On Valentine’s Day ten years ago, intrepid scientists scaled the steep cliffs of Ball’s Pyramid to collect some of the world’s rarest insects.
Two days later, two large insects arrived at Melbourne Zoo. They were among the few survivors of a species that had been believed to be extinct since the 1920s, when rats ran aground from a ship and devoured defenseless native wildlife on Lord Howe Island.
A tiny colony somehow survived on Ball’s Pyramid, the steep sea stack about 20km from the original home of their ancient species.
Inevitably, Zoo staff started calling the pair Adam and Eve, because it was hoped that it would be possible to set up a successful endangered species breeding program so they would become the ancestors of individuals that could return to Lord Howe Island in the future.
There were no scientific sources of information about this species, so keepers had to learn everything through observation. One of the first surprises was that they are nocturnal, unlike other stick insects.
The adults are dark brown to black, providing excellent after-dark camouflage, but the tiny hatchlings are light green and active by day.
Some zoo-bred individuals have already returned to Lord Howe Island, where they are on display for residents and visitors. The long term aim of the breeding program is to reintroduce large numbers once authorities have implemented a rat control program.
Ten years from Adam and Eve’s arrival, the Invertebrate Team has recorded the first hatchings of the 10th generation of their descendants, with more than 10,000 eggs hatching successfully at Melbourne Zoo.
Lord Howe Island Stick Insects are one of the native species included in Zoos Victoria’s Fighting Extinction campaign.
The significance of this breeding program has recently been highlighted by a visit from Sir David Attenborough, who was briefed by keepers on the scope of the project and visited the behind-the-scenes breeding facilities.