Snake Profile: Golden Lancehead Viper (with photos)

The golden lancehead viper (Bothrops insularis) is an astonishingly beautiful snake. It is also one of the most venomous pit vipers on the face of our planet.

The name of this viper comes from how it looks. The golden lancehead viper got it’s name from the light yellow/brown color combined with a lance-shaped head.

The viper is endemic only to the island of Ilha da Queinada Grande, which is bout 28 miles off the Brazilian coast.

This species of snake is incredibly dangerous. Their venom is extremely potent, and humans who are bit and not treated have an incredibly high mortality rate.

The deadly viper is so dangerous that locals prohibit anyone from entering the island. Scientists and herpetologists are only allowed to visit the island under special circumstances, and this still rarely occurs.

This is mostly due to the fact that the Bothrops insularis is possibly the most venomous snakes on the South American continent.

Much research has been conducted about the potency of the viper’s toxin. But, the actual fatality rates remain unknown because very few humans have been bitten by this viper.

This is mostly because the snake is endangered and local to a very small portion of our planet.

Isolated reports suggest that without treatment, death can occur quickly; even with treatment about 7-10% will die.

That’s just another reason as to why outsiders are typically not given permission to visit this species’ habitat.

Below, we will cover everything you need to know about the golden lancehead viper — from it’s habitat, diet, size and more.

Where Do Golden Lancehead Vipers Live?

The golden lancehead is endemic to only one island off the coast of Brazil, Queimada Grande island. This small island of 43 hectares has a varied terrain that ranges from a tropical rainforest to bare rock.

Further, The island has a temperate climate that ranges between 18-24 degrees C. It is the only home of the golden lancehead.

So, how did this mesmerizing viper end up on a tiny island just off the coast of Brazil?

Well, the common folklore is that the deadly snakes became trapped on the island thousands of years ago when the rising sea levels covered up the land connection with the mainland.

Over time, the forced selection pressure has permitted the snake to adapt to this new environment where they have done well until recently

In fact, the island is closed to the public for the following two reasons:

1. the snakes are so dangerous, and

2. these vipers are incredibly endangered.

To access the island one first needs permission from the Brazil Federal Conservation unit and the trip is accompanied by members of the Navy. Other than that, outsiders are not permitted on Ilha da Queinada Grande unless it’s for a really compelling reason.

Golden Lancehead Viper Facts


The closest living relative of Bothrops insularis is Bothrops jararaca. Both species have been very well studied. Overall, there are 3 dozen species of Bothrops, which are exclusively native to South America.

The Golden Lancehead Viper is One Dangerous Snake | r/imagesofthe1980s

The golden lancehead doesn’t make many headlines compared to other dangerous snakes. As mentioned before, this is mostly due to the fact that this species is endangered and located on a remote island with no human population.

Thus, there has never been a documented, fatal bite by this deadly viper.

Hence, why we don’t normally hear about how lethal the golden lanceheads’s venom actually is.

However, other accounts of vipers in this family biting a human do not fair well to the victims. In many cases, it results in a death — especially if not treated right away.

These vipers get a bad rap in South America. It appears that the Bothrops vipers kill more humans in South America than any other species.

Researchers believe that the venom of the lancehead is probably just as potent as other Bothrops species. Anecdotal data suggest that fatality rates are high, even with treatment.

Based on studies with other Bothrops, the venom usually first results in localized pain at the site of the bite along with some swelling.

Then, victims usually show signs like nausea, vomiting, and bloody blister formation. As the venom spreads into the body, the individual may develop kidney failure, internal bleeding, brain hemorrhage, and necrosis of muscle.

This all can happen within a few hours of being bitten. So, it’s very important that anti-venom is administered as soon as possible after a bite.

Golden Lancehead Viper Bite and Venom Potentency

This snake is so venomous, it’s said that the venom will melt a victims skin around the bite wound.

(CC BY-SA 4.0)

While no bites have been recorded, the venom has been extensively tested in laboratories. The results of these potency tests are alarming to say the least.

Laboratory studies reveal that the venom of the golden lancehead is at least 5 times more potent than that of Bothrops jararaca.

Also, the venom of the lancehead is also very fast-acting. Besides causing tissue destruction and softening the flesh, the venom also can cause bleeding.

The ability of the venom to rapidly destroy the tissues makes it easier for the viper to swallow the prey. Unfortunately, this ability would also be very painful and deadly for a human.

Finally, the venom of the lancehead also has neuro-toxic properties, which leaves the prey unable to escape because of paralysis. Essentially, the venom shuts down all motor skills, which makes for an easier to digest meal.

General Behavior

There isn’t a great idea of the true behaviors of this species. Reason being is because of how difficult it is to study them.

It is believed that golden lancehead vipers are partially arboreal. Basically, that means they tend to live and thrive in trees.

