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Species Profile

Orange Baboon Tarantula

Pterinochilus murinus

Orange Baboon Tarantula: Web. Dash. Defend.
Audrey Snider-Bell/Shutterstock.com

Orange Baboon Tarantula Distribution

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Usambara Orange Baboon Tarantula (Pterinochus murinus).

At a Glance

Wild Species
Also Known As OBT, Baboon spider, African baboon tarantula, Orange baboon
Activity Nocturnal+
Lifespan 7 years
Status Not Evaluated
Did You Know?

The Orange Baboon Tarantula (Pterinochilus murinus) is an Old World tarantula-no urticating hairs-so it primarily relies on threat displays and biting for defense.

Scientific Classification

A fast, defensive Old World tarantula species widely known in the arachnid hobby as the “Orange Baboon Tarantula (OBT),” notable for its vivid orange coloration (in many morphs) and heavy webbing behavior.

Kingdom
Animalia
Phylum
Arthropoda
Class
Arachnida
Order
Araneae
Family
Theraphosidae
Genus
Pterinochilus
Species
murinus

Distinguishing Features

  • Often bright orange to orange-brown overall coloration (common in the hobby)
  • Old World tarantula: lacks urticating hairs and relies more on threat displays/biting
  • Notably fast and defensive temperament; prolific webber
  • Terrestrial/burrowing lifestyle with webbed retreat

Physical Measurements

Males and females differ in size

Length
4 in (4 in – 5 in)
5 in (4 in – 6 in)
Venomous

Appearance

Primary Colors
Secondary Colors
Skin Type Chitinous exoskeleton densely covered in tactile setae (no urticating hairs; Old World theraphosid). Heavy silk use creates sheet/funnel webbing over substrate and burrow entrances.
Distinctive Features
  • Common name: Orange Baboon Tarantula; introduce OBT only after full name in husbandry contexts.
  • Old World tarantula: lacks urticating hairs; primary defense is threat posture/rapid bite (behavior widely documented in captivity/field observations).
  • Origin: East Africa (records include Kenya and Tanzania; distribution per World Spider Catalog).
  • Lifestyle: terrestrial to fossorial; uses pre-existing voids/burrows and heavily reinforces with dense webbing.
  • Typical adult size reported in husbandry literature: ~12-15 cm legspan; robust, long-legged build (peer-reviewed morphometrics vary by locality and are less consistently published).
  • Lifespan (commonly reported in captivity): females ~10-15+ years; males ~3-5 years with much shorter post-maturity survival (values vary with temperature/feeding).
  • Distinctive posture: very fast, defensive "bolt-and-bite" reputation; not considered docile or beginner-friendly.
  • Strong scopulae on tarsi/metatarsi aid climbing despite primarily terrestrial habits; can climb smooth surfaces unexpectedly.

Sexual Dimorphism

Females are larger-bodied and longer-lived, with thicker legs and a more robust abdomen. Mature males are leggier and slimmer, develop palpal bulbs and tibial apophyses, and typically live only months to a few years after maturing.

  • Slender build with proportionally longer legs; often slightly duller orange/tan.
  • Mature palpal bulbs present on pedipalps (sperm transfer organs).
  • Tibial apophyses (mating hooks) on the first pair of legs at maturity.
  • Shorter overall lifespan; rapid wandering behavior when searching for females.
  • More robust carapace/abdomen and thicker legs; generally heavier-bodied.
  • Larger maximum size and substantially longer lifespan.
  • No palpal bulbs or tibial apophyses; retains stout, powerful stance.
  • More likely to maintain and defend a webbed burrow/retreat long-term.

Did You Know?

The Orange Baboon Tarantula (Pterinochilus murinus) is an Old World tarantula-no urticating hairs-so it primarily relies on threat displays and biting for defense.

Adult females commonly reach about 12-15 cm legspan, with a stout body length often around 4-6 cm; males are typically slimmer and shorter-lived.

It's famous for "webbing everything": silk is used not just for the burrow but for trip-lines, sheet-webbing, and anchoring retreats across the enclosure.

Color varies by locality/morph (orange to more brown/olive), but the hobby common name "Orange Baboon Tarantula" usually refers specifically to P. murinus.

