1. Russell’s viper (Daboia russelii)

Highly Venomous

Regional Names: Dighad

Family: Viperidae

Distribution: It is widely distributed in lowlands across the Indian subcontinent, including some parts of northeast India, and is also found in Bangladesh, Pakistan, Nepal, and Sri Lanka.

WLPA: Schedule II

IUCN: Not Evaluated (NE)

Venom: Hemotoxic Venom

            Morphology:

Its body is robust, thicker than most snakes, and covered with highly keeled, dry-looking scales. Its head is triangular, anteriorly pointed, clearly broader than the neck, and covered with small keeled scales. Its eyes are of medium size and bear vertical pupils. Its whole upper body is brown, reddish-brown, yellow, or grey, and except for the tail, it is distinctly marked with three series of hollow, rounded, or almond-shaped blotches, which is a very reliable character to quickly recognise it from a distance. Its underside is creamy-white with some ventral scales marked with semi-lunar black patches at random places.

2. Common Krait (Bungarus caeruleus)

Highly Venomous

Regional Names: Shankhuvarayan, Vellikettan, Kattuvirayan (Malayalam). Hindi: Karait, Kaili, Kaal Gandheraaj. Marathi: Manyar

Family: Elapidae

Distribution: It is widely distributed in most of the Indian Subcontinent, excluding the Northeast regions. It is also found in Bangladesh, Nepal, and Sri Lanka.

WLPA: Schedule IV

IUCN: Least Concern (LC)

Venom: Neurotoxic

Morphology:

A medium-sized snake that grows up to 150 cm but is usually found within a 100 cm range. Its body is glossy bluish-black with milky white bands in pairs on the underside, while it is plain white on the top. Its head is not much broader than the neck and bears entirely black eyes of medium size. 

Highly Venomous

Regional Names: Churuttamandali, Shofamandali (Malayalam)

Family: Viperidae

Distribution: It is widely distributed in low- to mid-elevations of most of the Indian mainland except the northeast states and Himalayan foothills. Also, it is reported from a few parts of Sri Lanka, Bangladesh, and Pakistan.

WLPA: Schedule IV

IUCN: Least Concern (LC)

Venom: Hemotoxic Venom

Morphology:

It is a small snake that can grow up to about 60 cm. But individuals above 50 cm are rare. Newly born individuals are around 8-9 cm. Its body is short, relatively thick, and dry in appearance due to highly keeled scales, and it ends with a short tail. Its upper body is reddish-brown or brown with a series of white-yellow blotches throughout the length. These blotches are guarded by white wavy lines throughout. Its underbody is creamy white or light yellow, usually with dark-colored dots. Its head is typically like other vipers—triangular and clearly broader than the neck. Its eyes are medium-sized and bear vertical pupils. A "plus" shaped mark on the top of the head is a useful feature to quickly recognize from a safe distance.

Highly Venomous

Regional Names: Hindi: Naag.

Family: Elapidae

Distribution: It is widely distributed across most of India, including some parts of the northeast states, and also found in Bangladesh, Nepal, and Pakistan.

WLPA: Schedule II

IUCN: Least Concern (LC)

Venom: Neurotoxic Venom

Morphology:

It is a large-sized snake that is usually found in the 120-150 cm range. Newborn individuals are about 25-30 cm. Its body is slender and uniformly thick from head to mid-body. Its colour is variable according to the region. In South India and coastal regions, it is found in a yellow-brown colour range and sometimes found with fine dark markings. In central and northern India, it is found in dark chocolate brown or black colour. It raises a hood when threatened, and then it can be easily identified. When not raising the hood, it can be identified by checking the head and neck of the same breadth, rounded snout, and patternless lips.

Introduction

The Russell’s Viper (Daboia russellii) is one of the most medically important venomous snakes of South Asia. It is a stout-bodied terrestrial viper recognised by its strongly keeled scales, distinct triangular head and characteristic series of large, dark-edged oval or rounded markings along the body.

Despite its reputation as a feared snake, the Russell’s Viper is also an important predator in terrestrial ecosystems, particularly because rodents form a major part of its diet. Its frequent occurrence in agricultural and human-dominated landscapes brings it into close proximity with people, making it important not only from an ecological perspective but also from a public-health perspective.