While the viper is perfectly able to climb trees, it also enjoys hiding away on the earth. The golden lance viper is known to hide in the dense forest and vegetation where it can hunt birds from the shelter of leaves or rock crevices. Also, it can climb and hunt birds in trees, too.

Do They Have Predators?

Based on the limited knowledge on this species, the golden lancehead viper has no predators on the island.

However, the island is also home to many other large birds, millipedes, various lizards, spiders, and other snakes. Any of these creatures could potentially prey on neonate vipers or viper eggs.

Unfortunately, because of lack of direct observation, not much is known of the golden lancehead and its ecological role on the island.

Illness Threats

Like other vipers, the golden lancehead can suffer from ticks, mites, and flukes. 

Size, Lifespan, and Reproduction

Golden Lancehead Size

When fully mature, the golden lancehead viper will grow to a length of 50-100 cm, or 20-40 inches. While they might not be large, these vipers are very deadly.

What do They Look Like?

The viper usually has a yellowish light brown color, with several triangular or rectangular white/grey blotches on the upper surface. | r/Strangepetsandanimal

These patches may vary in size from small to large and usually run opposite the dorsal median line. Their underbelly is usually pale yellow or cream-colored.

In captivity, the lancehead viper will develop a dark yellow color which most likely is due to ineffective thermoregulation that results in poor circulation of blood to the skin surface, 

The viper has a well-defined V-shaped head without any stripes around the eye. The name ‘lancehead’ has been derived to reflect the distinctive shape of the head of all vipers in the genus, Bothrops.

Lancehead refers to an elongated head with its sides meeting at the tip of the nose. Compared to other Bothrops species, Bothrops insularis has a much longer tail.

This is most likely is due to adaptation to a forest or tree life. Additionally, their unique tail permits the viper to maneuver with stealth and agility through the trees.

Golden Lancehead Viper Reproduction

Mating takes place once a year. It happens only in the months during the middle of the summer.

The mating function may take place either on the ground or on the trees. Like other viper species, the golden lancehead gives live birth.

The average litter size varies from 6-8 newborn vipers. Experts believe that they have a very similar size to other Bothrops species. This is only because no observational studies have been done on these specific vipers regarding size at birth.

Other species typically vary from 20-24 cm at birth with a weight of 9-10 grams. How fast these snakes grow and their lifespan remains a mystery.

The lack of population paired with a harsh environment for people make it difficult to study this species of viper.

Diet of the Golden Lancehead

Besides the golden lancehead, the Island is home to many other snakes.

By some estimates, there is one snake to every square meter of land.

Hence, there is stiff competition for food resources.

The island is also home to about 3 dozen established species of birds.

But the golden lancehead almost only consumes two species of bird: the southern house wren and a species of flycatcher.

Most of the birds are able to avoid the viper. However, birds mainly snack on bugs that are either on the ground or in trees.

Since the viper is known to be an adept climber, birds typically don’t stand a chance.

There are no known mammals on the island. So, the main diet of the golden lanchead likely consists of insects, lizards, spiders, smaller birds, amphibians, and other snakes.

Like other vipers, the golden head is believed to be an efficient killer. The humble viper is known to be a patient hunter.

It is likely to either hide in the trees, rock crevices, or under leaves waiting to ambush its prey. After biting and killing the prey, it usually remains on the ground during the process of ingestion. 

Because the island is small and has no known mammals, there is intense competition for food.

How does This Deadly Viper Hunt?

The golden lancehead kills the prey by first injecting the venom.

The prey usually stumbles and tries to flee. During this time, the venom will destroy the tissues making it easier for the snake to swallow. Once the prey is dead, the snake will track and swallow the animal.

Is The Golden Lancehead Viper Endangered?

Golden Lancehead Vipers are critically endangered, according to the IUCN red list.

Here are the top reasons as to why:

  1. Because of continued in-breeding due to lack of population.In the long run, inbreeding is harmful as most of the reptiles turn out to be sterile.
  2. In recent years, some locals from the coast have started fires to kill the snakes so that the land can be used for agriculture.
  3. Deforestation and the removal of vegetation has increased on the island
  4. Due to their rarity and unique beauty, golden lancehead vipers are subject to poaching and smuggling. Collectors will pay top dollar for these snakes. So, there is a pretty big smuggling issue of Golden Lanceheads.

The island of Queimada Grande is very small and with limited food resources, the golden lancehead faces a tough life.

The species is very sensitive to any change in the environment. The future of golden lancehead looks grim, and will only get better if more conservation efforts are put forth.

How Many Golden Lanceheads Exist?

Experts estimate that only 2,000-4,000 golden lancehead vipers reside on the island. That said, these numbers are gross under/overestimates because it is challenging to gauge how many actually exist on this treacherous island.

Most recently, a survey suggested that the population of these vipers is rapidly declining.

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