Driven To ‘Extinction’ By A Shipwreck, A 2001 Discovery Brought The ‘World’s Rarest Insect’ Back To Life

When the SS Makambo ran aground on the shore of Lord Howe Island in 1918, there was only one immediate casualty—a passenger who drowned as the ship was being evacuated for repairs.

In the decade that followed, the island would say goodbye to five species of birds and 13 species of invertebrates that called it home. The Lord Howe Island stick insect (Dryococelus australis), was among the species that were wiped out rapidly—considered extinct by 1920.

The culprit?

Black rats (Rattus rattus) from the ship who hopped out as the vessel was being repaired on the shore. Their unintended invasion triggered a cascading ecological disaster, with the island’s unique species no match for the industrious rodents.

The Lord Howe Island Stick Insect Was Once So Common, It Was Used As Bait

Known colloquially as the “tree lobster” due to its large size and hard, glossy exoskeleton, this insect was a dominant feature of the island’s nocturnal landscape. Measuring up to 5 inches (12 centimeters) in length and weighing up to 25 grams, it was the largest flightless stick insect in the world.

By day, the stick insect hid in tree hollows, often congregating in significant numbers for shelter, with reports of as many as 60 insects found in a single hollow. At night, they would emerge to feed on the tender leaves of native plants. Their slow, deliberate movements and imposing size made them a familiar, if unusual, part of Lord Howe Island’s ecosystem.

This thriving population came to a catastrophic halt following the Makambo shipwreck in 1918. As black rats escaped the grounded vessel, they encountered an ecological paradise free of natural predators. The Lord Howe Island stick insects, slow-moving and flightless, became easy prey for the opportunistic rats.

Within months, the once-abundant insect population began to plummet, their tree hollow sanctuaries providing little protection against the voracious rodents. By 1920, the species had vanished entirely from the island. Its sudden and complete disappearance marked the loss of a keystone species that had symbolized the island’s unique biodiversity.

And The Stick Insect Wouldn’t Be Seen Again For Decades

After its disappearance from Lord Howe Island, Dryococelus australis was relegated to the pages of history—until whispers of its survival emerged in the 1960s.

Climbers exploring Ball’s Pyramid, a remote, jagged sea stack about 14 miles (23 kilometers) from Lord Howe Island, reported finding freshly dead stick insects. This was perplexing. Ball’s Pyramid, with its sheer cliffs and sparse vegetation, seemed an unlikely haven for life.

These rumors remained unconfirmed until 2001, when David Priddel and Nicholas Carlile, who worked at the NSW Government’s Office of Environment and Heritage embarked on a bold expedition. They wanted to prove that the Lord Howe Island stick insect was indeed extinct.

“We’d get requests from people saying they were going to find this stick insect,” says Carlile, “but then you’d look at the list of people and there wouldn’t be an entomologist on there! At some point Dave just turned to me and said ‘you know, the only way we’re going to put a stop to this is if we go out there and prove the animal is not there.’”

Their team braved the treacherous climb up the sea stack and found themselves in an otherworldly landscape—bleak, windswept and seemingly devoid of life.

But nestled among a cluster of tea tree bushes (Melaleuca howeana) growing in a narrow crevice, they discovered a miracle—three live Lord Howe Island stick insects. The population was precarious, with a total of 24 individuals surviving on this tiny outcrop. Against all odds, the insects had clung to life, their survival dependent on a single bush providing food and shelter.

The question of how the insects reached Ball’s Pyramid remains unanswered. But re-sequencing genomes from older specimens that lived before the shipwreck has confirmed that the insects living on Ball’s Pyramid survived extinction on Lord Howe Island, according to an October 2017 study published in Current Biology.

The insects’ resilience is equally remarkable, possibly bolstered by a unique trait—parthenogenesis. This ability allows females to reproduce without males, a genetic lifeline for species teetering on the brink of extinction.

​​The Lord Howe Island stick insects’ survival on Ball’s Pyramid also benefited from the absence of predators like rats, and the harsh, isolated environment shielded them from human disturbances. However, the precariousness of their existence was clear. Environmental threats, including drought, storms and invasive plants, loomed large over their fragile habitat.

Now, The Lord Howe Island Stick Insects Are Close To Making A Complete Comeback

The rediscovery of the Lord Howe Island stick insect sparked global interest and immediate conservation efforts. In 2003, two individuals—affectionately named Adam and Eve—were transported to Melbourne Zoo. Initial attempts at breeding were fraught with challenges, but persistence paid off.

Today, thousands of Lord Howe Island stick insects have been successfully bred in captivity, with individuals housed not only in Melbourne but also in facilities across the world, including the San Diego Zoo and the Bristol Zoo. Each new generation of these tree lobsters is a testament to its resilience and the dedication of the conservation teams working to ensure its survival.

In 2019, the Lord Howe Island Rodent Eradication Project—a comprehensive and controversial initiative—was implemented. The program involved aerial and ground distribution of rodenticides to eliminate the invasive populations entirely.

The effort faced resistance from some local residents, concerned about the potential environmental impacts of the baiting program, but the conservation team persisted, emphasizing the need of eradicating the rodents to restore the island’s biodiversity.

The program proved successful, with Lord Howe Island declared rat- and mouse-free by late 2019. This milestone paved the way for the reintroduction of the Lord Howe Island stick insect to its ancestral home.

Plans are now underway to carefully reintroduce the species, ensuring that their delicate population is given every chance to thrive in a habitat free from the invasive predators that nearly drove them to extinction.

The Lord Howe Island stick insect’s comeback highlights nature’s ability to survive against all odds. Do stories like those of this stick insect inspire you to learn more about the world around you? Take a quick science-backed test to see where you stand on the Connectedness to Nature Scale.