The species belongs to the family Viperidae and is one of the four snake species traditionally recognised as the medically important “Big Four” in India. The World Health Organization identifies Russell’s Viper among the major species responsible for serious snakebite envenoming in India.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Family: Viperidae
Subfamily: Viperinae
Genus: Daboia
Species: Daboia russelii

Authority: (Shaw & Nodder, 1797)

The currently accepted name is Daboia russellii. The species was originally described as Coluber russellii and later placed in Daboia. Daboia siamensis, formerly treated as a subspecies of Russell’s Viper, is now recognised as a separate species.

Identification & Scalation

Russell’s Viper has a combination of characters that can help distinguish it from other snakes occurring in its range.

Head

• The head is broad and distinctly separated from the neck.
• The head is covered with small, keeled, overlapping scales rather than large symmetrical shields typical of many other snakes.
• The eye has a vertically elliptical pupil.
• There is no loreal pit between the nostril and eye.
• The nostril is large and lies within a large nasal shield.
• There are generally 10–12 upper labial scales.
• The eye is surrounded by numerous small scales.

Body scales

The dorsal scales are strongly keeled and have approximately 27–33 longitudinal scale rows at midbody, except for the outermost row being less strongly keeled. Ventral scales number approximately 153–180, while the paired subcaudals number approximately 41–64.

Colour and pattern

The dorsal colour is generally light brown, greyish-brown or yellowish-brown, although considerable variation occurs.

The most characteristic pattern consists of three longitudinal series of large, dark-edged brown markings:

• one central or vertebral series, and
• two lateral series.

The central markings may become connected, producing a chain-like appearance along the back.

The ventral surface is generally yellowish to whitish and may show varying amounts of darker marking.

Morphology

Russell’s Viper is a heavy-bodied viper with a relatively short, tapering tail.

The head is broad and triangular when viewed from above and is clearly wider than the neck. The body is robust, giving the snake its characteristic stout appearance.

The strongly keeled body scales give the animal a rough-textured appearance. The combination of a stout body, strongly keeled scales, vertically elliptical pupils and the distinctive series of large dorsal markings makes the species particularly recognisable.

Individuals can become quite large; the recorded total lengths reach approximately 1.6 m, although individuals around 1–1.2 m are commonly discussed in biological and medical literature.

Distribution

Daboia russelii is distributed across South Asia, including:

• India
• Pakistan
• Nepal
• Bangladesh
• Sri Lanka
• Bhutan

Within India, records extend across a large part of the country, including Madhya Pradesh, Maharashtra, Gujarat, Rajasthan-region records, Punjab, Jammu and Kashmir, Himachal Pradesh, Uttar Pradesh, Bihar, Odisha, Telangana, Tamil Nadu, Kerala and parts of northeastern India. The exact distribution is not uniform across these regions.

It is important to distinguish Daboia russelii from Daboia siamensis, the Eastern Russell’s Viper, which is recognised as a separate species and occurs farther east in mainland Southeast Asia.

Habitat

Russell’s Viper is primarily associated with open and relatively dry habitats rather than dense forests.

It may occur in:

• grasslands,
• scrublands,
• open woodland,
• agricultural landscapes,
• plantations,
• pasture,
• rural gardens and
• other human-modified terrestrial habitats.

Its ability to occupy agricultural landscapes is particularly important because rodents are abundant in many such environments.

A field study in Karnataka demonstrated that Russell’s Vipers can spend substantial amounts of time in plantations and other human-dominated landscapes.

Behaviour

Russell’s Viper is primarily a terrestrial ambush predator.

Although traditionally described as mainly nocturnal, field research has shown that its activity is more flexible than the simple label “nocturnal” suggests. Individuals may bask during the day and can also adopt ambush-foraging postures during daylight, with activity influenced by temperature and season.

When disturbed, the snake may produce a characteristic loud hiss and adopt a defensive posture. It should never be approached, handled or deliberately provoked.

Juveniles can be particularly defensive and may bite readily when disturbed.

Diet

Russell’s Viper is primarily a rodent predator.

Its diet includes rodents such as mice and rats, which makes the species an important predator in agricultural ecosystems.

Other prey has also been recorded, including:

• shrews,
• squirrels,
• lizards,
• scorpions and
• other small animals.

Diet can change with age. Juveniles are known to consume smaller prey and may actively forage for lizards and other suitable animals.

This rodent-feeding behaviour is ecologically significant because it places Russell’s Viper within the natural predator network of agricultural landscapes.

Reproduction

Russell’s Viper is ovoviviparous, meaning that the developing young are retained within the female until birth rather than being laid as conventional external eggs.

