Land Snails of Lord Howe Island
Australian Museum (AM) scientists Dr Isabel Hyman and Dr Frank Köehler have released the first comprehensive, illustrated field guide to the land snails of Lord Howe Island (LHI).
Featuring over 80 species, with detailed colour photos, the guide showcases how these small unique and beautiful gastropods play a vital role in the health of an ecosystem.
Dr Köehler said that LHI has Australia’s highest diversity of land snails, with around 65 species not found anywhere else.
Lord Howe Island is well-known for its many unique animals, such as the Lord Howe Island Woodhen and the Lord Howe Island Phasmid, Less well-known are the many different species of endemic land snails.” Dr Köehler said.
The field guide reveals the stunning snail biodiversity of LHI, and through the imagery and maps, makes it very easy for both the novice and expert to identify them,” said lead author Dr Isabel Hyman.
Having studied these snails since the AM expedition to LHI and Balls Pyramid in 2017, the authors said that many of the snails have suffered badly from predation by introduced rats since 1918.
“Five species have declined so drastically that they are considered Endangered or Critically Endangered. But following an island-wide rodent eradication program undertaken in 2019, we are hoping to see an increase in the populations of these rare creatures,” Hyman said.
Dr Köehler said that after the rat eradication, they were originally expecting a slow recovery in the snail populations, maybe visible only after two or three years.
However, in March this year, curator of the local LHI museum, Ian Hutton noticed hundreds of the native transparent semislugs on the summit of Mt Gower where previously they would have only seen one or two.
It is even possible that some species we have assumed to be extinct may re-emerge now that the rats are gone,” Dr Köehler said.
Chief Scientist and Director of the Australian Museum Research Institute, Professor Kristofer Helgen said that the field guide should stimulate interest and appreciation of these important species.
Through the field guide, we hope to enhance understanding of the biology and habitats of snails, and increase awareness of the importance of their conservation,” Professor Helgen said.
In November, Dr Hyman and Dr Köehler will return to Lord Howe Island to survey the land snails and document their status after a year rodent-free.
We hope to continue regular surveys to document the recovery and update the conservation status of the many snail species on the island,” Dr Hyman said.
Parmellop Pepicuus on Lord Howe Island. Photo by Ian Hutton
Snails and slugs belong to the phylum Mollusca, which is one of the largest animal groups, second only to the arthropods (insects, spiders, crustaceans, and their relatives.) An important indicator of habitat health, many land snails graze on biofilm – made up of fungi and other micro-organisms in leaf litter or on tree trunks and leaves.
Lord Howe Island is a remote island of stunning beauty in the Tasman Sea, lying between Australia and New Zealand. It is a World Heritage site renowned for its high numbers of endemic plants and animals.
This guide is targeted at both professional and semi-professional malacologists as well as students and amateur natural historians, and will be available at the AM shop upon reopening and online at the Lord Howe Island Museum and at the natural history publisher, Nokomis
Documenting the Land Snails of Lord Howe Island and Norfolk Island was funded by the Australian Biological Resources Study, the Graeme Wood Foundation and the Office of Environment and Heritage.
The Illustrated Field Guide to the Land Snails of Lord Howe Island was funded by a grant from the Australian Museum Foundation