Our Latest News

Fly Neighbourly Advice for the Tasman National Park

24/08/2019

Public comment is invited on the draft Tasman National Park Fly Neighbourly Advice. The draft Fly Neighbourly Advice has been prepared by the Tasmania Parks and Wildlife Service in response to increasing air traffic over the Tasman National Park.More

Hybrid diesel-electric shuttle buses at Cradle Mountain - a first for National p

19/08/2019

When you next visit Cradle Mountain you will be able to step aboard one of the new hybrid, diesel-electric, shuttle buses on your trip to Dove Lake. These new buses will reduce emissions and deliver a quieter, all mobility friendly, visitor experience.More

AFAC Independent Operational Review of the 2018-19 bushfires

08/08/2019

Following the 2018-19 bushfires the Tasmanian Government commissioned an independent report by the Australasian Fire and Emergency Service Council to review the overall response and identify areas where more can be done to improve the State's response andMore

Macquarie Island Pest Eradication Project

The Pest Problem



macqaurie island plot
The rabbit exclosure above shows that the vegetation of Macquarie Island
is capable of regenerating with the absence of rabbit grazing in just a few years.
This exclosure contains naturally regenerating Macquarie Island cabbage
.

Rabbits

Rabbits were introduced around 1880 from New Zealand to provide a food source for crews living on the island and harvesting seals and penguins for their oil, and rabbits gradually spread across the whole island. Damage to vegetation from overgrazing by rabbits was noted as severe in the 1950s and continued as rabbit populations fluctuated over subsequent decades. Vegetation recovery was apparent from the late 1970s to the late 1990s as rabbit numbers were brought under control by myxomatosis. Vegetation damage then increased significantly from the late 1990s. European rabbits (Oryctolagus cuniculus) favoured the grasses and large leafy megaherbs, including the tussocks Poa foliosa, P. cooki and P.litorosa, Macquarie Island cabbage Stilbocarpa polaris and the silver-leaf daisy Pleurophyllum hookeri. These species have no adaptations to cope with grazing.
 
Vegetation communities are a critical part of the Macquarie Island ecosystem as they protect soil and rocks from weathering, stabilise steep slopes and provide habitat for invertebrates and burrow-nesting seabirds.

Rabbit grazing changed areas of tall tussock grassland to modified forms of herb-field, thereby affecting the breeding success of burrowing seabirds that require vegetation cover as part of their breeding habitat.

The loss of vegetation contributed to destabilisation and erosion of steep peat-covered slopes, which also impacted on albatross nesting sites. Two landslides in 2006, at least partially caused by rabbit grazing, were responsible for the deaths of penguins and damage to visitor boardwalks on the island.

Rodents

Rodents also had a significant impact on the island, particularly ship rats Rattus rattus, which are omnivorous and will prey on chicks and eggs of burrow-nesting petrels. 

Ship rats and house mice Mus musculus also impeded plant seedling recruitment and foraged on invertebrates. 

Ship rats presented a threat to at least nine bird species that breed on Macquarie Island.

Pests on islands

Wildlife on islands, particularly those on islands such as Macquarie which are isolated in a geographical and evolutionary sense, are extremely vulnerable to introduced species. 

Plants and animals in such places have evolved in isolation and are adapted to unique local conditions; many do not have the ability to resist the invasive characteristics of alien introductions. For example, the tendency of rails to evolve flightless forms on islands has led to the disproportionate number of extinctions in that family as a result of predation by introduced species. The Macquarie Island rail (and Macquarie Island parakeet), for example, are now extinct due to predation by cats and weka. 

Introduced species often have no natural predators or are able to fill a vacant niche. Rabbits were extremely successful on Macquarie Island due to the lack of competitors for food resources. 

Experts working on introduced species agree that islands (and other geographically and evolutionary isolated places) face different threats to biodiversity compared to continental situations. They are more vulnerable to invasions and more likely to suffer catastrophic loss of biodiversity as a result of invasions. Fortunately such places are also more likely to respond well to successful pest eradication campaigns.