Return of the Lord Howe Island phasmid to Lord Howe Island, Australia

Summary

The Lord Howe Island phasmid (Dryococelus australis), a giant nocturnal stick-insect presumed extinct for over 70 years after ship rats reached its namesake island in 1918, was rediscovered in 2001 as a single population of about 20 individuals on the isolated rock stack Balls Pyramid, prompting Australia's NSW Department of Environment to establish captive breeding as a precursor to reintroduction. Two founding pairs removed in 2003 struggled initially, one pair dying within a month and survivors at Melbourne Zoo producing poor hatch rates until husbandry improved by the third generation; the population then grew rapidly, reaching over 700 individuals and 14,000 eggs by 2009 and supporting additional colonies elsewhere, plus a display colony on Lord Howe Island itself. Actual reintroduction cannot proceed until introduced ship rats and house mice are eradicated from the island, complicated by a resident population of about 350 people; a feasibility study, cost-benefit analysis and peer-reviewed operational plan for eradication have been completed, alongside plans to eradicate the introduced masked owl, which could switch to preying on native birds once rodents are gone, and eventually reintroduce the locally extinct boobook owl as a natural phasmid predator. Major difficulties included conducting captive breeding with no prior ecological knowledge, given the inaccessibility of the wild population, and coordinating with the eradication of three separate introduced species. The project rates itself Partially Successful, having secured the captive population but with rodent eradication, owl management and the actual wild reintroduction still pending.