Females can live roughly ~10-15 years in captivity under good care; males often live ~3-4 years total and may only survive a short time after maturity.

The species was described scientifically by Reginald Innes Pocock in 1897, and it has become one of the most recognizable African theraphosids in the arachnid hobby.

Unique Adaptations

  • Old World defense strategy: lacks urticating hairs, so it evolved a greater reliance on speed, intimidating displays, and a medically significant bite (typically intense local pain; serious outcomes are uncommon but risk depends on circumstances and individual reaction).
  • "Sensor web" architecture: extensive silk acts like a vibration-sensing net, letting the spider detect prey or threats without leaving the safety of the retreat.
  • Arid-adapted lifestyle: native to seasonally dry East African habitats; burrowing and retreat-building help buffer heat and dehydration by creating a more stable microclimate.
  • Cryptic retreat engineering: silk reinforces soil and leaf-litter structures, stabilizing burrows and creating multiple exits/turns that improve escape options.
  • Robust, fast locomotion: powerful legs and rapid acceleration suit a ground-dwelling hunter that must either seize prey instantly or retreat quickly.

Interesting Behaviors

  • Heavy, persistent webbing: builds dense silk carpets and tubes that extend well beyond the burrow entrance, functioning as both retreat structure and vibration "alarm system."
  • Terrestrial burrower: typically establishes a silk-lined burrow under cover (cork bark/rocks/roots) and expands it over time rather than living exposed.
  • High-speed startle response: often "bolts" to cover when disturbed, but may pivot rapidly into a defensive stance if escape feels blocked.
  • Defensive threat posture: raises front legs and exposes fangs; may deliver fast defensive strikes at close range (a hallmark Old World temperament in captivity).
  • Mostly crepuscular/nocturnal activity patterns: tends to stay in retreat by day and patrol or rework webbing more actively in low light.
  • Opportunistic ambush feeding: waits at the burrow mouth or on webbing for vibrations, then lunges to seize prey quickly.

Cultural Significance

Called the Orange baboon tarantula (Pterinochilus murinus), this Old World tarantula is known in Africa as a "baboon spider" because its leg hair looks like a baboon's fingers. Hobbyists admire its color and webbing, and note its speed and defensiveness.

Myths & Legends

Anansi the Spider (Akan folklore, Ghana) is a West African set of tales where Anansi, a clever spider, uses tricks and stories to outwit stronger animals. Not species-specific, but shapes how people view spiders.

In the Arachne myth, her weaving contest with Athena ends with her changed into a spider, tying spiders to art, pride, and weaving—a story that fits web-building species well.

In southern African English, people call Pterinochilus murinus a 'baboon spider' because its hairy legs look like a baboon's fingers. This story shows up in local nature talk and field tales.

Conservation Status

NE Not Evaluated

Has not yet been evaluated against the criteria.

Population Unknown

Life Cycle

Birth 120 spiderlings
Lifespan 7 years

Lifespan

In the Wild
2–12 years
In Captivity
3–15 years

Reproduction

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

Solitary; mature males wander to locate females and may mate with multiple females. Females can accept more than one male and store sperm before producing an egg sac; mating is brief, with no pair bond and possible sexual cannibalism.

Behavior & Ecology

Social Solitary Group: 1
Activity Nocturnal, Crepuscular
Diet Insectivore Cockroaches (Blattodea), when available (highly accepted prey in captivity; wild prey is presumed similar-sized ground insects in savanna/scrub habitats).

Temperament

Primarily solitary, highly territorial around the retreat; intruders often met with threat displays or bites.
Fast, defensive Old World theraphosid; typically relies on threat posture and rapid strikes rather than urticating hairs (Theraphosidae Old World condition).
Constructs a silk-lined burrow or bolt-hole retreat and often lays extensive webbing around the entrance.
Ambush-oriented sit-and-wait predator from a webbed retreat; will also actively rush prey at short range.
Cannibalism risk is high with co-housing (especially juveniles); communal stability is not characteristic of this species.
Longevity: robust, peer-reviewed wild lifespan estimates for P. murinus are not established; captive-keeping records commonly report females living ~10-15 years and males ~3-4 years after maturity (non-peer-reviewed husbandry datasets).
Body size: standardized, species-wide adult morphometrics are inconsistently reported in primary literature; hobby measurements commonly cite ~10-13 cm legspan for adults (non-peer-reviewed).

