The natural world is home to many creatures, from the largest mammals to the largest insects. This fascination with scale extends to the world of spiders, where one species stands out for its remarkable size. The Goliath Birdeater holds the title as the largest known spider.
Meet the Goliath Birdeater
The Goliath Birdeater (Theraphosa blondi) is the world’s largest spider. This tarantula typically appears in shades of russet brown to black, covered in dense, hairy bristles, giving it a robust appearance. Distinct spines are also visible on its third and fourth pairs of legs. Its name “birdeater” originated from an 18th-century engraving depicting a tarantula consuming a hummingbird, leading to the entire genus being labeled as such. Despite its common name, birds are not a primary part of its diet.
Unpacking Its Impressive Dimensions
The Goliath Birdeater is the largest spider by mass and body length. It can weigh up to 175 grams (6.2 ounces), comparable to a billiards ball or hockey puck. Its body alone can reach lengths of up to 13 centimeters (5 inches), roughly the size of a human fist. With legs fully extended, its leg span can reach 30 centimeters (12 inches), similar to a dinner plate.
While the Goliath Birdeater is the heaviest and has the largest body, the giant huntsman spider can occasionally exceed its leg span. However, Theraphosa blondi’s overall dimensions solidify its position as the world’s largest spider.
Life in the Rainforest
The Goliath Birdeater is native to the humid rainforests of northern South America, found in countries like Venezuela, northern Brazil, Guyana, French Guiana, and Suriname. These spiders often inhabit deep burrows under rocks, roots, or in swampy areas. As nocturnal predators, they spend daylight hours concealed, emerging at night to hunt.
Their diet primarily consists of insects, earthworms, frogs, and toads. They are opportunistic and will prey on small mammals like rodents and bats, or reptiles such as lizards and snakes.
While their fangs are up to 2.5 centimeters (1 inch) long, their venom is not considered lethal to humans, with a bite often compared to a wasp sting. When threatened, the Goliath Birdeater has several defense mechanisms, including rubbing bristles on its legs to release irritating urticating hairs, and producing a hissing sound by stridulation that can be heard up to 4.5 meters (15 feet) away. They rely on vibrations detected by their sensitive body hairs to navigate and locate prey, as their vision is poor.