A species that incites dread in the heart of arachnophobes, the Goliath birdeater (Theraphosa blondi) is the largest arachnid in the world by both mass and size. Found in the northern regions of South America, this mighty tarantula lives in the rainforest where it hunts a varied array of prey. Despite their name, the Goliath birdeater rarely preys on birds (disappointing I know) but will usually feed on other large arthropods, worms, rodents, and amphibians.
Goliath birdeaters have a rather gruesome hunting method. After choosing a suitable target, they will pounce and pierce them with their long fangs, injecting venom and killing them. Next, they will take their meal back to their burrow. After liquefying their victim’s insides, like most spiders, they will now enjoy the fruits of their labour. Although this sounds alarming, the Goliath birdeater’s venom is relatively mild – comparable to a wasp’s sting – and they only bite humans in self-defence.
These arachnids have evolved an ingenious deterrence against potential attackers. When threatened, they will rub their abdomen with their hind legs, shooting tiny, barbed hairs from their body. These hairs serve as a severe irritant to the skin, eyes and respiratory tract; they are known as urticating hairs. Highly effective, this defence mechanism quickly sends attackers running.
Females have a lifespan of 15 to 25 years, whilst males only live for 3 to 6 years as they die shortly after mating. The males’ fate is actually far more pleasant than the usual spider relationships where the female eats the male during mating. Following copulation, female Goliath birdeaters will spin a web, lay 50 to 200 eggs in that web, gather the web into a ball and carry it around with them. The eggs hatch after 6 to 8 weeks.
With its 30cm long legspan, fearsome fangs and hairy body, it seems difficult to admire the Goliath birdeater. But I hope I have shown you that this arachnid possesses some incredible adaptations and has evolved to become a successful rainforest predator.