Male vs Female Tarantula Lifespan: Maturity & Sexing Calculator

Sex decides a tarantula's future more than anything else. This page sets the two life stories side by side, explains why males die soon after they mature, and shows how to sex your own spider from its body or a cast-off skin.

Male tarantula lifespan

The male tarantula lifespan is short and ends on a schedule. A male grows like a female for years, then makes a final "maturing" moult and becomes a mature male, built for one job: finding a mate. In a laboratory colony of curly hair tarantulas, males reached that moult after about 4.9 years (1,792 days on average), lived about 1.2 years (437 days) as mature males, and died at about 6.1 years in total (Criscuolo et al. 2010).

Zoos report the same shape for other species. Smithsonian's National Zoo says male Chilean roses die within a few months of mating; Zoo New England says they often don't live past 2–3 years; the University of Kentucky gives rose hair and red-knee males 4–5 years at most. Beardsley Zoo gives Brazilian black males about 6–8 years in total. Totals vary by species mainly because some grow up faster than others; the short life after maturity is the constant.

How long do male tarantulas live after maturing?

Usually one to two years. Criscuolo and colleagues summarise the large Theraphosinae group — which includes most popular ground species — as males maturing at 4–8 years and then living only one or two years after their last moult. Their own curly hair males averaged 437 ± 105 days. In the wild it can be far shorter: Animal Diversity Web says male desert tarantulas live about 2–3 months after their final moult. Exceptions exist — one captive male Chilean rose lived about three years as an adult, which its authors called outside the typical range (Cortés-Fossati & Martín-Rodríguez 2022).

The pink toe figures come from a study summarised by Wikipedia; the green bottle blue figures come from pet-care guides only; no published lifespan exists for the Brazilian jewel, so its row repeats the pink toe as the closest sourced relative. See each species page for details.

Female tarantula lifespan

The female tarantula lifespan is one of the longest of any pet invertebrate. The curly hair females in the same lab colony took about 5.6 years to mature, then lived another 15.9 years as adults, for a total of about 21.4 years (Criscuolo et al. 2010). Smithsonian's National Zoo says female Chilean roses live up to 20 years in human care, and Animal Diversity Web gives female Mexican red-knees 25–30 years.

Unlike males, females keep moulting after they mature. Each moult lets them grow a little, renews worn hairs, and sheds the lining of the sperm stores — which is why a female must mate again after moulting before she can lay fertile eggs (Smithsonian). A female can breed for many years: National Wildlife magazine describes wild female Oklahoma brown tarantulas living around 30 years and breeding for two decades.

• Typical pet range: about 15–20 years or more for common ground species (Zoo New England; Smithsonian; University of Kentucky).
• Shorter-lived exceptions: tree-dwelling pink toes at about 6–9 years (Wikipedia, citing Stradling), and green bottle blues at about 12–14 years according to pet-care guides.
• Why buy a female: the University of Kentucky notes that adult females usually cost more but are a good investment, because they can live for decades.

Why male tarantulas die after maturing

So why do male tarantulas die young? Researchers point to a trade-off between reproduction and body upkeep. Mature males switch from sitting in a burrow to walking long distances, and their resting metabolism rises. In captive curly hair tarantulas, mature males produced more damaging oxygen radicals (reactive oxygen species) in their blood cells the longer it had been since their maturing moult, and their antioxidant defences were weaker; adult females showed no such rise with age (Criscuolo et al. 2010). The authors suggest this oxidative stress is part of why male life collapses after maturity.

Behaviour adds risk on top. A mature male stops moulting, so he can't repair damage or replace hairs. He leaves the safety of a burrow and, in the wild, faces predators, heat, dehydration and cold (Criscuolo et al. 2010; National Wildlife magazine). He eats and drinks less while he searches. Whether in a home or the wild, the male has finished growing and spends what is left on reproduction — biologists call this the "disposable soma" pattern, which Criscuolo and colleagues name as a likely explanation.

