Theraphosa stirmi

Theraphosa stirmi, better known as the Burgundy Goliath Birdeater, hails from the humid rainforests of northern South America, particularly Brazil, Guyana and Suriname. These forests provide rather balmy, muggy conditions—perfect if you’re an eight-legged tank with a fondness for moist soil and dark hides. In the wild, T. stirmi is most at home under dense foliage, rotting logs and leaf litter near water sources. The region is typically warm year-round with high humidity, frequent rain and, unsurprisingly, lots of bugs to snack on. If you want to make one of these giants happy, try recreating a little patch of Amazon under a sturdy lid at home.

The Burgundy Goliath is one of the true heavyweights of the spider world, reaching a whopping 20–23 cm diagonal leg span (occasionally more if yours eats its Weetabix). Females, as usual in the tarantula world, are the bigger, burlier siblings, sporting much heavier bodies and longer lives. Males still get big but tend to be leggier and less robust. In short: whichever sex you end up with, expect a hefty housemate that demands a fair bit of space and respect.

T. stirmi is the poster child for terrestrial tarantulas—a solid ground-dweller that spends most of its time either sitting out in the open like a garden gnome or lurking just inside a burrow. In captivity, you’ll find they often dig shallow scrapes or modify their hides with some light excavation. Not fans of heights, they much prefer their feet firmly planted in deep, damp substrate. While not true fossorials, they’ll appreciate enough substrate to act out the odd half-hearted dig. Give them cover and they might treat you to a regal pose at the front of their enclosure, surveying their kingdom.

Females regularly clock in at around 12–15 years in captivity, sometimes surprising you with a few bonus years. Males, ever the party animals, mature faster and burn out quicker—often managing just 3–6 years before shuffling off their mortal coil, typically not long after their final moult. With good care, females can become grumpy old matriarchs while you work through several generations of aquarium gravel. Not a bad innings for a spider!

Theraphosa stirmi is no slouch when it comes to growing. Slings can double in size with every meal if you’re generous and conditions are warm, making them medium-to-fast growers by tarantula standards. That said, individual pace varies with feeding, temperature and luck. Don’t be shocked if your spiderlet turns into half a dinner plate in what feels like no time at all—or at least a few years with regular meals and good husbandry.

While T. stirmi may look like it’s wearing angry eyebrows, it’s generally more drama queen than savage beast. More bark than bite, really—they’d rather kick hairs and stamp their feet than launch themselves across the enclosure. That said, they can be defensive when cranky or surprised and move surprisingly fast for something so hefty. Not a tarantula you’d call placid, but usually happiest left alone. Observe from behind the glass and you’ll both stay cheerful.

Aim for a toasty 23–27°C in the enclosure, with little dips down to 21°C doing no harm if your British thermostat takes a nap. Stable warmth brings out their best, so if you’re in a chilly spot, a low-wattage heat mat or heat cable on the side (never the bottom!) can help. Always use a thermostat to avoid roasting your spider. Avoid drafts, rapid temperature swings or direct sun—this isn’t a greenhouse cucumber, after all.

Humidity is key for T. stirmi, who fancies 75–85% RH most of the time. Generous, moist substrate is a must—think of it as potting soil with attitude (coco fibre or peat works wonders). A large water dish is non-negotiable and should be cleaned regularly, unless you like seeing it filled with boluses and tarantula footprints. Balance humidity with good airflow to dodge mould or stuffy ‘swamp tank’ scents. Misting isn’t usually needed if the substrate is right; just keep an eye on things.

When it comes to being spotted, T. stirmi is full-on extrovert compared to some recluses. Adult females in particular are often happy to sit out in plain sight—imposing, statuesque and slightly smug. Nighttime is their big moment; you’ll often see them roaming, grooming or waiting for prey after lights out. They can vanish into their hides if disturbed or moulting, but for the most part, if you want a hefty spider you can actually observe, this is a great candidate.

Webbing? T. stirmi isn’t exactly the Charlotte of the spider world. You’ll see some sparse, irregular silk laid around entrances, over favourite spots or to tether stray leaves and décor, but nothing you’d call spectacular. Instead, silk is mainly used for lining hides or prepping moulting mats. If you’re after an interior designer spider, try a species heavy on the decorating side—these giants keep their webs practical, understated and largely unflashy.

When it comes to meals, if it hops or crawls and isn’t holding a fork, T. stirmi will probably try to eat it. For slings, offer pre-killed or very small live crickets, mealworms or roaches twice a week. Juveniles do well on a couple of medium crickets, dubia roaches or a hearty locust once or twice per week. Adults, being both large and lazy, can be fed one or two good-sized prey items every 7–10 days. Overfeeding leads to chunky spiders with less incentive to move, while power-feeding can stress them and dirty the enclosure. Always remove uneaten prey after 24 hours, especially before a moult—you don’t want your spider wrestling with a curious cricket mid-striptease! As always, remember: feeding time is display time—get your smartphone ready.

You’ll need a robust, escape-proof enclosure with a big enough footprint (think 45x45 cm minimum for an adult) and secure ventilation. T. stirmi likes depth, so provide at least 15–20 cm of moisture-retaining substrate (coco fibre or peat) so they can dig and sprawl. Add a substantial hide—half a flowerpot, a big cork bark tube or a custom-built Hobbit hole. Water dish? Go large and shallow—remember, these brutes will wade in or treat it as a loo. Ventilation is crucial: mesh vents high up and low down stop stuffiness and balance that essential humidity. Decorations aren’t required, but a bit of leaf litter keeps things brisk. Avoid sharp objects, as their abdomens are like beanbags—delicate and not suited to obstacle courses.

T. stirmi is best suited to the keeper with a bit of spider time under their belt. Their size, love of high humidity and tendency for dramatic hair-flicking means they’re not the best starter tarantula, but great for those ready to step up. If you’ve run a moderately demanding terrestrial without growing mould or flooding the flat, you’re probably ready to take on ‘the stirm’. Not for complete beginners, but a rewarding species for the intermediate keeper.

T. stirmi is the tarantula world’s answer to a heavyweight boxer—impressive, dramatic and surprisingly visible. They reward careful, observant keepers with years of show-stopping presence and nightly antics. Their size, care for humidity and capacity for mess-making mean they’re challenging, but not unmanageable. If you fancy spider keeping with a bit of spectacle and aren’t fazed by flicky hairs or owning a spider big enough to be mistaken for a small mammal, you’ll find plenty to love. Just remember: no handling, lots of respect, and you’ve got yourself a real centrepiece for your collection. You have not truly lived until you’ve redecorated a room to fit a spider.