G
Species Profile

Golden Lancehead

Bothrops insularis

Snake Island's golden ambush viper
Nayeryouakim / Creative Commons

Golden Lancehead Distribution

Click a location to explore more animals from that region

Endemic Species
Loading map...

Found in 1 country

golden lancehead vs fer-de-lance

At a Glance

Wild Species
Also Known As Island lancehead, Queimada Grande pit viper, Ilha da Queimada Grande viper, jararaca-ilhoa, jararaca da Ilha da Queimada Grande
Diet Carnivore
Activity Cathemeral+
Lifespan 12 years
Weight 0.8 lbs
Did You Know?

Endemic range: only on Queimada Grande Island (Snake Island), about 0.43 km2 (43 ha) in area, roughly 33-35 km off the coast of Sao Paulo state, Brazil.

Scientific Classification

A highly venomous New World pit viper (lancehead) restricted to Ilha da Queimada Grande (“Snake Island”) off the coast of São Paulo, Brazil, noted for its golden/yellowish coloration and insular adaptation.

Kingdom
Animalia
Phylum
Chordata
Class
Reptilia
Order
Squamata
Family
Viperidae
Genus
Bothrops
Species
Bothrops insularis

Distinguishing Features

  • Golden-yellow to tan coloration (often more uniform than many mainland Bothrops)
  • Heat-sensing loreal pits typical of pit vipers (Crotalinae)
  • Triangular viper head and stout body; keeled scales
  • Island-endemic distribution (Ilha da Queimada Grande, Brazil)

Physical Measurements

Males and females differ in size

Length
2 ft 4 in (1 ft 8 in – 2 ft 11 in)
3 ft 2 in (2 ft 7 in – 3 ft 10 in)
Weight
1 lbs (0 lbs – 1 lbs)
Tail Length
5 in (3 in – 6 in)
6 in (4 in – 7 in)
Top Speed
2 mph
No measured top speed
Venomous

Appearance

Primary Colors
Secondary Colors
Skin Type Dry, heavily keratinized reptilian integument with keeled dorsal scales (matte/rough texture typical of pit vipers), enlarged ventral scutes for locomotion; periodic ecdysis (shedding) changes brightness/contrast.
Distinctive Features
  • The Golden Lancehead (Bothrops insularis) lives only on Queimada Grande (Snake Island) off São Paulo, Brazil; long island isolation gave it a golden to yellowish color and island adaptations.
  • Body size (reported): adults commonly around ~70-100 cm total length; maximum reported total length approximately ~118 cm (compiled species accounts in Campbell & Lamar, 2004; additional field summaries in Martins et al., 2002).
  • Classic pit-viper head morphology: broad, triangular 'lancehead' profile with a distinctly set-off neck; vertical pupils; strongly developed jaw musculature.
  • Thermosensory loreal pits: one heat-sensing pit between the eye and nostril on each side of the head (a defining pit viper trait).
  • Solenoglyphous venom system: long, hinged, front fangs that fold against the roof of the mouth when not in use; large venom glands create a pronounced posterior head bulge.
  • Semi-arboreal tendency reflected in form/behavior: often uses shrubs/low trees and perches to ambush prey (notably birds), which influences the typical posture and where the patterned dorsum is seen in the field (Martins et al., 2002).

Sexual Dimorphism

Sexual size dimorphism is reported: females are typically larger-bodied/longer in snout-vent length, while males tend to have proportionally longer tails (a common snake pattern tied to hemipenes). Marked color-based dimorphism is not generally emphasized for this species in standard accounts (e.g., Campbell & Lamar, 2004; Martins et al., 2002).

  • Proportionally longer tail (relative to total length), with a more noticeable post-cloacal taper.
  • On average smaller-bodied than females at maturity (field accounts note female-biased size).
  • Typically larger/heavier-bodied than males (female-biased size dimorphism reported in field literature).
  • May present a comparatively more robust trunk when gravid (viviparous species).

Did You Know?

Endemic range: only on Queimada Grande Island (Snake Island), about 0.43 km2 (43 ha) in area, roughly 33-35 km off the coast of Sao Paulo state, Brazil.

Adult size is typically ~70-100 cm total length; the largest recorded individuals are ~118 cm (reported in field/museum datasets for the species).

Diet shifts with age: juveniles take ectotherms (e.g., lizards), while adults feed heavily on birds-unusual among lanceheads (Bothrops).

It is a true pit viper: it has heat-sensing loreal pits and long, rotating (solenoglyphous) front fangs typical of Viperidae:Crotalinae.

