Meet the Giant Bird-Eating Spider

The aptly named Goliath tarantula is the world’s largest spider. With the terrifying nickname “bird-eating spider,” the Goliath tarantula may sound like something out of a nightmare. However, this spider is not only misunderstood, but it also plays an important role in its ecosystem. Here’s everything you need to know about the incredible giant bird-eating spider of the South American rainforest.

The Size and Physiology of the World’s Largest Spider

The Goliath bird-eating tarantula (Theraphosa blondi) is recognized as the world’s largest spider species by mass and body length. This spider weighs 6 ounces and has a body length of 4.75 inches. Its maximum leg span is about 11 inches.

Females are typically larger than males and have significantly longer lifespans. While males only live 3-6 years, a female Goliath tarantula can live up to 20 years in the wild. However, the tarantula has an exoskeleton that it must shed in order to grow. Spiders go through 5-6 molts in their first year alone, and it takes 2-3 years for them to reach maturity.

The Goliath Bird-Eating Tarantula Habitat

This species of spider can be found along the Amazon in South America. The dense vegetation of the rainforest offers boundless opportunities for camouflage and for hunting prey. These spiders will often commandeer existing burrows of small mammals to use as their nests and as ambush points.

Despite the spider’s large size, the forest floor allows them to blend into the environment. If no existing burrows are available, these spiders will dig their own in the soft soil. They then use their silk to line their burrows.

How the “Bird-Eating Spider” Got Its Name

The Goliath bird-eating tarantula is believed to have earned its unique moniker not based on documented fact, but due to the interpretation of a piece of art. Some sources note that the spider was named for an 18th-century engraving of a different tarantula devouring a hummingbird. It was created by German naturalist and artist Maria Sibylla Merian. Despite scientists’ rebuttals that this spider rarely, if ever, feeds on birds, the name stuck. In fact, all members of the Theraphosa genus share the name “bird-eater.”

While this tarantula is certainly capable of catching a bird, it does most of its hunting on the forest floor. The spiders may eat birds’ eggs or a young bird that has fallen from a nest, but they typically eat insects, frogs, bats, small reptiles, and mice. However, if any creature even slightly smaller than this tarantula comes within reach, it will likely become prey.

Defensive Abilities

The eight eyes of this species are more intimidating in appearance than they are useful. Nearly blind, this tarantula is also incapable of smelling or hearing its prospective prey. Instead, they make use of the long hairs that line their legs. Similar to the way a cat’s whiskers work, these hairs sense vibrations in the air and transmit them to the spider as surprisingly sophisticated data. These hairs provide the spider with a greater understanding of its surroundings without revealing its presence to either predators or prey.

Those bristly hairs also function as defensive tools. When threatened, the spider will rub its legs together, which makes a hissing sound that can be heard from around 15 feet away. The hairs have stinging barbs on the ends that the tarantula can fire like missiles into the face of any predator that comes too close.

Hunting Habits

Goliath bird-eating tarantulas don’t spin webs to trap prey. Instead, these nocturnal spiders leave their underground burrows to hunt. The spider’s inch-long fangs are hollow, serving as syringes that inject toxins directly into the bloodstream of its prey. These toxins begin to liquefy the prey from the inside out. The spider then drags the dying prey back to its burrow to consume it.

While the Goliath spider will bear its fangs as a threat when cornered by humans, they are not generally dangerous. These spiders only attack in self-defense and will generally not inject toxins when they bite. In instances where humans have been bitten, the pain is said to be similar in severity to a wasp sting.

Social Behaviors

Goliath spiders live solitary lives except during periods of mating. While it’s common for female tarantulas to devour males after mating, that’s not the case with the Goliath tarantula. Although they may not be eaten, the males naturally tend to expire shortly after reaching sexual maturity. They typically die a few months after passing on their genetic material.

A female will lay between 50 and 200 eggs, but they’re more hands-on mothers than other spiders. After laying the eggs, she’ll simply wrap them up into a ball and carry them with her wherever she goes. A full sac of these eggs can reach roughly the size of a tennis ball. As noted earlier, the young go through multiple molts before reaching full size. It will take two to three years for them to reach their nearly foot-long leg span as fully mature adults.