The Tree Lobster: How the World’s Rarest Insect Survived on a Sea Stack

For most of the twentieth century, the Lord Howe Island stick insect was a museum species. There were pinned specimens in drawers, a few old descriptions, and memories from islanders who had once used the big black insects as fishing bait. The living animal had vanished from its island within a few years of a shipwreck in 1918. By the 1930s it was written off as extinct.

Then, on a February night in 2001, two men climbing a crumbling volcanic spire in the Tasman Sea pointed their torches at a single scraggly shrub and found three of them alive. The insects had apparently been hanging on for decades on one of the most inhospitable rocks in the Pacific: Ball’s Pyramid, a sea stack more than 550 metres high with almost no soil, no fresh water and barely any plants.

Since then the “tree lobster” has become one of conservation’s most famous comebacks. Four insects collected in 2003 founded a breeding programme that has hatched more than 14,000 nymphs. The island it came from has been cleared of rats. In early 2026, a survey found insects at two new spots on the pyramid, and island residents are now being asked whether they want the species back. Here is how a creature declared extinct ended up with a second chance, and why the story is not over yet.

An insect the size of a hand, used as bait

Lord Howe Island is a crescent of old volcanic rock about 700 kilometres northeast of Sydney, with two flat-topped mountains, Mount Lidgbird and Mount Gower, at its southern end. It had no human inhabitants until Europeans arrived. Lieutenant Henry Lidgbird Ball of HMS Supply sighted it in 1788 while sailing to the new convict settlement on Norfolk Island. He named the island after Admiral Richard Howe, and on the return trip he noted the sharp pinnacle southeast of it that now carries his own name.

Like many remote islands, Lord Howe evolved its own oddities, and one of them was Dryococelus australis, a large, heavy-bodied stick insect that is the only member of its genus. It looks less like a twig than a small armoured animal. Adults are glossy black or dark brown, wingless, with sturdy legs, and commonly reach 12 centimetres or more. Males have thickened hind legs armed with spines. Settlers gave it the nickname “tree lobster,” and it is easy to see why.

The insects were common enough to be a nuisance. Accounts describe them sheltering by day in hollows of living trees, and they sometimes got into the roofs and walls of houses, where islanders heard them scuttling at night. Fishermen collected them as bait. Nobody, it seems, thought of them as rare.

That changed in a matter of months.

The shipwreck that brought the rats

In June 1918 the steamer Makambo, a cargo and passenger ship of the Burns Philp line, ran aground near Neds Beach on Lord Howe Island. The ship was refloated and repaired after about nine days, but by then black rats had made it ashore. According to the island’s management board, mice had arrived decades earlier, but 1918 was when the rats came, and they were a different kind of predator, and the island’s wildlife had no defence against them.

The damage was fast and permanent. Within a few years the rats had helped wipe out five bird species found nowhere else, including the Lord Howe thrush, the Lord Howe starling, the Lord Howe fantail, the Lord Howe gerygone and the robust white-eye. The island’s management board now links rats to the loss of at least 13 endemic invertebrates and two plants as well. In the 1920s, masked owls were brought in to control the rats. They did not succeed, and became another problem for native birds.

The tree lobster, big, slow-moving and nutritious, was an easy meal. Within about two years the once-thriving colonies had disappeared, according to a history compiled by Prague Zoo, and later searches failed to find any survivors. For decades the species was presumed extinct, a textbook example of what a single introduced predator can do to an island.

A rumour on a rock

About 20 kilometres southeast of Lord Howe stands Ball’s Pyramid, the eroded core of a shield volcano that was active around 6.4 million years ago. Softer rock has worn away, leaving a blade of basalt roughly 1,100 metres long and 300 metres wide that rises straight out of deep water. It is often described as the tallest sea stack in the world. Most of the old volcano lies hidden below the waves.

The first clue that the pyramid might be hiding something came from climbers, not biologists. In 1964, members of a climbing party found a recently dead stick insect on the rock. Climbers reached the summit for the first time in February 1965, and over the following years a few more dead insects turned up. Some scientists thought birds might have carried the remains from somewhere else. Expeditions to find live ones came back empty-handed.

It was hard to imagine an insect surviving there. The pyramid has very little vegetation, no permanent water and constant exposure to wind and salt spray. In 1982 the Lord Howe Island Group, including Ball’s Pyramid, was added to UNESCO’s World Heritage List, and access to the pyramid was tightly restricted. Recreational climbing there is now prohibited.

