Male and female lifespan
Male Theraphosa stirmi are generally expected to live roughly 3–5 years, while females can live 12–18 years. The difference becomes most obvious after maturity.
If you buy a Burgundy Goliath Birdeater as an older juvenile or adult, you may never know its exact age. Use the species range as a guide and keep your own dates from the point you acquire the spider.
Why females live longer
Female Theraphosa stirmi continue moulting after maturity, which allows them to remain healthy adult spiders for many years.
A male Burgundy Goliath Birdeater eventually reaches an ultimate moult. After that point his remaining lifespan is usually much shorter than that of an adult female.
Growth and maturity
Burgundy Goliath Birdeaters are fast growers. Young spiders normally moult more often than large juveniles and adults, but the time taken to mature varies between individuals.
Do not try to estimate the exact age of Theraphosa stirmi from size alone. Feeding, temperature, sex and genetics all influence growth.
Feeding and temperature
A practical temperature range for Theraphosa stirmi is 22–26°C. Stable care and sensible feeding are more useful than trying to force rapid growth.
Keeping a Burgundy Goliath Birdeater very heavily fed does not guarantee a longer life. Fresh water, suitable food, normal moults and stable enclosure conditions matter more.
Mature males
After the ultimate moult, a male Theraphosa stirmi may become more active around the enclosure and may eat less often than before maturity.
That change can be normal for a mature male Burgundy Goliath Birdeater. Keep water available, continue offering food occasionally and make sure the enclosure remains secure.
Keeping records
Record moult dates for Theraphosa stirmi and keep suitable exuviae if you want to confirm sex. If the spider was not bought as a tiny sling, record the date acquired and approximate size instead of guessing an exact age.
Over time, those notes make the lifespan of a Burgundy Goliath Birdeater easier to put into context and help show when growth and feeding patterns change.