles range in size from the massive crocodile with lengths up to seven metre and geckos less than 10 cm in total length.
Crocodiles belong to Crocodylidae family, an ancient group of reptiles in existence for millions of years. The survival of the crocodilians over a long period of earth history is perhaps due to their needs being easily met, living as they do on the edge of two life zones, water and land and being able to find their prey from both zones.
Dudhwa Tiger Reserve have two types of crocodiles - Marsh crocodile or Mugger and Ghanal. Both crocodilians show certain structural adaptations for a successful aquatic life. The nostril is placed at the tip of the snout enabling the animal to breathe when the rest of the body is submerged. The eye has a transparent third eyelid permitting limited underwater vision. Crocodilians are excellent swimmers, thetail being the main propellent.
MUGGER OR MARSH CROCODILE (CROCODYLUS PALISH-IS)
Mugger is found in Suheli, Mohana rivers of Dudhwa National Park and Girwa river of KATARNIAGHAT Wildlife Sanctuary. It attains a length up to 4 metre and weighs up to 200 kg. Mugger usually spend the day basking on the bank or islands in river. The open mouth of basking crocodiles is a method of heat control. Mugger is an excellent swimmer. On land, it rests on its belly, but walks and runs with the body well off the ground. The senses of sight, hearing and smell are well developed and the animal remains very alert while basking on land. It hunts more or less exclusivly in water; the food is largely fish but any animal that can be overcomed is preyed.
The scent glands are probably active during the breeding season and assist in the sexes locating each other. Mating takes place in the month of March. The female lays her eggs in pitcher shaped hole in sand up to 40 in a clutch. Incubation period slightly in excess of two months. The female protects the nest by lying either in the water close to the nest or nest itself It is a known fact that sex of a hatchling is determined by temprature of the nest.
Ghari al can attain a length of up to 7 metre. They can be easily distinguished from other crocodiles by the long and narrow snout which ends in a bulbous tip. The jaws have approximately 104 teeth. Adult male with a large pot like cartilaginous mass (ghara) on the tip of snout, hence the name Gharial. Presently it is found in Girwa river of KATARNIAGHAT Wildlife Sanctuary and this species is now endangered.
Gharial basks in midstream islands and sandbanks. A facile swimmer they are clumsy on land propelling themselves with their legs in a sliding movement when coming out to bask. They rarely move far from the riverbank. Gharial feeds on predominantly fish. occasionally takes turtles and other small animals.
Mating in Gharial takes place in the month of January-February and starts at the age of above 12 years. Gharial nests in the month of April and nesting season do not vary by more than 10 days every year. Nests normally are sited in sand on island which assures high incubation success. Incubation period ranges from 72 to 92 days. The young. as in other crocodilians grunt when ready to hatch. Gharials, like other crocodilians show parental care in the form of nest protection. release of young in water and guarding ofhatchling clusters.
TURTLES AND TORTOISES
Fresh water turtles and tortoises belongs to reptile Order Chelonia. Turtles and tortoises are easily recognised from all other animals by their characteristic bony shell. The shell has two parts, the carapace above and plastron below, joined alone the flanks between the fore and hind limbs. The shell has an outer layer of horny shields and an inner layer of bony plates. both regularly arranged. The body within the shell is rigid with the ribs fused to the bony plates, but the parts outside the shell, neck, limbs and tail are free moving. Land and freshwater forms have varying ability to retract these into the shell. Food habits vary. some species being carnivorous, some vegetarian and others omnivorous. The jaws lack teeth but in a few species the horny beak that serves in their place has tooth-like serrations. The sexes are not easily distinguished but the male generally has a longer tail and a concave plastron.
The majority of the species occur in the large river system of the Indo-Gangetic plain, many are semi-terrestrial. All turtles and tortoises bury their eggs in soil or sand for incubation. The eggs may be hard or soft-shelled depending on the species. Clutch size varies from ten to forty. The Chelonians are long lived.