The night search of 2001

In February 2001, a small team led by scientists David Priddel and Nicholas Carlile landed on Ball’s Pyramid to settle the question. According to Prague Zoo’s account, the trip was partly a response to years of applications from people who wanted to visit the pyramid “for scientific purposes,” usually citing the insect. A proper survey would show whether there was anything there to find.

The team worked their way along a narrow ledge just above the waves and up the lower slopes. During the day they found crickets but no stick insects. On the way back down, they spotted something more promising: large insect droppings under a single shrub of Lord Howe Island tea tree, Melaleuca howeana, growing in a crevice about 100 metres above the sea. That year was exceptionally dry, and it was the only healthy tea tree shrub they found.

The adults are active at night, so the droppings meant a second visit after dark. Carlile went back up with local ranger Dean Hiscox, carrying torches and a camera. Under the shrub and in the leaf litter beneath it, they found living Lord Howe Island stick insects. The first count was three. A follow-up visit in March 2002 found 24, and of the ten whose sex could be checked, eight were female and two were male. That mattered: the 2001 insects had all been female, and since females can lay fertile eggs without mating, it was not clear at first whether any males survived at all.

The discovery was thrilling and alarming at once. The entire known wild population seemed to depend on one shrub on one ledge of one rock. A rockfall, a landslide, a fire or a drought could end it overnight.

Adam and Eve

After two years of permits and planning, a team returned to the pyramid on the night of 12 to 13 February 2003 and collected two breeding pairs. One pair went to Stephen Fellenberg, an experienced private breeder in Sydney who had been on the 2001 expedition. The other went to Melbourne Zoo, where invertebrate specialist Patrick Honan named them Adam and Eve.

The Sydney pair died within about a month, although eight nymphs hatched from the eggs the female had laid. In Melbourne, things nearly went the same way. Not long after Eve began laying eggs, she became seriously ill. Nobody knew much about the species, and there was no textbook to consult. Honan and the zoo’s vets mixed a treatment that, according to accounts from the time, included calcium and melaleuca leaf, and he fed it to her drop by drop through the night. She recovered.

Eve went on to lay about 250 eggs. On 7 September 2003, Australia’s National Threatened Species Day, the first Melbourne nymph hatched. Keepers named it Yarra. It came as a surprise: the nymph was bright green, nothing like the black adults. The zoo later worked out that young nymphs are green and active during the day, while older insects darken, turn nocturnal and hide during daylight, so their colour matches their habits.

The early years were hard. With so few founders, the eggs gradually got smaller and fewer nymphs survived, which the team put down to inbreeding. In 2004 Melbourne swapped four males with the Sydney colony to mix the bloodlines. Even so, the captive population descends from just a handful of wild insects. Melbourne Zoo says its genetic diversity was limited to five wild-caught founders before 2026.

Fourteen thousand nymphs later

Once the husbandry was worked out, the programme took off. Since 2003, Melbourne Zoo has hatched more than 14,000 nymphs. It keeps several hundred adults and nymphs at any time, with thousands of eggs incubating. Each egg takes about six to nine months to hatch, and the colony is now about 19 generations removed from its founders.

Keeping the insects fed was its own puzzle. Melaleuca howeana is endemic to the Lord Howe Island group, and the island’s board allowed it to be grown only to feed the captive insects. Keepers tested dozens of other plants to find foods that could support colonies elsewhere, and to learn what the insects might eat if they were returned to the island’s forests.

Because a single facility is a single point of failure, eggs were sent abroad. Bristol Zoo in England, Toronto Zoo in Canada and San Diego Zoo in the United States set up insurance colonies, and eggs from Bristol later founded a colony at Prague Zoo, which announced in February 2026 that it had hatched 13 nymphs of its own. In 2008, zoo-bred insects went back to Lord Howe Island for the first time, to a secure enclosure where residents and visitors could see the species alive again.

The insects turned out to have some unusual habits for insects. Females lay their eggs while hanging from branches. They can reproduce without males, in which case all the offspring are female, a trick that may help explain how such a tiny population held on. Pairs are also often found resting close together, which has made the species a favourite with zoo visitors.

Was it even the same species?

There was one nagging question. The Ball’s Pyramid insects did not look quite like the old museum specimens from Lord Howe Island. The museum males seemed more robust, with bigger leg spines and slightly different tail parts. If the pyramid population was a separate, closely related species, putting it on Lord Howe might mean introducing something new rather than bringing something back.