Mature male tarantula signs

The mature male tarantula signs appear all at once, at the maturing moult:

• Tibial hooks (apophyses) under the first pair of legs. Smithsonian's National Zoo describes these as a "finger" that hooks and locks the female's fangs while the pair mate. Animal Diversity Web calls them spurs on the front legs.
• Palpal bulbs: the tips of the pedipalps (the short leg-like feelers at the front) become swollen, shiny copulatory organs. Animal Diversity Web describes them as syringe-shaped.
• Longer legs and a smaller body. Smithsonian gives male Chilean roses a 3.5 in leg span against 5 in for females, with proportionally longer legs.
• New behaviour: restlessness, pacing and spinning a small "sperm web".

Not every species has hooks. The small Brazilian tree-trapdoor genus Typhochlaena has no tibial spurs (Bertani 2012), so palpal bulbs are the universal sign.

How to tell a male from a female tarantula

There are three practical ways to answer how to tell if a tarantula is male or female, and the checklist in the calculator uses all three. The drawing shows where to look.

Tarantula sexing by molt

Tarantula sexing by molt works because a female's sperm stores (spermathecae) have a lining that is shed with every moult (Smithsonian). Keepers soften a fresh moult in warm water, unfold the abdomen skin and look on the underside between the first pair of book lungs. A female's moult shows a flap with two small pouches behind it; a male's has no pouches. The shape of the spermathecae differs between species — taxonomists use it to tell females apart (Bertani 2012) — and they are tiny in small spiders, so a magnifier helps.

Keepers widely call moult sexing the most reliable home method (keeper anecdote, Arachnoboards; British Tarantula Society forum). It also has a big advantage over looking at the live spider: it can be done long before a male matures, and it doesn't involve handling.

Ventral sexing and its limits

Some keepers try to sex the live spider from below, comparing the shape of the groove between the front book lungs. Keepers themselves describe this as an educated guess that is often wrong (keeper anecdote, Arachnoboards), so the calculator does not use it. If you only have a live, immature spider and no moult, the honest answer is "not yet known".

Tarantula mating season in the wild

The wild tarantula mating season is when people see tarantulas most: Animal Diversity Web says male desert tarantulas of the US Southwest can be seen from June to December, searching between twilight and sunrise, and the National Wildlife Federation notes that most people only meet tarantulas when males wander in search of females. In south-eastern Colorado, the town of La Junta holds a festival for the males of the Oklahoma brown tarantula (Aphonopelma hentzi), which mature at 5–10 years and walk up to a mile or more (National Wildlife magazine).

A male finds a burrow, drums on its silk lining with his pedipalps and waits for the female to come out. If she is receptive they mate; he uses his tibial hooks to hold her fangs (Smithsonian). Afterwards he leaves quickly. Most wandering males die within months, killed by predators, cars, cold or the female (National Wildlife magazine).

Do female tarantulas eat males?

Sometimes. Animal Diversity Web says some female Mexican red-knees may try to kill and eat the male, although this has not been observed in the wild, and males generally flee after mating; Wikipedia notes that unreceptive female curly hairs may try to kill and eat an approaching male. The National Wildlife Federation adds that a male who lingers may be eaten. Even a male that escapes unharmed has only months to a year or two left (Criscuolo et al. 2010).

How this tool works

Male maturity timeline. Pick a species and enter his age, the date of his maturing moult, or both. With an age, the tool shows the share of a typical male lifespan used and the life stage — the same figures the main tarantula lifespan calculator and the species pages show — and, where a maturity age is published, how far he is from it. Only the curly hair has a published male maturity age (4.8–5 years, Criscuolo et al. 2010); for "Other or not sure" the tool uses the Theraphosinae range of 4–8 years, and for the other species it says no figure is published rather than inventing one. For example, a 4-year-old curly hair male is before his maturity window, with about 0.8–1 years to go.

With a moult date, the tool adds the post-maturity range to that date — 0.9–1.5 years for the curly hair from the lab study, and 1–2 years for other species (Criscuolo et al. 2010) — to give an estimated end window, and says how much of it may be left.

Male or female checklist. Tick what you've seen. Spermathecae in a moult mean female; tibial hooks or palpal bulbs mean a mature male; a carefully checked moult with no spermathecae means probably male. If the signs contradict each other, the tool says so and suggests checking again. Nothing here replaces a look by an experienced keeper or an exotic vet.

Frequently asked questions

General information only — no medication advice. For a stuck moult or injury, see an exotic vet who treats invertebrates.