Arizona is home to the desert tarantula — a large, docile spider that many residents have learned to coexist with. But in the rainforests of northern South America lives a tarantula that makes the desert tarantula look like a house spider. Theraphosa blondi, the Goliath birdeater, holds the Guinness World Record for the world's largest spider by mass and leg span. With a leg span of up to 28cm (11 inches) and fangs 2–4cm long, it is a creature of a different scale entirely.
Record-Breaking Size
The largest confirmed Goliath birdeater specimen had a leg span of 28cm (11 inches) and weighed 170 grams (6 ounces) — roughly the weight of a baseball. Females are substantially larger than males and live dramatically longer: females survive 15–25 years in the wild, while males typically die within 3–6 years, often shortly after their first mating.
The body alone — excluding legs — can reach 13cm (5 inches). The spider is covered in dense, dark brown to reddish-brown hair. When it walks across a hard surface, you can hear its footsteps.
Does It Actually Eat Birds?
The name "birdeater" comes from an 18th-century copper engraving by German naturalist Maria Sibylla Merian, who depicted a large spider consuming a hummingbird in Suriname. The image caused a sensation in Europe and the name stuck — but it is somewhat misleading.
In practice, the Goliath birdeater's diet consists primarily of large insects, earthworms, frogs, lizards, and small rodents. It is an ambush predator that waits at the entrance of its burrow for prey to wander within striking distance. Bird predation does occur — particularly of ground-nesting birds and nestlings — but it is opportunistic and not a regular part of the diet. The spider is more accurately described as a generalist predator of anything it can overpower.
Defenses: Fangs, Venom, and Urticating Hairs
The Goliath birdeater has three primary defenses, each remarkable in its own right.
Fangs: At 2–4cm long, the fangs are large enough to cause significant puncture wounds. They strike downward with considerable force. However, the venom is relatively mild — comparable to a wasp sting — and not considered medically significant to healthy adults. There are no confirmed human fatalities from Goliath birdeater bites.
Urticating hairs: Like most New World tarantulas, the Goliath birdeater has specialized barbed hairs on its abdomen. When threatened, it rapidly rubs its hind legs against its abdomen, launching a cloud of these hairs toward the threat. The hairs embed in skin and mucous membranes, causing intense itching, redness, and swelling. Contact with the eyes can cause serious irritation and temporary vision impairment. This is the spider's primary defense against most predators.
Stridulation: The Goliath birdeater can produce an audible hissing sound by rubbing its leg segments together — a warning display audible from several meters away.
Habitat and Range
The Goliath birdeater is found in the rainforests of northern South America — primarily Venezuela, Brazil, Guyana, Suriname, and French Guiana. It lives in deep burrows in the forest floor, often in swampy or marshy areas near water. It is strictly nocturnal, emerging after dark to hunt.
It requires high humidity and warm temperatures year-round. It cannot survive in Arizona's dry desert climate. The closest relative found in the American Southwest is the desert tarantula (Aphonopelma chalcodes), which is far smaller and entirely harmless.
The Goliath Birdeater as Food
In parts of Venezuela and Brazil, the Goliath birdeater is considered a delicacy by indigenous communities. The spider is roasted over an open fire, which burns off the urticating hairs. The meat — primarily in the abdomen and legs — is described as similar to shrimp in texture and flavor. It is a significant protein source in some remote communities.
Arizona's Own Giant: The Desert Tarantula
Arizona's desert tarantula (Aphonopelma chalcodes) reaches a leg span of about 10–12cm — impressive by North American standards, but roughly half the size of the Goliath birdeater. Like its South American cousin, it is docile, slow to bite, and its venom is mild. Male desert tarantulas are commonly seen crossing roads in late summer and fall during their mating season — a sight that surprises many Arizona newcomers but poses no danger.
Frequently Asked Questions
How big is the Goliath birdeater?
The Goliath birdeater holds the Guinness World Record for largest spider by mass and leg span. The largest confirmed specimen had a leg span of 28cm (11 inches) and weighed 170g (6 oz). Females live 15–25 years; males only 3–6 years.
Does the Goliath birdeater actually eat birds?
Rarely. The name comes from an 18th-century engraving showing a large spider eating a hummingbird. In practice, it primarily eats large insects, earthworms, frogs, lizards, and small rodents. Bird predation is opportunistic and uncommon.
Is the Goliath birdeater dangerous to humans?
Its venom is relatively mild — comparable to a wasp sting — and not medically significant to healthy adults. However, its fangs are 2–4cm long and can cause significant puncture wounds. Its primary defense is urticating hairs that cause intense skin and eye irritation.
Where does the Goliath birdeater live?
It is found in the rainforests of northern South America — primarily Venezuela, Brazil, Guyana, Suriname, and French Guiana. It lives in deep burrows in the forest floor, emerging at night to hunt.
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