In 2017 a team led by evolutionary biologist Alexander Mikheyev answered that with genetics. Writing in Current Biology, they sequenced DNA from captive insects and from museum specimens collected on Lord Howe before the rats arrived. The differences between the two groups were about as small as the variation among the museum insects themselves, so despite the visible differences, the two populations are the same species.

The same year, an Australian Museum expedition worked with rock climbers to survey the pyramid and brought back a new female, nicknamed Vanessa, to add fresh genes to the Melbourne colony. Climbers on an unauthorised ascent in 2014 had reported live insects near the summit, around 500 metres up, living among sedges. The insect, it seemed, was not limited to one bush after all.

Clearing the island of rats

None of this would mean much if the rats were still on Lord Howe. For decades islanders fought them with shooting, dogs, bounties and poison, and they never got close to winning. In 2019, after more than 15 years of research and planning and plenty of local argument, the Lord Howe Island Board carried out a full rodent eradication.

Between May and December 2019, poison bait was spread across the island, much of it dropped from helicopters. To keep native birds from eating the bait, the island’s entire wild population of Lord Howe woodhens, along with endangered Lord Howe currawongs, was rounded up and held in captivity until the baiting ended. The project also set out to remove the introduced masked owls. Ball’s Pyramid, which never had rats, was left alone.

It was not a clean finish. In April 2021 a live male rat and a pregnant female turned up, setting the timeline back. The last recently dead rat was found in August 2021. In July 2023 the board ran an island-wide check with tracking tunnels, chew cards, wax tags, trail cameras and detection dogs, and found no live rodents. The island was declared rodent-free later in 2023. The board describes Lord Howe as the largest permanently inhabited island where rodent eradication has been carried out.

The results have been striking. Woodhen numbers rose from about 200 birds released in 2019 to at least 1,638 by December 2024. Seabirds, land snails and plants that rats used to eat have bounced back too. For the tree lobster, it meant the island it came from was safe again.

New colonies on the pyramid, and a question for the islanders

In early February 2026, on an overnight trip to Ball’s Pyramid, island and state conservation staff controlling weeds found stick insects at two locations. They counted nine and collected seven, two adult males, three adult females and two subadult females, which were taken more than 1,000 kilometres to Melbourne Zoo. Twenty-five years after the rediscovery, the new arrivals more than double the number of wild-caught insects the breeding programme has ever had to work with.

The wild population is still tiny. New South Wales lists it as fewer than 50 mature individuals, and the federal government’s species profile estimates between 9 and 35. The threats have changed too. On the pyramid, the biggest worry now is morning glory, an invasive vine that smothers the melaleuca shrubs the insects depend on. A federally funded project that began in 2024 is clearing the weed, screening captive insects for disease and testing their genetics. Invasive ants and a changing climate are on the watch list as well.

The next step is the most delicate: bringing the insect home. Earlier plans proposed a trial release on Blackburn Island, a small islet in the Lord Howe lagoon that has been replanted with native vegetation for the purpose. In 2026, the Lord Howe Island Board began asking residents what they thought of a return. The chief executive told the ABC that, based on scientific advice, the first releases would most likely be in remote mountain areas of the island’s Permanent Park Preserve.

That consultation is not a formality. The rat poisoning divided the community for years, and the board is asking about risks and concerns as well as opportunities to get involved. As its chief executive put it, the insect “hasn’t been seen here in anyone’s living memory.”

Why the tree lobster matters

Plenty of species have been rediscovered after being declared extinct, but few cases are as clean as this one. The cause of the decline is known almost to the day. The survivors sat on a rock where nobody expected them, protected by the same isolation that made them impossible to find. And every step of the rescue, from Eve’s late-night treatment to the island-wide eradication, can be traced to particular people making particular choices.

It is also a reminder of how close it came. If the 2001 team had not looked under that one shrub, or if a dry year had killed it before anyone climbed up, the tree lobster might have vanished without anyone noticing. As it is, hundreds of them now live in zoos on three continents, a few dozen still cling to a sea stack in the Tasman Sea, and the island they came from is waiting to see if they will come home.

For more on the remote islands that guard their own secrets, see our guide to the Pacific islands you really can’t visit. For another strange clash between Australian wildlife and human plans, read about the Great Emu War of 1932, and for the museum drawers where specimens like the old tree lobsters ended up, see the Bone Wars.

Further reading