The species can give birth to approximately 5–50 live offspring, while the IUCN account notes that litters of 20–40 young are common.

Mating generally occurs early in the year, and the gestation period extends for more than six months. Births have been recorded mainly between May and November, with many occurring during June and August.

Venom & Medical Importance

Russell’s Viper is a highly venomous snake and is one of the principal causes of serious snakebite envenoming in India.

Its venom can produce severe systemic and local effects. Clinically important manifestations include:

• disturbances of blood coagulation,
• abnormal bleeding,
• local pain and swelling,
• tissue damage,
• acute kidney injury, and
• in severe cases, life-threatening systemic complications.

The venom therefore has major effects on the haemostatic and renal systems.

The World Health Organization identifies Russell’s Viper as one of the major medically important snakes in India and notes that its bites contribute substantially to the burden of snakebite envenoming in South and Southeast Asia.

Importantly, snakebite is a medical emergency. A suspected venomous snakebite requires immediate medical attention and should not be treated with traditional or improvised methods. Appropriate antivenom and supportive medical care are the basis of treatment.

Conservation Status

IUCN Red List: Least Concern (LC)

The IUCN currently assesses Daboia russelii as Least Concern at the global level. This does not mean that individual populations are free from local threats. Habitat modification, persecution, road mortality and other human-related pressures can affect local populations.

Protection in India

Under India's current wildlife protection framework, Daboia russelii is listed in Schedule I of the Wildlife (Protection) Act, 1972, as amended in 2022, giving it a high level of legal protection. The Zoological Survey of India's Fauna of India reptile checklist also records the species as Schedule I and categorises it as IUCN Least Concern.

The PerSonaLife Perspective

The Russell’s Viper is often reduced to its reputation as a dangerous snake. That view tells only one part of its story.

It is a highly specialised predator that occupies an important ecological position, particularly in landscapes where rodents are abundant. At the same time, its venom makes encounters between humans and this species potentially dangerous.

The goal should therefore not be to portray the Russell’s Viper as either a “monster” or a harmless animal. It is a venomous wild animal that deserves respect, understanding and appropriate caution.

Learning to recognise the species, avoiding unnecessary interaction, protecting its habitat and ensuring rapid medical treatment after a suspected bite are far more effective approaches than fear, persecution or misinformation.

Understanding a snake is the first step toward coexistence.

Respect the species. Understand its ecology. Keep a safe distance.
#PerSonaLife

Literature Cited

Image Credits:-Animalia.Bio

The Greater Black Krait (Bungarus niger) is a highly venomous snake belonging to the family Elapidae. Unlike the strongly banded appearance associated with several other kraits, this species is remarkable for its uniform, glossy dark colouration. Its body may appear bluish-black, dark chocolate brown or dark grey, while the underside is contrastingly white or off-white.

The species occurs across parts of the Himalayan foothills and the northeastern Indian subcontinent, with records from India, Nepal, Bhutan and Bangladesh. In India, it has been recorded from Uttarakhand, West Bengal, Sikkim, Arunachal Pradesh, Assam, Nagaland, Manipur, Meghalaya, Mizoram and Tripura.

Greater Black Krait | Bungarus niger

The Greater Black Krait is a member of the genus Bungarus, commonly known as kraits. Kraits are elapid snakes and include some of the medically important venomous snakes of South and Southeast Asia. Bungarus niger is particularly distinctive because of its patternless dark body and enlarged vertebral scales.

Scientific Classification

Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Serpentes
Family: Elapidae
Genus: Bungarus
Species: niger

Binomial Name: Bungarus niger Wall, 1908

Identification and Scalation

The Greater Black Krait can be recognised by a combination of its dark colouration and distinctive scalation.

It has 7 supralabial scales, with the 3rd and 4th supralabials in contact with the eye. The loreal scale is absent.

The dorsal scales are smooth and arranged in 15 rows. One of its most useful identification features is the series of enlarged hexagonal vertebral scales, which are broader than long and distinctly larger than the scales adjacent to them.

The species has approximately 47–57 undivided subcaudal scales.

The enlarged vertebral scales are particularly useful in distinguishing the Greater Black Krait from the closely related Lesser Black Krait (Bungarus lividus).

Morphology

The Greater Black Krait is a medium-sized snake, reaching a maximum recorded length of around 130 cm in the information supplied here.

