In the arid heart of Western Australia, a record was quietly broken that few could have anticipated. Not a human, but a spider, etched her name into natural history: “Number 16,” an unassuming trapdoor spider of the species Gaius villosus, lived for an extraordinary 43 years – a lifespan exceeding that of many musical legends. Her remarkable longevity captivated generations of researchers and reshaped understanding of aging in the animal kingdom.
The research surrounding Number 16 began in the mid-1970s, when Australian arachnologist Barbara York Main began observing a small colony of these ground-dwelling spiders. One spider, later designated “Number 16,” outlived all the others. She spent her entire life within the same burrow in the North Bungulla Reserve in Western Australia. Her death in 2016, officially recognized her as the oldest known spider in the world – and the result of one of the longest animal studies ever undertaken.
Oldest Spider in the World: A Record from Australia
The study of Number 16 commenced in 1974, when her burrow was first marked. For decades, Main returned to the same location to document the survival of her subjects. The researcher maintained a rigorous discipline – even birthday treats were forbidden to avoid influencing the study. This painstaking approach yielded one of the rare examples of true lifetime research within a natural spider habitat.
Number 16 is believed to have died from a sting inflicted by a parasitic wasp, whose larvae typically feed on the body of their host. The discovery of her damaged burrow in October 2016 confirmed her death. In 2018, Leanda Mason and Barbara York Main published their findings in the journal Pacific Conservation Biology, confirming the spider had reached the age of 43, significantly surpassing the previous record holder, a 28-year-old tarantula.
While most spiders live only a few years, some Australian species achieve remarkable ages due to their sedentary lifestyles. Female trapdoor spiders never leave their burrows, conserving energy and avoiding many predators. Experts theorize that this strategy – stillness over risk – was crucial to Number 16’s exceptional longevity. Similar adaptations are observed in cave spiders of Tasmania.
The story of Number 16 demonstrates how much even small creatures can teach us about lifespan, adaptation, and site fidelity. Long-term projects like this provide rare insights into natural aging processes – a topic gaining new significance in an era of rapid species extinction. Researchers hope to draw lessons from such studies for conservation efforts and ecosystem resilience – and to further unravel the secrets of spider longevity.
Number 16’s life began in 1972 or 1973, according to researchers, shortly after Barbara York Main initiated her long-term study of spider families. Main marked ten spiders, returning the following year to find new spiderlings, including Number 16, likely born after the first autumn rains of 1974. As Number 16 aged, researchers developed a tradition of checking her burrow first during their annual visits.
The dedication to the project extended for decades, with Main continuing her work well into her 80s. When Main’s health eventually declined, she passed the project on to Leanda Mason, ensuring the continued monitoring of Number 16 and the other trapdoor spiders. The longevity of Number 16, and the commitment of the researchers involved, highlights the value of long-term ecological studies in understanding the natural world.
