Friday, September 18, 2015

Russell's Viper

Russel's viper (Daboia russelli) is a large species of viper found throughout the Indian subcontinent and other parts of south-east Asia.  Most of the snakebites (about 50%) in the Indian subcontinent are caused by the Russell's viper.

Physical Features
The russell's viper is a large and bulky viper, normally growing about 1 to 1.2 meters long.  However, specimens over 1.5 m have been recorded.  The color of their dorsal side is generally brown of varying shades, tan or deep yellow.  Their are a series of dark ovals running along their back which are outlined successively by black and white.  Another series of similar ovals runs down each flank alternating with those on the back.  They have a triangular head with a blunt snout.  Their head is very distinct from the body and they have very short tails.  Their belly is white, yellowish or sometimes pinkish.  The coat of the russell's viper very closely resembles that of the rough scaled boa, a harmless snake.

Distribution and Habitat
The russell's viper is widespread in the Indian subcontinent and is also found in Thailand and the Indo-Australian archipelago.  It is most common in India, Sri Lanka, Pakistan and Myanmar.  It inhabits plains, grasslands and plantations.  However, it has been recorded at heights of 2,100 m in south India and 2,000 m in the Himalayas.  It is common along the west coast of India.  It is abundant in Punjab but quite rare in the Ganga Valley.

Their diet mainly consists of rodents like mice, rats, squirrels, etc.  However, they will eat anything like lizards, frogs and small birds.  Juveniles are known to be cannibalistic.

The russell's viper is largely nocturnal.  Adults are known to be sluggish while juveniles are more excited and alert.  When aggravated, they stand their ground and produce a loud hiss that is distinctly louder than other snakes.  They are slow movers.  However, when they strike, they hurtle themselves with such force that they may even leave the ground.  Adults normally just prefer to just hiss when disturbed while juveniles may be more aggressive and bite.

Reproduction Cycle
Russell's vipers are ovoviviparous.  This is a mode of reproduction where the embryo's develop inside eggs which remains in the mother's stomach till they are ready to hatch.  The embryo's are nourished by the egg yolk. After they hatch, the mother gives birth to them.  A russell's viper generally gives birth to litters of 20 to 40 young.  However they have been known to give birth to litters of 63 individual as well as to a single young.  The gestation period exceeds six months.  Gravid females have been recorded in all months of the year. Females give birth between the months of May and November.  They sexually mature at the age of 2-3 years. 

A dose of 50-70 mg is lethal to an adult human.  The bite results in immediate pain and swelling in that region.  Post 20 minutes, bleeding occurs in the gums, urine and sometimes sputum.  Necrosis (the premature death of cells due to injuries) is a common symptoms.  Heart rate falls and blood pressure drops.  The victim may die of kidney failure, septicemia or cardiac arrest.  Death from any of these may occur in a period of 1 to 10 days.  Russell's viper used to cause about 300,000 deaths per year in the Indian Subcontinent before the introduction of its antivenin.  This has reduced the deaths by russell's viper considerably. 

Saturday, January 24, 2015

Cotton-top Tamarin

The cotton-top tamarin (Saguinus oedipus) is a small species of primate found only in a small part of South America.  It is rated as "Critically Endangered" by the IUCN.  It is a popular exhibit in zoos all around the world.

Physical Features
The cotton-top tamarin is an unmistakable species.  It gets its name from the elegant, long, white flowing fur on its head.  They generally weigh only about 420-450 grams. Their body length can be about 20-25 cm long while their tail can be about 35-40 cm long. Their tail is not prehensile i.e. it has not adapted to hold or manipulate objects. Males and females are generally same in size.  Their face is generally black or gray in color with very fine white hair which is barely visible.  Their back (dorsal side) is covered with brown fur while their front (ventral side) is covered with white or yellowish white fur.  Their tail is also covered in brown fur.  Unlike other monkeys, the cotton-top tamarin's thumbs are not opposable.

