Theraphosa stirmi Rudloff&Weinmann, 2010, also known as “Burgundy goliath birdeater”, is a remarkable bird spider due to its size from Guyana. Theraphosa stirmi is a look-alike from the same region as Theraphosa blondi, often wrongly being sold as Theraphosa blondi. Differences between both are hard to spot for the unexperienced eye. Breedings are more successful and therefore Theraphosa stirmi is much cheaper than Theraphosa blondi. Inform yourself about the differences (below). Bird spiders of the Theraphosa-genus are the world’s biggest spiders.
ATTENTION: This caresheet is very different to almost every other caresheet on the web. In our opinion, Theraphosa stirmi is kept far too warm.
I. SPECIFIC INFORMATION
Scientific name: Theraphosa stirmi.
Also known as: Burgundy goliath birdeater.
Previous names: /
Type: Terrestrial bird spider. Opportunistic burrower.
Category: New world tarantula. The urticating setae of Theraphosa stirmi are remarkably effective against mammals.
Urticating setae: Yes, type III (abdomen).
Venom: Probably mild. No valuable scientific research has been done yet.
Body length: ≤ 10cm.
Span width: ≤ 28 cm.
Growth rate: Relatively fast. Spiderlings do have a remarkable size of up to 1,5cm body length.
Life expectancy: Females can become up to 20 years old. Males are given a shorter lifetime from 3-5 years.
Behavior: Nervous. The spider will not hesitate to shed its urticating setae or start stridulating in an impressive threat pose. Urticating setae of Theraphosa stirmi are remarkably effective against mammals, especially in the eyes and/or inhalation. As the spider gets older, she’ll become calmer. During the day they’ll stay in their burrow. When kept properly, even at night you won’t notice Theraphosa stirmi out in the open. Most of the time she’ll stay at the entrance of her burrow.
Accessibility (1/beginner: 10/expert): 7.
II. INFORMATION FOR KEEPERS
>>> First aid
Theraphosa stirmi lives in tropical humid and warm area, in the primary tropical rainforests of South-America. Temperatures almost daily reach levels up to 30°C with very high humidity, but… Because of the fact the area she lives in is very dense, with high trees and lots of vegetation, light and warmth is not passing through properly. Therefore environmental temperatures are a few degrees lower than above the trees. Burrows, with depths up to 1,5m, are often being built on slopes in montaneous area, trying to create a rather cool and humid environment. Please do not make the common mistake, providing wet substrate in an overheated terrarium.
Temperature: 18-22°C (day), 18-20°C (night).
* When kept too dry, Theraphosa stirmi might experience (fatal) problems during molt. Perfect environmental factors are crucial for survival.
* When kept too wet with poor ventilation, fatal fungus might start to grow on the spider’s abdomen. Spray the tank once (sometimes twice) a day.
* Males are often kept a few degrees lower than females (max. 20°C).
Adult: LxWxH: 60x40x40. Min. 4-5x span width in surface.
Smaller than adult: 4x span width in surface.
* To control high humidity levels, you might like to use real plants in the terrarium and add rounded gravel at the bottom, filled up with water. This is important for both welfare and survival of the spider. Spray the tank once (sometimes twice) a day. Note that cages with high humidity levels are very sensitive for mites and other parasites. Please take your precautions.
Adult: 1x span width.
Smaller than adult: Min. 0,75-1x span width.
* The spider is an opportunistic burrower. Do not deprive her this opportunity in your terrarium. A deep burrow is crucial for successful breeding.
* Because of the fact the spider’s abdomen can become very large, every fall can be fatal. Therefore it’s recommended to reduce height and the opportunities to climb. Do not give more than 20 cm of free space between ceiling and substrate.
Please read carefully the introduction underneath “Information for keepers”.
Wet season: April, May, June, July, August, November, December, January.
Dry season: None. Less precipitation in February-March and August-October.
Warmest months: October, November.
Coldest months: None. Temperatures often reach 30°C, and higher.
* You might like to consider an adjustment of these data with your local climate. Do not exceed minima or maxima and, if necessary, organize the year making your bird spider experience different seasons. This is very important form the moment you’d like to start breeding.
• Setae on the patella and below.
• Setae on the bottom side of the femura.
• Chelicerae and fangs are relatively “short”. As a result the carapace is flatter.
• Mature males lack tibial hooks.
• Spiderlings have dark palps.
• No setae on the patella.
• No setae on the bottom side of the femura.
• Chelicerae and fangs are relatively “big”. As a result the carapace is less “flat” than the Theraphosa blondi.
• Mature males lack tibial hooks.
• Spiderlings and juveniles have 4 blonde/pink tarsi.
• Spiderlings have dark palps.
• Much more setae, especially on the bottom side of the legs.
• In general a pink-/reddish hue.
• Mature males possess tibial hooks.
• Spiderlings and juveniles have 8 blonde/pink tarsi.
• Spiderlings have blond-/pink(er) palps.
III. INFORMATION FOR BREEDERS
Pairing a Theraphosa stirmi does not always run smoothly, even though the man serving as diner for the female is rather the exception. Nevertheless the female can react very defensive towards the male’s presence. Don’t put them together without staying close. Most things go wrong because of too high temperatures. The spider will eat the eggsac or the eggsac starts rotting. High humidity, however, very good ventilation and deep substrate (for a large burrow) is crucial for success. Breeding report 1. Breeding report 2. Breeding report 3.
• Only start breeding 4-6 weeks (or later) after the spider molted. If the female molts between pairing and cocoon, the eggs will remain unfertilized.
• Make sure the female is well-fed (not obese) before you introduce the male. The exception makes the rule, but… Fatter females produce smaller posterity.
• Keep temperatures between 16-18°C for 4-5 weeks after mating. Let the cage semi-dry out (but keep spraying once a day, as low humidity is not healthy for Theraphosa stirmi).
• Trigger the lady 4-5 weeks after mating by moistening the substrate, raising up humidity (by spraying, 85%+) and temperature (18-22°C).
• 6-7 weeks after the cocoon was made, 50 spiderlings might show up. Don’t deprive the cocoon, unless necessary.
• Make sure you leave the female in perfect conditions undisturbed after a successful mating.
IV. DID YOU KNOW…
• “stirmi” in the name is referring to Andreas Stirm, a hobby tarantula breeder and donator of holotype and paratype I?
• Theraphosa-species never seem to occur in elevations higher than 1000m?
• When kept too dry, Theraphosa stirmi might experience (fatal) problems during molt? Perfect envioronmental factors are crucial for survival.
• Spiders of the Theraphosa-genus belong to the world’s biggest spiders?
• The diet of a Theraphosa blondi can differ from other bird spiders due to her size? In their natural habitat it’s not uncommon they eat a frog, lizard, bat, rat… Hobbyists sometimes feed them small rodents, such as mices. Don’t exaggerate this, because an unbalanced diet will make your spider obese and unhealthy.
Special thanks goes out to a very confidential and successful breeder of the species who provided lots of the information above!