Conservation status is Critically Endangered (IUCN Red List: Bothrops insularis), largely because its entire natural range is a single tiny island plus pressures like illegal collection and habitat disturbance.

Its yellow-to-golden coloration is a hallmark trait and helps it blend with island vegetation and leaf litter in sunlight-dappled habitats.

Venom research on B. insularis has been important for understanding how insular predators adapt toxins to local prey-especially bird-focused predation (documented in comparative venom studies of Bothrops).

Unique Adaptations

  • Extreme island endemism: the entire species is naturally confined to one small island, making it highly vulnerable but also a clear example of rapid insular differentiation from mainland lanceheads.
  • Bird-oriented predation toolkit: compared with many mainland Bothrops that focus heavily on mammals, B. insularis shows ecological and venom differences consistent with a bird-rich diet (supported by comparative toxin/enzymatic studies).
  • Golden/yellowish ground color: unusually bright for a Bothrops, improving camouflage in the island's sunlit, yellow-green vegetation mosaic.
  • Semi-arboreal posture and site use: frequent use of elevated ambush sites aligns with avian prey capture and reduces reliance on ground-based encounters.
  • Crotaline sensory specialization: infrared-sensitive loreal pits (a pit-viper hallmark) aid detection and targeting of warm prey even under low light and cluttered vegetation.

Interesting Behaviors

  • Semi-arboreal ambush hunting: often waits coiled on shrubs or low branches where birds perch, striking from concealment rather than actively chasing prey.
  • Ontogenetic diet shift: juveniles target small ectotherms; adults increasingly specialize on birds, matching changes in body size and hunting sites.
  • Caudal luring (juveniles): tail-tip twitching to draw curious lizards within strike range-behavior reported in Bothrops species and documented for island lanceheads in natural-history observations.
  • Sit-and-wait strategy with long stillness: like many vipers, it relies on crypsis and patience, punctuated by extremely rapid strikes.
  • Seasonal/episodic feeding: bird availability (including seasonal movements/stopovers) can produce feast-or-famine feeding patterns compared with mainland congeners.

Cultural Significance

The Golden Lancehead (Bothrops insularis) is tied to Queimada Grande Island (Snake Island), an off-limits island. It is a symbol of how tiny ranges raise extinction risk, appears in media, and helps lead venom research and debates on wildlife trafficking and ethics of collecting.

Myths & Legends

The Snake Island taboo warns people not to land on Brazil's island home to the Golden Lancehead (Bothrops insularis). Stories say it is full of venomous snakes and so dangerous it is forbidden.

A common island legend says a lighthouse keeper (sometimes with family) was killed when Golden Lancehead (Bothrops insularis) snakes entered the house. It says the lighthouse was made automatic and the island left to snakes.

Fishermen's cautionary yarns: regional anecdotes describe boats drifting too close and crews seeing snakes in the brush "like moving vines," using the image to warn younger fishers away from the island's shores.

Local tales say the island got its name from long ago fires set to clear land or drive animals away, after which golden lancehead snakes (Bothrops insularis) took back the island.

Treasure-and-curse narratives: occasional popular tales link the island's danger to buried pirate treasure or a 'curse' guarding the shore-modern storytelling that rides on the snake's real reputation.

Conservation Status

CR Critically Endangered

Facing an extremely high risk of extinction in the wild.

Population Decreasing

Protected Under

  • Ilha da Queimada Grande has restricted access under Brazilian federal control/management (landings are generally prohibited without authorization), which functions as the principal in-situ protection measure for Bothrops insularis.
  • Collection, transport, and commercialization of native Brazilian wildlife are prohibited/regulated under Brazil's wildlife and environmental crime frameworks (e.g., Lei de Proteção à Fauna-Law 5.197/1967; Lei de Crimes Ambientais-Law 9.605/1998), supporting enforcement actions against poaching/trafficking.
  • Species profile notes (to anchor conservation context with published natural history): Bothrops insularis is a highly venomous, semi-arboreal/arboreal ambush predator with strong reliance on migratory birds in adult diet; published accounts commonly report adult total length roughly ~70-100 cm with occasional records approaching ~118 cm, females averaging larger than males; the species is viviparous with small litters (often single-digit neonates) and a life history typical of Bothrops, making populations sensitive to adult removal. (Key sources commonly cited in the literature include ecological work by Marques and colleagues and other Brazilian herpetological field studies.)

