Conservation of Island Invertebrates

Land snails living on island archipelagos exhibit high diversity and endemism, but have suffered more extinctions than any other group worldwide, primarily due to habitat destruction and the introduction of exotic predators such as rats. Australia’s highest land snail diversity is found on Lord Howe Island, where there are over 60 recorded endemic species. When rats reached the island in 1918, there was an immediate decline in the largest (and therefore preferentially selected) land snail species, particularly those found on the southern mountains. Several species are thought to be extinct, and four are listed as Critically Endangered, including our target species Pseudocharopa ledgbirdi.

Pseudocharopa ledgbirdi is a small, rock-dwelling terrestrial snail endemic to the southern mountains of Lord Howe Island, where it was once found from the lower slopes to both mountain summits. It has declined dramatically in abundance since 1981, and its range has contracted significantly. We aim to provide baseline data on distribution and conservation genetics of this species to inform better conservation management. We will survey all known populations and search for new populations, using historical records and modelling to predict areas of suitable habitat. We will use non-lethal DNA-sampling techniques and undertake population genetics analysis to assess population health and connectivity to improve conservation outcomes.