How Long Do Tarantulas Live? Why Females Live for Decades

Tarantula lifespans at a glance

Tarantulas (family Theraphosidae) include more than 1,000 species, and lifespans vary between them. The pattern, however, is the same almost everywhere: long-lived females, short-lived males.

These ages are mostly from spiders kept in captivity, where the hatching date is known and there are no predators. In the wild, many tarantulas die young, and good age records for wild adults are scarce.

Why do female tarantulas live so long?

Female tarantulas have several advantages that allow them to live for decades:

• A slow, low-energy life. Tarantulas are sit-and-wait hunters. A female may stay in the same burrow for years and wait at the entrance for prey, using very little energy. Spiders can also survive long periods without food.
• A safe home. The burrow protects her from heat, drought and many predators. She seals it with silk when she is most vulnerable, while molting or guarding eggs.
• Molting as adults. Unlike most spiders, female tarantulas keep molting after they mature, usually about once a year or less. Each molt replaces the exoskeleton, including worn hairs and fangs, and can even regrow lost legs. You can read how this works in how do tarantulas molt?
• Slow growth. Tarantulas take years to mature, and slow growth and long life tend to go together in the animal world.

A female can breed many times during her life, laying an egg sac every year or every few years. Living long lets her produce many hundreds of young over decades, which pays off in an environment where most spiderlings are eaten.

Why do male tarantulas die young?

A male tarantula grows like a female until his last molt, called the ultimate or maturing molt. After it, he has hooked spurs on his front legs and mating organs on his pedipalps (the leg-like feelers at the front), and his life changes completely:

1. He stops molting. Mature males almost never molt again, so their exoskeleton wears out and cannot be renewed. The rare males that try often get stuck and die.
2. He leaves the burrow. He spends his remaining time walking, often long distances, to find females by their scent and silk. In the southwestern United States, wandering males are the tarantulas most often seen crossing roads in late summer and fall.
3. He takes big risks. Walking in the open exposes him to birds, mammals, spider-hunting wasps called tarantula hawks, traffic and bad weather. Females are sometimes aggressive after mating, although eating the male is less common than often claimed.

Evolution favors males that put all their effort into mating soon after maturity rather than into a long life. Most males die within months to about a year after their final molt, at a total age that often lies between about three and ten years, depending on the species.

How long do tarantulas live in the wild?

This is much harder to answer than it sounds. Following one spider in the wild for decades is rarely possible, and spiders cannot be aged from their bodies the way trees can be from their rings.

What is clear is that most tarantulas never reach old age. A female lays hundreds of eggs, and the spiderlings are eaten in huge numbers by ants, birds, lizards, centipedes and other spiders. The few that reach adulthood, especially females in good burrows, can probably live for many years, but reliable wild ages for tarantulas are lacking.

The best evidence for long life in the wild comes from a related group. Tarantulas belong to the mygalomorphs, an ancient branch of spiders that also includes trapdoor spiders. In Western Australia, researchers studied one population of trapdoor spiders from 1974 onward. A female known as “Number 16” lived in the same burrow for decades and died in 2016 at an estimated 43 years old, the oldest spider ever recorded. Her case shows how long a burrowing spider can live when undisturbed.

How tarantulas compare with other spiders

Most familiar spiders, such as orb weavers and wolf spiders, belong to a different group, the araneomorphs. Many of them live only one or two years, and female house spiders often two years or more. Females of most araneomorph spiders stop molting once mature.

Tarantulas and other mygalomorphs are different: heavier, burrow-dwelling, slow-growing and long-lived. For a broader comparison across all spiders, see how long do spiders live?

Myths about tarantula lifespans

“All tarantulas live for 30 years.” Only females of some species reach such ages, and only under good conditions. Males of the same species may live just a few years.

“Male tarantulas are always eaten after mating.” Females can attack males, and males usually leave quickly after mating, but most males die from age, exhaustion or predators while wandering, not inside a female’s burrow.

“A tarantula skin on the ground means a dead tarantula.” Often it is just a shed skin. Tarantulas leave behind a complete hollow copy of themselves each time they molt, a sign that the spider is still alive and growing.