Life Cycle

Birth 5 neonates
Lifespan 12 years

Lifespan

In the Wild
8–18 years
In Captivity
12–25 years

Reproduction

Mating System Promiscuity
Social Structure Solitary
Breeding Pattern Seasonal
Fertilization Internal Fertilization
Birth Type Internal_fertilization

Bothrops insularis is a solitary pit viper with brief, seasonal mating and internal fertilization. It is viviparous (live-bearing). The mating system is promiscuous; multiple mating and sperm storage are likely. No parental care; young are independent at birth.

Behavior & Ecology

Social None (solitary) Group: 1
Activity Cathemeral, Nocturnal, Crepuscular, Diurnal
Diet Carnivore Migratory passerine birds

Temperament

Sit-and-wait (ambush) predator; typically remains motionless for long periods on ground or in vegetation, striking when prey comes within range (documented for B. insularis in island field observations).
Generally cryptic and avoidance-oriented when undisturbed; becomes defensive when approached closely, cornered, or handled.
High-risk, highly venomous species; defensive bites can occur if threatened-handling/close approach is a major trigger rather than active pursuit of humans.
Golden Lancehead (Bothrops insularis) are more active in warm, wet times and less active in cool, dry times; they move between ground and tree perches as prey becomes available.

Communication

Hissing (defensive exhalation) when threatened; snakes lack true vocal calls but can produce audible hisses as a deterrent.
Chemical communication via tongue-flicking/vomeronasal sensing of pheromones and scent trails (mate-finding and assessment), consistent with viperid reproductive ecology and reported for Bothrops spp.; applicable to B. insularis.
Tactile communication during courtship and mating Body alignment, contact, cloacal apposition
Vibration/substrate-borne signaling through body movement (e.g., rapid tail movement against leaf litter/vegetation) used defensively in some viperids; reported anecdotally for lanceheads in the field.
Visual signaling via posture (S-coil, head elevation, strike-ready orientation) and slow withdrawal/immobility as primary threat management rather than overt displays.

Habitat

Biomes:
Tropical Rainforest Marine
Terrain:
Island Coastal Rocky
Elevation: Up to 675 ft 10 in

Ecological Role

Insular top predator (apex/mesopredator) shaping the island's terrestrial food web, strongly linked to seasonal pulses of migratory birds.

Regulates prey populations (especially migratory/resident small birds and juvenile-stage lizard prey) Stabilizes insular trophic dynamics by concentrating predation pressure on transient bird influxes Contributes to nutrient redistribution on the island via ingestion and deposition (feces/carcass remains), indirectly supporting decomposers/scavengers

Diet Details

Main Prey:
Migratory passerine birds Small birds Small lizards

Human Interaction

Domestication Status

Wild

Golden lancehead (Bothrops insularis) is a wild pit viper found only on Queimada Grande (Snake Island), Brazil. It has not been domesticated or bred for people. Human contact is rare and limited to controlled research and conservation because the island is closed and the species is Critically Endangered. Mainland relatives have more human contact.

Danger Level

Extreme
  • Medically significant envenomation risk typical of viperids: rapid local tissue injury plus systemic hemotoxic effects (e.g., coagulopathy/bleeding risk) requiring urgent hospital care and antivenom.
  • High consequence of bites compounded by handling risk: this is a highly venomous pit viper; safe interaction requires professional protocols (secure caging, bite-proof tools, antivenom access, emergency plans).
  • Bite incidence is low in the general public because the species is confined to a restricted island, but risk to authorized researchers/handlers is inherently high during capture or husbandry.

As a Pet

Not Suitable as Pet

Legality: Not recommended and usually illegal to keep Bothrops insularis as a pet. In Brazil you need federal permits (IBAMA/ICMBio); island access is limited and trade or export is mostly banned. Check laws.

Care Level: Expert Only

Purchase Cost:
Lifetime Cost:

Economic Value

Uses:
Biomedical/venom research (public health, toxinology) Antivenom and hemostasis research (indirect value; research material) Conservation science and protected-area management Education/outreach value (primarily via accredited institutions, not tourism due to access restriction)
Products:
  • peer-reviewed scientific data on venom composition and evolution in insular vipers
  • reference venom/toxin isolates for laboratory research (handled under strict permits)
  • conservation status assessments and management plans

Relationships

Predators 3

Roadside hawk Rupornis magnirostris
Southern caracara Caracara plancus
Great kiskadee
Great kiskadee Pitangus sulphuratus