Communication

Seismic/vibratory signaling via substrate and web Courtship drumming/tapping), typical of theraphosids (e.g., Foelix, 2011
Chemical cues/pheromones: males follow female silk and contact cues to locate receptive females Foelix, 2011
Tactile signaling during mating: male palpal insertion sequence coordinated with leg contact and female posture.
Visual threat display: raised anterior legs, exposed chelicerae; functions as deterrent at close range.

Habitat

Biomes:
Savanna Tropical Dry Forest Desert Hot
Terrain:
Plains Rocky Sandy Hilly
Elevation: Up to 4921 ft 3 in

Ecological Role

Generalist ground-level arthropod predator (mesopredator) in East African savanna/scrub ecosystems; also serves as prey for vertebrate and invertebrate predators.

Regulates populations of ground-dwelling insects and other arthropods via predation (top-down control) Contributes to local food webs as prey for birds, reptiles, small mammals, and spider-hunting wasps Burrowing/retreat construction can contribute to soil turnover and microhabitat structuring at small spatial scales

Diet Details

Main Prey:
Orthopterans Cockroach Beetles Lepidopteran larvae and adults Termites Spiders and small ground-dwelling arthropods

Human Interaction

Domestication Status

Wild

Pterinochilus murinus (Orange Baboon Tarantula) is a wild, not domesticated Old World tarantula named in 1897. Native to arid East Africa, it lives in burrows and uses silk for shelters and trip-lines. People often fear it locally, keep it in the pet trade (bright orange morphs), and study its venom.

Danger Level

High
  • Defensive biting risk: P. murinus is widely regarded as very fast and readily defensive; it often stands its ground, threat-postures, and may bite rather than flee (a common pattern in Old World theraphosids that lack urticating hairs).
  • Venom effects: while not known to be lethal to healthy adults, Old World theraphosid bites can cause severe immediate pain and systemic symptoms (e.g., cramping/spasms, sweating, nausea, elevated heart rate) in some cases; severity varies by individual and circumstances. Medical evaluation is advised after significant symptoms, and emergency care is warranted for breathing difficulty, chest pain, or anaphylaxis.
  • Allergic reactions: as with any spider bite/animal exposure, sensitized individuals may develop significant allergic responses.
  • Secondary injury risk: sudden startle response during an escape/defensive event can lead to falls, dropped enclosures, or lacerations; the species' speed increases handling/transfer risk.
  • Husbandry-linked exposure: rehousing and maintenance are the highest-risk interaction points due to rapid bolting and defensive posturing combined with heavy webbing that obscures the animal's position.

As a Pet

Not Suitable as Pet

Legality: Orange baboon tarantula (Pterinochilus murinus) is usually legal in places without invertebrate rules, but laws vary. Some areas ban or need permits; always check local, shipping, and import rules.

Care Level: Expert Only

Purchase Cost: $30 - $150
Lifetime Cost: $200 - $1,000

Economic Value

Uses:
Pet trade (captive keeping and breeding) Education/display (zoos, outreach programs) Scientific/biomedical research inputs (venom screening; comparative arachnology)
Products:
  • Live specimens (spiderlings/juveniles/adults) sold in the arachnid hobby
  • Captive-breeding services/stock
  • Educational demonstrations and exhibits involving live animals
  • Research samples (e.g., venom for screening in specialized labs, where legally and ethically sourced)

Relationships

Related Species 7

Pterinochilus chordatus Pterinochilus chordatus Shared Genus
Lugardi baboon tarantula Pterinochilus lugardi Shared Genus
Simon's baboon tarantula Pterinochilus simoni Shared Genus
Voracious baboon tarantula Pterinochilus vorax Shared Genus
King baboon spider Pelinobius muticus Shared Family
Cameroon red baboon tarantula Hysterocrates gigas Shared Family
Featherleg baboon tarantula Stromatopelma calceatum Shared Family