Cotton top tamarin feeding on some dry fruits.
Cotton-top tamarins are omnivorous.  They equally depend on plant material and animal material.  They consume organisms that are smaller than them like small lizards, amphibians and insects. Insects are a main constituents of their diet.  Plant material consists of fruits, flowers, nectar, seeds and plant sap.  They require very nutritious and high energy foods due to their small size and high food intake.  

Distribution and Habitat
The range of cotton-top tamarins are limited to the north-western side of Colombia, between the rivers Atrato,  Cauca and Magdalena.  Even in this region, their habitat is fragmented. They live in both tropical humid forests as well as tropical deciduous forests, primary as well as secondary forests.  They prefer to live in the lower levels of forests but may descend to the ground in search of food or ascend tall trees for protection or food.  They sleep in foliage cover.

Cotton-top tamarins are diurnal.  They either live in pairs but more often live in groups. They spend the days foraging and grooming.  They are very social animals and each group may consist 5-15 members.  They follow a matriarchal system i.e. the leader of a group is the eldest female.  Cotton-top tamarins groups follow a "helper" system where males and older siblings take care of the young and newly born for sometime.

Life Cycle and Breeding
Infants along with parent.
In a group of 10-15 individuals normally only one male-female pairs breed.  It is very often for twins to be born.  The breeding season is between the months of April and July.  A female cotton-top tamarin gives birth to a single offspring or twins after a gestation period of 4-5 months.  Males take care and groom the infants more than the female.  Cotton-top tamarins are known to live in captivity for 20 years while in wild, they often live for about 13 to 14 years.

Conservation Status   
The cotton-top tamarin is rated as "Critically Endangered" by the IUCN.  There are approximately 6,000 individuals remaining.  Illegal pet trade and habitat fragmentation is the main cause of population decline.  It is said that between the 1960's and 1970's about 30,000 individuals were exported to the United Sates for bio-medical research.  The population is decreasing.  It was one of the most endangered species of primate in the world between 2008-2011.  It is protected by the law.  The Paramillo National Park is one of the most important stretch of forest for this species and comprises of 1800 square miles.  There are enough number of individuals in captivity for the sustenance of this species.  It is said that their are more captive individuals than wild ones.

Source of pic 2, pic 3 

Friday, January 23, 2015

Bengal Monitor

The Bengal monitor (Varanus bengalensis) is a common, medium sized monitor lizard found in the Indian Subcontinent.  It is rated as " Least Concern" by the IUCN but its population is decreasing due to habitat fragmentation and hunting.

Physical Features
Brightly colored juvenile
The length of a bengal monitor can range from 1 meter to 1.8 meters. Males are larger than females. These monitors can weigh up to 7 kilograms.  Its head is relatively small as compared to the body but its snout is more rounded than the water monitor, which is a main distinction other than the size.  It has a thick and stocky head and short limbs. Adults' dorsal side can be olive, gray, black or brownish in color with sparse black spots. The ventral side is generally yellowish. Juveniles are brightly colored with series of dark bars on the neck and back which are sometimes accompanied by spots.  Bengal monitors have external nostril openings known as nares which they can close on will to prevent the entering of water or any other particulate matter.

Distribution and Habitat
The bengal monitor is the most common monitor in the Indian Subcontinent.   They are also found in Iran, Malysia, Java and Sumatra.  They are absent in the Andaman Islands. They can be found in rainforests, swamps and arid regions.  They are often found in agricultural and cultivated land.  They can be found in burrows, tree hollows and termite mounds.

They eat insects, small mammals, amphibians and other lizards.  It basically eats anything it can overpower.  They may even scale trees to stalk bats.  Juveniles are almost completely insectivorous.  It is a common sight to see them stealing eggs from nests, be it a bird's or crocodile's.  It senses its prey by both smell and sight.

