Larger animals tend to live longer than smaller ones-this is a well-established pattern in the animal kingdom. Ants, for instance, have an average lifespan of a year or two while blue whales can live up to 100 years under optimal conditions.
There are, however, exceptions to this rule. One particularly noteworthy exception was documented in the North Bungulla Reserve in southwestern Australia, where a trapdoor spider-a common arachnid in this region-lived to the incredible age of 43.
We know this thanks to the work of Australian arachnologist Barbara York Main. In 1974, Main began a long-term study of trapdoor spider families and how they survive in the menacing bushland of southwestern Australia. Trapdoor spiders, as their name suggests, are burrowing spiders. They erect multiple "trapdoor" entrances to their burrows and cover them with a silk-weave in an effort to ambush small insect prey.
Main identified 10 spiders to track in 1974. One of those spiders soon produced spiderlings, of which "Number 16" was a part of. Main went back each year to check on the status of the spiders, including Number 16.
As decades passed, many of the original spiders died, but Number 16 survived. She was a female spider (females tend to outlive males in the spider kingdom) and she stayed in her same burrow for her entire life. As time went on, Main and her research team made it a habit to always check Number 16's burrow first.
On her 29th birthday, Number 16 became the longest living spider known to science -- beating out the previous record holder, a Mexican tarantula, who died at the age of 28.
Number 16 survived until 2016. Her death was likely due to a parasitic wasp-as Main's team noticed that her burrow cover had been pierced. These wasps implant eggs inside other insects and, when they hatch, they feed on the host.
Number 16's longevity speaks to the incredible adaptations of trapdoor spiders and their ability to thrive in unforgiving environments. Among the reasons why trapdoor spiders are ultra survivors are:
Trapdoor spiders are a type of burrowing spider known for their unique behavior and distinctive physical traits. Typically ranging from 1 to 3 inches in size, they have sturdy, stocky bodies covered in dense, dark-colored hairs, often brown or gray, which help them blend into their environment. Their powerful legs allow them to dig and maintain deep burrows, which they line with silk to create a hidden and secure retreat. One of the most notable features of trapdoor spiders is the "trapdoor" they construct to cover the entrance of their burrow. Made from soil, plant material, and silk, this hinged door enables them to quickly ambush passing prey, such as insects, when they detect vibrations near their burrow.
Trapdoor spiders are nocturnal and solitary hunters, emerging at night to hunt using vibration rather than vision to detect nearby prey.
Trapdoor spiders are closely related to tarantulas, as both belong to the Avicularioidea superfamily of spiders. While tarantulas are more active hunters, trapdoor spiders have evolved to rely on their burrows and ambush techniques for survival. Despite their differences in hunting behavior, both share similar anatomical features, such as large, powerful bodies and formidable chelicerae used for capturing prey.