The last conservation spotlight we had (Save the Vaquita) showed the rapid decline of a species about to become extinct. This month, we are highlighting a species that was thought to be extinct, only to be rediscovered in the most unlikely of places. 

This is the story of the Lord Howe Stick Insect's extinction, and of its future.

Lord Howe Island. Image courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center.

​Lord Howe Island is an irregular crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand. This island's biodiversity has been recognised, and the island group it belongs to has been designated a World heritage Site by UNESCO. Most of the island is covered in untouched forests, hosting a large number of endemic animals and plants.

​One of these animals was the Lord Howe Island Stick Insect (Dryococelus australis), otherwise known as the 'land lobster', These large, flightless, nocturnal insects can measure up to 12 cm, and can weigh up to 8-9 grams. During the 19th century there were so many of them that fishermen would commonly use them as bait!

​However, mice were introduced to the island by accident, and this was followed by the introduction of back rats in 1918. With these mammals making a meal of the insects, by 1920 not a single individual was recorded on the island, and by 1960 they were officially declared extinct.

Ball's Pyramid is the last refuge of the Lord Howe Island Stick Insect. dracophylla/Flickr

​For decades, this insect was thought to be lost to the history books as yet another victim of invasive alien species. However, this is where Ball's Pyramid comes in. This volcanic rocky outcrop found 23 km off the coast of Lord Howe Island is said to be the tallest volcanic stack in the world.

​It is so narrow that there is no way anyone can land a boat on it. Instead, scientists have to jump from the boat onto the Pyramid, hoping the seas stay calm enough for the boat to retrieve them the following day. In 2001, a group of scientists undertook an expedition to Ball's Pyramid to see whether any of the supposedly extinct insects could have managed to survive on the island. 
​

A breeding colony of Lord Howe Island Stick Insects was founded at Melbourne Zoo. AAP

A magical thing happened on that trip. On a nocturnal climb up to the sparse vegetation of Ball's Pyramid, a scientist's headlight was caught on a reflective surface. That surface turned out to be the exoskeleton of a Lord Howe Stick Insect.

These insects were found on a Melaleuca howeana bush growing out of a small crevice, supported by a small build-up of soil. This small plant supported the entire population of the species, which was estimated to be between 24 and 40 individuals.

​The Lord Howe Stick Insect soon gained the reputation of being the rarest insect on Earth. No one is entirely sure how the population made it from Lord Howe Island to the relative safety of Ball's Pyramid. The insects might have been carried over with nesting material by the common noddy birds that nest on the island. Despite this incredible discovery and the knowledge that the species was still alive, it took another three years to get permission to collect them for captive breeding. 

Ball's Pyramid, a massive ocean stack about 20 km off the coast of Lord Howe Island. (Supplied: Tom Bannigan, Australian Museum)

​In 2003, a rescue team leapt ashore with the aim of collecting the animals and bringing them back to mainland Australia. At this time, other than knowing it lived on the Melaleuca plant, there was very little else known about the species.

​Melbourne Zoo played an integral role in saving this species. With only two breeding pairs of animals being brought to the mainland, one pair was sent to the Zoo, and another to a private breeder in Sydney. The health of these animals was crucial for the continuation of the species. ​

The original pair held at Melbourne zoo were named Adam and Eve. At one point, Eve nearly died, but she was thankfully revived by zookeeper Patrick Rohan, who carefully dropped a mixture of sugar, calcium and ground melaleuca leaves into her mouth. It was in large part his dedication to Eve during these long nights that allowed the species to survive.

Eve’s first egg hatched on Threatened Species Day 2003, and although this was not the end of the challenges facing Melbourne Zoo staff, it turned out to be the beginning of the species’ successful captive breeding program.

Lord Howe Island Stick Insect at Melbourne Zoo. Credit: Rohan Cleave, courtesy of the Eureka Awards

​By 2006, the population had grown to a respectable 50 individuals, with thousands of eggs still to hatch. In 2008, the population had grown to 700 individuals and 11,376 eggs. Twenty individuals were selected to be returned to a special habitat created on Lord Howe Island. 

​The long-term plan is for rodents to be eradicated from Lord Howe Island and for the captive population of stick insects to be reintroduced. A species of owl is also expected to be reintroduced in order to keep the new population in check.

Lord Howe Island Stick Insect enclosure on the forest edge of Lord Howe Island. Credit: Nicholas Carlile

​To protect these animals, individuals were sent out to other zoological parks, with eggs sent to San Diego, Toronto and Bristol. These new colonies will join those at the Melbourne Zoo and the Lord Howe Island Museum to ensure the future of this unique species.

Sticky from jilli rose on Vimeo.