Habits and Behavior
Bengal monitors are diurnal creatures.  They often dwell in trees or burrows.  Just like snakes, they flick their tongues out to "taste the air".  They can run at high speeds and are very able climbers.  They are also good swimmers.  They are generally very docile creatures.  When alarmed or threatened, it tries lies still to remain unseen or escape notice. When cornered, it may even stand on forelegs and lash its tail repeatedly on the ground. Bites from these monitors are quite painful and once the jaw is embedded into the flesh, it is difficult to remove due to its curved teeth.  They lead a solitary life and have a keen eyesight.

Life Cycle and Breeding
Bengal monitor in Bannerghatta National Park, Karnataka, India.
Bengal monitors are known to survive for 20 years in captivity, though it is generally lesser in the wild.  Males become territorial during the mating season (which they are generally not). Males battles each other for mates by standing up on their hindlegs. Sounds made during the mating season are generally restricted to hissing though bellowing has been recorded.  About 1 to 3 clutches of eggs are laid by the females with each containing about 20-30 eggs.  The female digs a pit to place the eggs and covers it with soil.  She may build a few false pits around it to mislead predators.  The eggs hatch after and incubation period of 6-9 months.

Conservation Status
The bengal monitor is rated as "Least Concern" by the IUCN.  It is the most widespread monitor in the Indian subcontinent, which consists of most of its range.  Its population is decreasing in certain parts of its range due to hunting for skin.  Illegal pet trade is also a contributing factor.  It is now a protected species by many governments. 

Source of pic 2    

Saturday, September 6, 2014

Gaboon Viper

The gaboon viper (Bitis gabonica) is a species of viper found in Africa.  It is renowned for its long fangs.  It is quite common in its range.

Physical Features
The gaboon viper is the world's largest viperid, weighing about 8 kilograms.  It has the longest fangs of any snake, which can measure up to 5 cm.  It is the longest African viper, ranging from lengths of 1 to 2 meters(3 to 6.6 feet).  The gaboon viper has a flat, triangular head with two small, hornlike structures on its snout.  It has a stout body with distinguishing geometric shapes like triangles, diamonds and rectangles.  It has brownish skin with buffs of purple and pink.  Its head is thick due to the large venom glands present behind its eyes.  Its coloration allows it to blend with dried leaves which helps it ambush its prey.

The diet of a gaboon viper mainly consists of small mammals and birds.  It can even consume full grown rabbits, porcupines and monkeys.  There are even reports of it eating royal antelopes. 

Habitat and Distribution
The gaboon viper lives in tropical forests and open woodlands.  It lives on the forest floor where it camouflages among the leaf litters.  The gaboon viper is only present in Africa.  It is mainly in central, eastern and south eastern Africa with few isolated population in western Africa.  Some countries in its range are Kenya, Uganda, Nigeria, Sierra Leone, Togo, Guinea, Mozambique, Ghana and Zimbabwe.

Behavior and Venom
The fangs of a gaboon viper.
Gaboon vipers are considered to be very sluggish and slow moving but they strike with alarming speed.  It ambushes its prey by camouflaging with the surrounding.  It is a very tolerant snake and only bites when severely provoked.  When threatened, it gives a low, deep hiss.  Their venom is not very toxic but it is delivered in large amounts; the most by any snake.  It stores large amounts of venom in glands behind its eyes.  Gaboon vipers rarely display anger even when handled.  They are nocturnal and live on forest floors.

Life Cycle
Gaboon vipers are ovoviviparous (when the embryo develops in an egg and hatches inside the female itself) and give birth to litters of 60 young every 2 to 3 years.  They have gestation periods of 3 to 4 months.

Conservation Status
Gaboon vipers are very common in their range.   

Source of pic 1, pic 2       

Tuesday, April 29, 2014


The koala (Phascolarctos cinereus) is perhaps one of the most popular of the marsupials other than the kangaroo.  It is endemic to Australia.  It is rated as 'Near Threatened' by the IUCN and was previously hunted in large numbers for its fur.