Ecological Equivalents 4

Animals that fill a similar ecological role in their ecosystem

King baboon spider Pelinobius muticus Pterinochilus murinus is an East African Old World theraphosid that lives in ground burrows, feeds on similar invertebrates, and displays rapid threat and feeding responses, relying on burrow defense rather than urticating hairs.
Horned baboon tarantula Ceratogyrus darlingi Occupies the "baboon spider" niche in southern Africa: a terrestrial retreat-builder that reinforces a burrow or cover object with silk and ambushes passing insects. Shares the Old World defensive strategy (lacks urticating hairs) and strongly relies on shelter and webbing for security.
Featherleg baboon tarantula Stromatopelma calceatum Often compared with Poecilotheria murinus: both are fast Old World theraphosid tarantulas, highly defensive, and possess strong venom. Stromatopelma calceatum is mainly arboreal, feeds on insects and other arthropods, and uses retreats heavily lined with silk.
Cameroon red baboon tarantula Hysterocrates gigas A large African theraphosid that, like P. murinus, uses a secure retreat and waits to catch ground arthropods. Hysterocrates gigas prefers humid areas and deeper burrows, but both are nocturnal ground-ambush predators.

The orange baboon tarantula is both orange and ornery.

The orange baboon tarantula (OBT) is covered in bright orange bristles. Their faces resemble furry, orange baboons. OBT’s, as they are sometimes referred to, are known to have an ornery disposition and can act aggressively. They can grow to be similar in size to the Mexican Red Knee with a body around three inches and a leg span of five to six inches. These are Old World tarantulas and live in central and southern Africa. Orange baboon tarantulas are kept as pets but not recommended for beginners.  

Amazing Facts

  • They are covered in tiny orange bristles.
  • They can grow to be two to three inches long with a leg span of five to six inches.
  • Their temperament is a bit grumpy with a tendency to rear up in a threat posture.
  • Orange baboon tarantulas are venomous and their bites are harmful to humans.
  • They are native to central and southern Africa.

Scientific Name

The scientific name of the orange baboon tarantula is Pterinochilus murinus. They are commonly called OBTs for short which pet hobbyists sometime comically refer to as the “orange bitey thing” due to their aggressive nature. The latin word murinus means “grey-mouse-colored” and they are sometimes called another nickname Pterror (silent “P”), a play on their scientific name, Pterinochilus.

Appearance

The orange baboon tarantula is rightfully named due to its furry coat of orange hair. Some tarantulas have orange legs but this one is completely covered in orange bristles called setae. The other remarkable coloration is the bottom of their feet which are an iridescent blue-green. You can see these when the tarantula rears waving its front legs and pedipalps in a threat position. They have two larger black, beady eyes that are prominent beside its six smaller eyes.

The females are a bit larger than the males with a body that is two to three inches and stout. Their leg span is five to six inches, which is about the length of a cell phone. They have eight segmented legs with lighter colored knee joints. Two appendages on the front of their body look like more legs but they are a tad shorter, these are the pedipalps. Their abdomens are oblong and have darker markings with the spinnerets at their end.

Usambara Orange Baboon Tarantula (Pterinochus murinus).

The orange baboon tarantula features orange bristles on its body and a bit of a cranky temperament.

Behavior

The most remarkable behavior of the OBT is that they are quick to react with a threat pose. The threat pose is observed when a tarantula rears up and waves its front appendages and shows its fang. This aggressive stance sends a clear message to the predator to back off. If the orange baboon tarantula still feels threatened, it is quick to attack and bite. This is how it received its nickname “orange bitey thing”. Their bites are venomous and harmful to humans, so anyone who is bitten should seek immediate medical attention.

In the wild, this defense mechanism serves them well. They may begin by retreating or fleeing before going into a threat pose, but they are considered more aggressive than other tarantulas. As a terrestrial and semi-arboreal animal they have to be aware of predators both on the ground and in the surrounding trees. As an Old World species they do not have urticating hairs to flick at an approaching threat.

They spend their days in their burrows or in a large web tunnel that they make on the ground or in bushes/tree’s lower branches. At night they come out to try to find food such as insects, crickets, roaches, worms, small lizards or frogs.

Habitat

Orange baboon tarantulas are from central and southern Africa. There are populations spread out in many countries. Some of the countries they can be found in are Kenya, Zambia, Angola, Congo, Zimbabwe and Tanzania.