The entire dorsal surface is generally patternless and glossy, ranging from bluish-black to dark chocolate brown or dark grey. This uniform colouration gives the snake a rather understated appearance compared with the boldly banded kraits.

The underside is also patternless and is generally white or off-white, with the outer edges of the ventral scales showing grey shading.

The head is moderate in size and slightly broader than the neck. The snout is rounded. As in typical kraits, the eyes can appear entirely black, adding to the snake's distinctive appearance.

Its dark, glossy body and enlarged vertebral scales make it one of the more easily recognisable black kraits when seen clearly.

Distribution

The Greater Black Krait has a predominantly Himalayan and northeastern distribution.

In India, it is recorded from:

• Arunachal Pradesh
• Assam
• Manipur
• Meghalaya
• Mizoram
• Nagaland
• Sikkim
• Tripura
• Uttarakhand
• West Bengal

Beyond India, the species is known from Nepal, Bhutan and Bangladesh. The species was historically described from material associated with the eastern Himalayas, and subsequent records have considerably expanded our understanding of its distribution.

Habitat and Behaviour

The Greater Black Krait is a terrestrial snake and is principally active during the evening and night. Available records indicate that it can occur in forests and their surroundings, agricultural areas and human-modified landscapes, and may sometimes enter houses.

Like other kraits, it is an elusive snake and is not usually encountered openly during the daytime. Its dark colouration and nocturnal activity can make it particularly difficult to notice in its natural surroundings.

The species is oviparous, meaning that it reproduces by laying eggs.

Diet

Available information indicates that Bungarus niger is a predator capable of feeding on a variety of smaller animals. Recorded prey includes small snakes, rodents, frogs, lizards and fish.

As with other predatory snakes, its ecological role is important in regulating populations of its prey within the habitats where it occurs.

A Black Krait Without Bands

When people hear the word krait, they often imagine a snake covered with contrasting bands. The Greater Black Krait challenges that familiar image.

Its body is almost entirely dark and patternless, with the glossy surface sometimes showing bluish or chocolate tones depending on the light. Rather than relying on striking bands for recognition, this species has a different visual signature: a dark body, contrasting pale underside and enlarged vertebral scales.

This is one reason careful identification is important. A dark snake seen briefly at night should never be identified solely from colour.

Venom

The Greater Black Krait is highly venomous, and bites can cause serious envenoming. Krait venom is associated with neurotoxic effects, and documented cases involving Bungarus niger have included severe neuromuscular weakness and respiratory paralysis.

Therefore, this is a snake that should never be handled or approached for identification. If a bite is suspected, immediate medical attention is essential.

Conservation Status

According to the information supplied for this profile:

WLPA: Schedule IV
IUCN: Least Concern (LC)

The species is currently recognised as Bungarus niger by major reptile databases, with a distribution extending across India, Nepal, Bangladesh and Bhutan.

Its occurrence in human-modified habitats also highlights the importance of understanding snakes rather than killing them simply because they are venomous.

The PerSonaLife Perspective

The Greater Black Krait is a reminder that wildlife does not always need bright colours or dramatic patterns to be remarkable.

A glossy black body, completely black-looking eyes, and enlarged hexagonal vertebral scales are enough to make this krait unmistakable to an experienced observer. Yet for most people, it may simply appear to be another dark snake disappearing into the night.

Understanding species like Bungarus niger changes that perspective.

Fear may tell us to step away—but knowledge tells us what we are looking at.

And sometimes, one of nature's most fascinating animals is the one that chooses to remain almost completely hidden.

🐍 If this changed the way you see wildlife, pass it on. Stay with #Personalife as we continue exploring nature's hidden masterpieces. 🌿

Literature Cited

• Ahsan, M.F. & Rahman, M.M. 2017. Status, distribution and threats of kraits (Squamata: Elapidae: Bungarus) in Bangladesh. Journal of Threatened Taxa 9(3): 9903–9910.
• Captain, A., Tillack, F. & Kuch, U. Records on the distribution and identification of Bungarus niger in India.
• Indian Snakebite Initiative. Greater Black Krait (Bungarus niger) species profile.
• The Reptile Database. Bungarus niger Wall, 1908.
• Whitaker, R. & Captain, A. 2004. Snakes of India: The Field Guide.
• Malsawmda et al. 2021. First observation of male combat in the Greater Black Krait Bungarus niger. Herpetological Bulletin 155: 32–33.