Related Species 6

Ecological Equivalents 4

Animals that fill a similar ecological role in their ecosystem

Shedao pit viper Gloydius shedaoensis Strong niche analogue: an island pit viper that ambushes and feeds on migratory birds from vegetation, as seen in the Golden Lancehead (Bothrops insularis) and in Gloydius shedaoensis on Shedao Island.
Alcatrazes lancehead Bothrops alcatraz Closest ecological analogue within Bothrops. Brazilian offshore-island endemic with reduced dispersal, small-range population structure, and insular shifts in diet and behavior relative to mainland Bothrops. Both species exhibit island-driven ecological divergence compared with B. jararaca-like ancestors.
Jararaca
Jararaca Bothrops jararaca Mainland sister species Bothrops jararaca is used as the baseline for comparing island shifts in habitat, prey, and venom. Bothrops insularis is more arboreal and consumes more birds than mainland Bothrops jararaca.
Green tree pit viper Trimeresurus albolabris Functional niche similarity: a semi-arboreal, vegetation-ambushing pit viper that frequently preys on birds, especially where they are available. Included as a convergent ecological counterpart despite distant relatedness (Old World vs New World pit vipers).
Click to play on YouTube

The island-dwelling golden lancehead snake is one of the most venomous snakes in the world.

It only lives on one island 30 miles off the coast of Brazil and eats birds primarily. This is a slender pit viper with a golden color and a spearhead-shaped head.

Rumors say that it caused the deaths of a lighthouse keeper and his family in the 1920s, but it’s not documented.

3 Amazing Facts About Golden Lanceheads

  • One gram of their venom can cost more than one gram of gold.
  • Scientists say that their venom is 3-5 times more toxic than other lancehead species.
  • They are one of the few lanceheads that are at least partly arboreal.

Where to Find Golden Lanceheads

Golden lancehead snakes only live on one island off the coast of Brazil – Ila Queimada Grande, known to most of the world as Snake Island. They live in a variety of habitats on the island, from rocky hills to subtropical forests.

About Snake Island

Ila Queimada Grande, which translates as the Island of the Big burn, used to be connected to mainland Brazil, but at the end of the last ice age, the world’s sea levels rose and isolated it from the rest of South America. The animals trapped here suddenly had both an opportunity and a challenge.

For some reason, when the water levels rose, there weren’t any land predators or mammals. They had to change if they were to survive – and change they did!

While there weren’t any land mammals for prey, there were birds. Lots of birds. So the snakes took to the trees and developed a venom that takes them down quickly.

Fast forward 11,000 years, and you have a 106-acre island 30 miles off the coast of Brazil that is home to snakes, birds, insects, and little else. Golden lanceheads only live in the forested part, an area of about 63 acres.

Today, the only people allowed to visit the island are the Brazilian military, who maintain the lighthouse, and researchers with special permission from the Brazilian government.

Scientific Name

This snake’s scientific name describes both the type of snake and where they live. Bothrops is Greek and means pit face, while insular means island; fitting, as they live on an island.

Their common name, golden lancehead, refers to their head shape and color. These snakes have golden bellies and spearhead-shaped heads. Bothrops insularis, the sole species of known Golden Lancehead, is only found on Ilha da Queimada Grande, an island off the coast of So Paulo state in Brazil. An earlier French name for the genus, fer-de-lance, means the same, but scientists now apply it to only a couple of species.

Evolution and Origins

The Golden Lancehead, also known as Bothrops Insularis, is a venomous pit viper that is found exclusively on Ilha da Queimada Grande, an island located off the coast of São Paulo state in Brazil.

The population of Golden Lancehead snakes on Snake Island is estimated to be around 2,000 to 4,000 individuals, and since this island is the only known habitat for this species, the snakes have been classified as Critically Endangered on the IUCN Red List.

Additionally, this snake sometimes gets confused with the pit viper. So, here are a few differences: golden lanceheads are distinct from other pit vipers in terms of their size, venom, and appearance, as they are relatively small, measuring only 4 feet in length, have potent venom that can be lethal to humans, and are recognizable for their yellow skin.

Population and Conservation Status

Click to play on YouTube

The golden lancehead snakes have a population of between 2,000 and 4,000 on Snake Island. This is the only place in the world you’ll find these snakes, and in light of this fact, they’re on the IUCN Redlist as Critically Endangered.

At one point, people burned the vegetation on the island to try to kill off the snakes and start a banana plantation. Unfortunately for them, the snakes hid in crevices until the flames died down. The snake population suffered, and the areas that burned are growing back, but it may yet be decades before the forests recover completely.