Physical Features
The koala is a small marsupial that measures about 2 to 3 feet in length.  They have a very small tail that measures about 2 cm.  Males are larger than females.  Their weight ranges from 5 kg to 15 kg.  The koala is stockily built with teddy bear like features with woolly grayish brown fur and fluffy ears.  The fur on the ventral side is paler.  Koalas have one of the most insulating fur (dorsal side) of any marsupial while the ventral fur reflects solar radiation.  Males have more curved noses than females.  Koalas have short, powerful limbs with sharp claws that enable it to climb and cling on to eucalyptus trees on which it spends most of its life.  Koalas in the southern regions are found to be 50% larger than those in the north.  Koalas have the smallest brain in proportion to body weight of any animal.
A koala feeding.

Koalas are herbivorous.  The main constituent of their diet is eucalyptus leaves.  They may be found eating leaves from Acacia and Leptospermum.  They eat for about 4 hours in the night eating and may eat about 500 grams of leaves.  They eat leaves from about 30 species of eucalyptus trees out of the 600 species present.  They show more preference toward eucalyptus leaves with higher protein and lignin (polymer that is present in cell walls of plant cells).  They may descend to the ground for eating soil and gravel that helps in digestion.  The droppings of the mother is one of the first solid food eaten by young koalas as it carries disease fighting microbes.

Distribution and Habitat
Koalas are found in eastern Australia and inhabit eucalyptus forests.  They spend most of their time on eucalyptus trees.

A koala sleeping
After a gestation period of 25 to 35 days, a single young is born during summer.  Twins are occasionally born.  They are suckled for 6 months in the mother's pouch.  After that period, they cling onto the mother's back.  

Koalas are considered as one of the most laziest animals.  They are nocturnal and spend 4 hours in the night for feeding.  For the remaining 20 hours, they sleep.  They are arboreal and occasionally come to the ground either for eating soil or for crossing open spaces.  They normally lead a solitary life.

Conservation Status
The koalas are rated as 'Near Threatened' by the IUCN.  Koalas have few natural predators other than large birds of prey.  Sometimes, while crossing land, feral dogs attack and kill it.  A bacteria known as Chlamydia has caused a disease that affects koalas.  In the early 20th century, koalas were extensively killed for their fur.  Koalas are also affected by habitat destruction.  Now their numbers are slowly increasing due to the efforts of conservationists.  

Saturday, March 29, 2014

Transparent Animals

It is a little hard to believe that their are some animals in this world which are transparent. This transparency is caused either by the lack of pigmentation in a particular part of the body.  Here is a list of some of them:

Barreleye Fish

The barreleye fish (Macropinna microstoma) is a fish from the barreleye family.  Found at depths of about 700 meters, it is known for its transparent head.  It was first found in 1939 but the transparent head was not known as when it comes out of water, the head loses its transparency.  Its head is filled with a transparent liquid.  The two dots above the nose is often mistaken for eyes.  It is actually its nose.  The two spherical structures in the head is the eyes. The eyes are capable of rotating 360˚. It was first photographed with the transparent head in 2004.

Glass Frog

Glass frogs form the family Centrolenidae.  They are found in the Amazon rainforests.  Most of their body is green, except for the ventral part which is translucent, allowing you the see the heart, liver and the gastrointestinal tract.  They can reach lengths of 7 cm and are known to eat their own young.  Some species of frogs from this family have such a delicate skin that they can get killed even if a raindrop fall on their body from the sky.

Crocodile Icefish

Crocodile icefish (also known as white blooded fish) form the family of Channichthyidae, a family of perciform fish.  They are found in the Antarctic ocean.  They are transparent due to their blood which lacks the red pigment known as hemoglobin.  Hemoglobin is used to transport oxygen through the blood.  It is one of the only known vertebrates which lack hemoglobin.  It lives in waters which are about -1.9°C, which is the freezing point of seawater.  Due to the higher concentration of oxygen in such cold waters, it is able to survive.

