Goliath bird-eating spider (Theraphosa blondi)
|Also known as:||giant bird-eating spider, giant bird-eating tarantula, giant tarantula, goliath birdeater, goliath bird-eater, goliath tarantula|
|Size||Body length: up to 11.9 cm (2)|
Leg span: up to 28 cm (3)
|Weight||up to 175 g (2) (4)|
- The goliath bird-eating spider is the world’s heaviest spider, and also one of the largest in terms of its leg span.
- Despite the goliath bird-eating spider’s name, birds do not make up much of its diet.
- The goliath bird-eating spider kills its prey with venom injected through its huge fangs, which are nearly an inch in length.
- The goliath bird-eating spider can flick irritating hairs from its abdomen to deter attackers.
The goliath bird-eating spider has yet to be classified by the IUCN.
Also known as the goliath or giant tarantula, the goliath bird-eating spider (Theraphosa blondi) is the heaviest spider in the world (3) (4). It is also one of the largest (3) (5) (6), coming a close second to the giant huntsman spider (Heteropoda maxima) in terms of its leg span (7).
The goliath bird-eating spider is generally dark to light brown in colour (3) (8), and like other tarantulas it is covered in a thick layer of hairs, which are very sensitive to movement and vibrations (5).
The goliath bird-eating spider is found in rainforests from southern Venezuela east to Guyana, Suriname, French Guiana and north-eastern Brazil (3) (4) (6) (9).
The goliath bird-eating spider is reported to inhabit undisturbed rainforest (4) (6), and requires areas with high humidity (4). This species lives in silk-lined burrows (4) (5), either digging one itself or taking over an abandoned rodent burrow (5). It can also be found under fallen logs and in cavities under rocks (4).
The common name of the goliath bird-eating spider is somewhat misleading, as this large tarantula does not usually eat birds (4) (6). Instead, its diet consists largely of insects and other invertebrates, including earthworms (3) (4) (6) (10), although it will also catch small vertebrates such as lizards, frogs and small mammals (3) (4) (6) (11).
The goliath bird-eating spider has quite poor eyesight, and instead detects prey mainly by sensing vibrations in the ground. When prey is detected, the spider will pounce on it and inject it with venom using its two-centimetre-long fangs (4). Like other burrow-dwelling tarantulas, the goliath bird-eating spider is mostly active at night, and it tends to hunt within a fairly limited area around its burrow (5).
Despite its formidable appearance, the goliath bird-eating spider is not generally a threat to humans, with its bite reportedly being little worse than a wasp sting (4) (7). This species uses a number of other methods to defend itself against potential predators. For example, it may attempt to scare off an attacker by rubbing together bristles on its first and second pair of legs, producing a hissing sound (4) (5) (12) (13). It also possesses barbed, irritating hairs on its abdomen, which it can flick at an attacker, potentially causing severe irritation to the skin, eyes, nose and mouth. As a further defence strategy, the goliath bird-eating spider may also rear up on its hind legs, showing its large fangs (4) (5).
The goliath bird-eating spider is generally solitary, and individuals only come together to mate (5). Adult female goliath bird-eating spiders lay around 50 to 150 eggs in a large silk sac (4), which is guarded aggressively (6). The female of this species has been known to add irritating hairs from its abdomen to the silk of the egg sac (4), which may help to protect the developing young from parasitic flies (6) (9).
The female goliath bird-eating spider starts to enlarge her burrow in the two weeks before the eggs are laid. Just before egg laying occurs, she seals the burrow with a layer of thick, whitish silk (9). The female guards the egg sac within the burrow until the young spiderlings emerge, around one to two months later (4) (5) (6), and she does not feed during this time (3).
The young goliath bird-eating spiders remain in the female’s burrow until after their first moult, and then disperse (3) (5). This large spider takes around two to three years to reach maturity (3) (4). Female goliath bird-eating spiders can potentially live for up to 20 years, but males usually only live for around 3 to 6 years (4).
Like other large tarantulas, the goliath bird-eating spider is highly sought-after in the pet trade (8) (9), despite its apparently aggressive nature (6) (9). Unfortunately, this results in many individuals being taken from the wild, and for each one that reaches the market it is estimated that up to nine more may die during capture and transport (3).
The goliath bird-eating spider is also thought to be under threat from the destruction of its rainforest habitat (4). In addition, this species is sometimes caught and eaten by indigenous people (7).
There are no specific conservation measures currently known to be in place for the wild populations of the goliath bird-eating spider. However, this species is of interest to zoos and other collections, and the establishment of captive breeding programmes has been recommended to reduce the collection pressure on wild populations. Captive breeding may also help scientists to find out more about this impressive spider’s biology and breeding behaviour (6).
Find out more about the goliath bird-eating spider:
BBC Nature - Goliath bird-eating spider:
Natural History Museum - Theraphosa blondi (Goliath bird-eating spider):
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- Abdomen: in arthropods (crustaceans, insects and arachnids) the abdomen is the hind region of the body, which is usually segmented to a degree (but not visibly in most spiders).
- Invertebrates: animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.
- Moult: in insects and other arthropods, a stage of growth whereby the hard outer layer of the body (the exoskeleton) is shed and the body becomes larger.
- Parasitic: describes an organism that derives its food from, and lives in or on, another living organism at the host’s expense.
- Vertebrates: animals with a backbone, including mammals, birds, reptiles, amphibians and fish.
Species 2000 and ITIS Catalogue of Life(August, 2013)
Natural History Museum (2011) World’s heaviest spider title challenged at Museum. Natural History Museum News, 15 July. Available at:
Marwell Wildlife: Animal Encyclopaedia - Goliath bird-eating spider (August, 2013)
Natural History Museum - Theraphosa blondi (Goliath bird-eating spider) (August, 2013)
- Hillyard, P. (2007) The Private Life of Spiders. New Holland Publishers (UK) Ltd, London.
- Saul-Gershenz, L. (1996) Laboratory culture techniques for the goliath tarantula Theraphosa blondi (Latreille, 1804) and the Mexican red knee tarantula, Brachypelma smithi (Araneae: Theraphosidae). AAZPA Annual Conference Proceedings: 773-777.
BBC Nature - Goliath bird-eating spider (August, 2013)
- Lewbart, G.A. (2012) Invertebrate Medicine. Second Edition. John Wiley & Sons Ltd, Chichester.
- Striffler, B.F. (2005) Life history of goliath birdeaters - Theraphosa apophysis and Theraphosa blondi (Araneae, Theraphosidae, Theraphosinae). Journal of the British Tarantula Society, 21(1): 26-33.
- Nyffeler, M., Moor, H. and Foelix, R.F. (2001) Spiders feeding on earthworms. The Journal of Arachnology, 29: 119-124.
- Menin, M., Rodrigues, D.J. and Azevedo, C.S. (2005) Predation on amphibians by spiders (Arachnida, Araneae) in the Neotropical region. Phyllomedusa, 4(1): 39-47.
- Herberstein, M.E. (Ed.) (2011) Spider Behaviour: Flexibility and Versatility. Cambridge University Press, Cambridge.
- Marshall, S.D., Thoms, E.M. and Uetz, G.W. (1995) Setal entanglement: an undescribed method of stridulation by a neotropical tarantula (Araneae: Theraphosidae). Journal of Zoology, 235(4): 587-595.