The turtle fauna of India comprises 31 species. 15 speceis of them are found in Uttar Pradesh and all fifteen are found in Dudhwa Tiger Reserve. List includes :-
- Indian Roofed Turtle ( Pungshura tectum)
- Indian Tent Turtle (Pungshura tentoria circumdata)
- Indian Tent Turtle (Pungshura tentoriallaviventris)
- Brown Roofed Turtle (P ungshura smithii)
- Spotted Pond Turtle (Geocletnys hamiltonii)
- Crowned River Turtle (Hardella thud ii)
- Three-striped Roofed Turtle (Kachuga dhongoka)
- Painted Roofed Turtle(Kachuga Kachuga)
- Indian Eyed Turtle (Moreni a peters
- Indian Black Turtle (Melanochelys try uga)
- Tricarinate Hill Turtle (Melanochelys tricarinata)
- Indian Softshell Turtle (Aspideretes gangeticus)
- Indian Peacock Softshell Turtle (Aspideretes finnan)
- Indian Flapshell Turtle (Lissemys punctata)
- Smal I -h eaded Softshell Turtle (Chitra indica)
- Elongated Tortoise (hidotestudo elongata)
Snakes are misunderstood and feared. In India most snakes are absolutlely harmless to humans while only 4 species are responsible for many deaths every year. About 270 species of snakes are found in India. Snakes belong to Order Squamata of reptiles. The elongate body of the snake is remarkably supple and is able to make twisting and other movements impossible for other vertebrate animals. The scales on the body of the snake are imbricate, that is they overlap in the manner of tiles, and form patterns which are characteristic of the species.
The skin, and the scales on it. are so constructed that stretching is possible to an enormous degree enabling snakes to swallow large prey. The heat sensitive 'Pits' between the nostril and the eye in pit vipers can detect temperature change as slight as three thousandths of a degree Centigrade. Pits are very helpful in finding warm-blooded rodents or birds or even a slightly warm frog or toad on a cool dark night. Pythons have similar infrared receptors along their upper lips. The skin is shed periodically and the shed skin is often unbroken and maintains its form to a remarkable degree.
The mouth is armed with numerous teeth which are not embedded in sockets. The teeth are recurved and serve to hold the prey, and thus assist in swallowing which is virtually done by the two halves of the jaw alternately walking over the prey and thus pushing it down the throat.
Three types of fangs occur in harmful snakes. In the back fanged snakes, the last two or three teeth of the upper jaw are large and are grooved. The groove is connected by a duct to the poison glands. In the snakes with fangs in the front of the mouth such as the Cobras, Kraits and the Vipers the groove has become a closed canal for the conveyance of the poison.
The forked tongue in snakes is an organ of smell rather than of taste and serves to collect scent particles by its constant quiver and play. Snakes have no external ears and cannot hear noise carried through the air but they arc able to feel through their jaws, vibrations carried through the substratum. Snakes are sensitive to vibrations through the ground and in this way can feel you walking. The eye varies in size and effectiveness. In some snakes including the blind snake, the eye is hidden beneath a head shield. When visible the eye lack lids but have a transparent watch-glass like shield beneath which they move. The pupil may be circular, vertical or horizontal.
The majority of snakes lay eggs with a white or yellow parchment like shell. Parental care in the form of brooding is seen in many instances.
Some of snake species are found in Dudhwa Tiger Reserve.
- Indian Python (Python molurus)
- Indian Rat Snake (Ptyas mucosa)
- Cobra (Naja nab)
- Russel 's Viper (Daboia russelii)
- Himalayan Pit Viper (Gloydiushimalayanus)
- Common Krait (Bun gurus caeruleus)
- Banded Krait (Bungarus fasciatus)
- Fresh Water Snake (Enhydris enhydris)
- Checkered Keelback (Xenochroph is piscator)
- Blind Snake (Ramphotyphlops braminus)
- Red Sand Boa (Dyxjohnii)
- Common Vine Snake (Ahaetulla nasuta)
- Common Kukri Snake (Oligodon arnensis)
- Russell's Kukri Snake (01i,rdon taeniolcaus)
- Common Cat Snake (Boiga trigoncaa)
Two type of Monitor Lizards - Common Indian Monitor and Yellow Monitor along with few Gecko and Garden lizards are also found in the Reserve.