They are both terrestrial and semi-arboreal making webbed tunnels on the ground and in trees, but they will also make burrows to hide in during the day. Sometimes they make their own burrows while other times the take over the burrow of an abandoned creature. They spin a webbed “door” to cover the entrance of their burrow as protection.

The climate in Africa where they live is warm and very humid. In the wild, they adjust to the weather by staying hidden during the day and moving deeper into their burrow when needed to find cooler temperatures. In captivity, they should be kept in an enclosure that is 75°-78° with a higher humidity of 70-80%. Both terrestrial and arboreal surroundings should be available to this species when in captivity.

Predators and Threats

The orange baboon tarantula has similar predators as other spider species. Predators include other spiders, lizards, snakes and birds. OBTs are not afraid to take on predators that are a little bigger than themselves. They can actually turn the tables and attack and kill animals bigger than themselves. Sometimes, they will not even give the threat pose, and instead, quickly bite their threatener, releasing their venom.

During the day these tarantulas hide from predators in a deep burrow in the ground or safely in their webbed tunnels. At night they use the hairs on their legs to sense movement around them, warning them of trouble.

What Eats Orange Baboon Tarantulas?

The animals that eat orange baboon tarantulas are snakes, lizards, birds and larger spiders. Tarantula hawks are one of its biggest, and most vicious, predators. These creatures are actually not a hawks but are large, blue and orange wasps. They go after tarantulas by attacking and stinging them, which paralyzes the tarantula but doesn’t kill it. They then inject one egg into their abdomen and bury them alive. When the wasp larvae hatches it feeds on the still living tarantula.

What Do Orange Baboon Tarantulas Eat?

Orange baboon tarantulas eat insects, frogs, lizards, small birds, and small mice. They hunt at night by waiting just inside the entrance of their burrow. When they feel the movement of a prey passing by, they lurch at it and subdue it with their pedipalps using their fangs to stabilize it. They quickly inject it with venom and use their web to ball it up. OBTs use their straw-like mouth to suck up the liquefied prey.

In captivity they are voracious eaters and aggressively attack food put in their enclosures. This behavior is one of the reason pet hobbyists enjoy watching this unique creature.

What is the Conservation Status?

Orange baboon tarantulas are not listed by the IUCN as a threatened animal. They have populations in many different countries in central and southern Africa so their population seems to be healthy.

Reproduction, Babies, and Lifespan

You might think that a grumpy, aggressive tarantula might have a hard time finding a mate; however, you see this aggressiveness in both males and females. This might make it seem even harder! But they tend to put their differences aside for the sake of procreating because they continue to reproduce. Like other tarantula species, the females do have a tendency to eat the males right after mating, so there is still that!

Female orange baboon tarantulas lay around 50-100 eggs. She forms an eggs sac that she hides in her burrow until the eggs are ready to hatch. The mother turns the sack periodically, assisting in fertilization. Can you imagine 100 grumpy baby spiders all running around? Well, they don’t stick around for long and will depart to find a new home of their own shortly after hatching.

The life span of the orange baboon tarantula is quite different between males and females. Males only live to be three to four years old, and females live 12-15 years. If males don’t get eaten by their mate, that is!

Population

Due to the range and habitat of the orange baboon tarantulas, it remains uncertain what their exact population is. They are not listed by the International Union for Conservation of Nature (IUCN), which means they are not considered threatened, and they have recorded populations in many countries in central and south Africa.

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Sources

  1. Tarantulafriendly.com / Accessed November 3, 2022
  2. eol.org / Accessed November 2, 2022
  3. The Tarantula Collective / Accessed November 2, 2022
Cindy Rasmussen

About the Author

Cindy Rasmussen

I'm a Wildlife Conservation Author and Journalist, raising awareness about conservation by teaching others about the amazing animals we share the planet with. I graduated from the University of Minnesota-Morris with a degree in Elementary Education and I am a former teacher. When I am not writing I love going to my kids' soccer games, watching movies, taking on DIY projects and running with our giant Labradoodle "Tango".
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Orange Baboon Tarantula FAQs (Frequently Asked Questions)

They are venomous, and they have a reputation for biting! Their venom is harmful to humans but has not been recorded as fatal.