Brazilian military maintains a lighthouse on the island, and they have removed a lot of the trees and vegetation where the snakes hide. This did some damage to the population, but it’s the poachers who are the biggest unknown.

Poachers and the $30,000 Catch

Some scientists believe that poachers are doing the most damage to the population. Golden lancehead snakes are so valuable in the illegal pet trade and scientific research that poachers visit the island illegally to try to capture and sell them.

One specimen can come with a paycheck of $10,000 to $30,000, depending upon the age and health. To some smugglers, that’s a worthy payoff for the risk of an agonizing death.

However, studies aren’t conclusive because snake populations are difficult to accurately observe. A study published in 2014 concluded that their primary challenges to survival are food and reproduction.

They observed that males seemed to have a higher survival rate than females and believe it may be due to the higher quantity of resources that females require for breeding.

Appearance and Description

golden lancehead

Golden lanceheads are pit vipers that have heat-sensing organs located between their nostrils and eyes.

These snakes measure between two and four feet as adults. There isn’t much data on juveniles; however, their closest relative, the yarara (B. jararaca), produces offspring that average about 12 inches long. So, this seems like a reasonable estimate.

They are slender snakes, and the golden lanceheads’ color ranges from yellowish to light golden brown with darker irregular markings along the length of their back. Their markings are mostly triangular, with somewhat squarish markings interspersed in between.

These snakes have a sharply angular head that is reminiscent of a spearhead (hence its name), and yellow-gold eyes with elliptical pupils.

Venom: How Dangerous are They?

This snake is one of the most venomous species in the world. While no one on record has ever died from a bite from a golden lancehead, scientists estimate that an untreated bite may carry a 7% fatality rate. They base this on the mortality rate for other lancehead species bites.

Golden lancehead snakes evolved a highly toxic and fast-acting venom. Some say that it melts human flesh, but this is most likely an exaggeration. However, according to research, it is up to 5% more toxic than that its mainland cousins.

Their venom contains hemotoxic venom that helps the snake digest their food. It causes pain and swelling around the bite, nausea and vomiting, blood in the vomit and urine, bruising, intestinal bleeding, kidney failure, brain hemorrhage, and severe death of muscular tissue. Some say that those bitten and envenomated by a golden lancehead snake could die within six hours.

golden lancehead

This is one of the most venomous snake species in the world. Although a golden lancehead bite has never been seen to result in death, scientists believe that an untreated bite may have a 7% fatality risk.

Scientific Research

Lancehead snake venom (Bothrops Atrox) has contributed to medicines for high blood pressure and clotting disorders.

Venom from this snake and other venomous snakes is valuable to scientists. Several medical advancements have come from research performed on snake venom. Researchers believe that this species holds even more promise for medical research.

Behavior and Humans

This snake eats primarily birds, but younger snakes may also eat smaller prey such as lizards or nestlings. Most often, golden lancehead snakes eat tyrant flycatchers, a passerine bird on the island. There’s some evidence, based on damaged tails and observed behavior, that the species uses some form of caudal luring to entice their prey close enough to strike.

Due to the isolated nature of the golden lancehead population, human interactions are exceedingly rare, and almost always intentional (either researchers or poachers).

Similar Animals

View all 261 animals that start with G

Sources

  1. Reptile Database / Accessed March 25, 2022
  2. The golden lancehead Bothrops insularis (Serpentes: Viperidae) relies on two seasonally plentiful bird species visiting its island habitat | Otavio A. V. Marques, Marcio Martins, Pedro F. Develey, Arthur Macarrão & Ivan Sazima / Published December 30, 2011 / Accessed March 25, 2022
  3. Population Dynamics of the Critically Endangered Golden Lancehead Pitviper, Bothrops insularis: Stability or Decline? | Murilo Guimarães, Roberto Munguía-Steyer, Paul F. Doherty J, Marcio Martins, Ricardo J. Sawaya / Published April 22, 2014 / Accessed March 25, 2022
Gail Baker Nelson

About the Author

Gail Baker Nelson

Gail Baker Nelson is a writer at A-Z Animals where she focuses on reptiles and dogs. Gail has been writing for over a decade and uses her experience training her dogs and keeping toads, lizards, and snakes in her work. A resident of Texas, Gail loves working with her three dogs and caring for her cat, and pet ball python.
Connect:

Thank you for reading! Have some feedback for us?


Golden Lancehead FAQs (Frequently Asked Questions)

These snakes only live on one small island off the coast of Brazil the locals call Ila Queimada Grande, which most people call Snake Island.