Golden Tortoise Beetle

The golden tortoise beetle (Charidotella sexpunctata) is a species of beetle.  Its color ranges from gold to orange, earning it a name of 'goldbug'.  Its external margins are transparent due to the lack of pigmentation.  It changes color seasonally and also changes color when threatened.

Blue-bellied night wanderer

The blue bellied night wanderer (Cyanogaster noctivaga) is a species of fish found in the Amazon river.  It is known for its bright blue belly.  Most of its body is transparent, revealing its vertebral column.  It was discovered in 2011.  It immediately dies and loses its color after being removed from the water, making it difficult to examine.  It is mostly active in the night.

Glass Squid

The glass squids form the family Cranchiidae.  Their bodies are transparent.  Juveniles live in shallow waters as their transparency camouflages them when light passes through.  Adults descend to deeper waters and can be found at depths of 2 km below sea level.

Many jellyfish are also transparent like the moon jelly.

Source of pic 1, pic 2, pic 3, pic 5, pic 6.
Picture 4 was taken by Nita, a follower of this blog.

Wednesday, December 25, 2013

Common Hippopotamus

The common hippopotamus (Hippopotamus amphibus) is a species of even toed hoofed mammals endemic to Africa.  Though it is classified as a even toed hoofed mammal, it is thought to be more closely related to whales.  They are rated as 'Vulnerable' by the IUCN.

Physical Features
The hippopotamus is the third largest land animal by weight.  Males can weigh anywhere between 1.4 to 3 tonnes with females being smaller.  The largest hippopotamus was a male that weighed 4500 kilograms(4.5 tonnes).  Their bone density is slightly greater than that of water.  This allows it to gently sink in water.  However, if it inflates its lungs while on the surface of the water, it can remain afloat without much effort.  Hippopotamuses can grow about 9 to 15 feet long and have tails that can grow up to 1.5 feet.  Despite being so bulky, they can swim and walk underwater.  They can reach speeds of about 30 km/hr on land using their short, insubstantial looking legs.  Hippopotamuses feature very large jaws and can open their mouths at angle of 150 degrees.  Their body varies from a gray to blue-black upper body.  The lower part of their body has a slight pinkish tinge.  They have an expanded muzzle with the nose
The large canines and incisors of a hippopotamus
covered with sensitive bristles.  The hippopotamus has two layers of skin.  The first layer, known as the epidermis, is very sensitive and dries out fast.  The inner layer is extremely thick (about 3.5 cm thick).  Their eyes, ears and nostrils are all located on the top of the head as that is the part that mostly remains above water during their swim.  Other adaptations include webbed toes and nostrils with the ability to close.  Hippos can remain submerged underwater for over 5 minutes. Hippopotamuses are also known for their wide mouth.  They have incisors that can reach lengths of a foot and canines that can reach length of 1.5 feet.

The hippopotamus is mainly herbivorous, though some have been observed eating small animals.  The main constituent of its diet is savanna grass.  They generally graze at nights and are led to their food by a dung trail left by them.  They also eat commercial crops like rice present in agricultural regions.  A hippopotamus may eat about 40 kilograms of grass every day.  

Distribution and Habitat 
The hippopotamus is found in western, central, southern and eastern parts of Africa.  They generally inhabit short grasslands, muddy wallows, rivers and lakes.

The hippopotamus is mainly nocturnal.  It rests in water during day time and grazes during nights.  They make noises like squeals, bellows and rumbles.  They sometimes make noises characterized with a loud 'ho-ho-ho'.

Life Cycle
Females generally give birth to one calf in water after a gestation period of about 240 days. Females mature between the ages of seven and fifteen while males mature at the ages of six to 13.  Hippopotamuses can live for about 48 years in captivity.  In wild, they can live for about 45 years.  

Source of pic 1 and pic 2