The most striking feature of Macquarie Island is
the abundance of seabirds - Skuas, Shearwaters, Petrels, Prions,
Albatross and of course, penguins - and the mammal fauna, all of
which contribute to the nutrients in the soil. As the island has never
been connected to an adjacent land mass, all flora and fauna has arrived
there via long-distance oceanic dispersal. The flora shows taxonomic
linkage to other subantarctic islands, the continents to the west
and the islands to the south of New Zealand. Those plants which have
managed to reach and successfully colonise the island exhibit a range
of strategies for dissemination, reproduction and colonisation. The
flora is rarely over 1 m. tall and although not particularly diverse has
45 vascular plant species and 91 species of moss as well as a rich population
of liverwort and lichen. The flora is classified as growing in 5 main
vegetation formations - grassland, herbfield, fen, bog and feldmark. Three
plants - Azorella macquariensis, Puccinellia
macquariensis and Corybas dienemus are endemic.
Research continues to increase the number of species discovered and
reclassified. In 1981 Macquarie Island became a restricted area and
collection of scientific specimens requires a permit.
UPDATE 15 July, 2006
Since this item was first presented in 1999/2000 major changes
have occurred to the island vegetation. Tasmanian University scientists,
Justin Shaw and Jenny Scott, have written a paper showing the devastation
by rabbits during the past six years when the last of the feral cats
was eradicated. This element, plus the fact that rabbits have developed
a natural resistance to myxomatosis, together with a climate change bringing
warmer and drier winters, has enabled rabbits to breed successsfully all
year round. Until recently, winter breeding was unsuccessful because the
kittens would drown or females were too thin to breed.
Pest Eradication Update December
Following the announcement that the Tasmanian and Australian
Government would jointly fund the $24.6 million project, Tasmanian Parks
& Wildlife Service have announced details of a seven-year project
to rid the island of rabbits and rodents. The plan will involve helicopters
dropping pellet baits targeting rabbits, rats and mice.
Work now under way includes construction of sixteen 5x5 metre
plots protected by rabbit-proof fencing in a bid to protect specific
locations of plant species that are under severe pressure. These will
complement other existing scientific exclosure plots and prevent reintroduction
as rabbits are removed.
Other actions include over-flight trials of helicopters and
test baiting around penguin colonies to determine the response of the
penguins to these activities. Discussions have also been held
with skilled dog trainers. Dogs will have a crucial role in the success
of the project, following up the major baiting phase with on-ground
hunting of surviving rabbits. The dogs will assist hunters and must be
trained to focus on rabbits while avoiding non-target species, in particular
native animals More information about the eradication program can
be found on Parks and Wildlife Service website www.parks.tas.gov.au
Update November, 2009
In December 2008, a botanist from the Australian Antarctic Division
first noticed that more than 90 per cent of this endemic cushion plant
had died or is dying. There are a number of possible reasons for this
die-back, the first being that the mean temperature has increased by
more than half a degree over the past 50 years and the island is drying
out and warming up. It is not so much a case of less rain than a change
in rain and wind patterns. This situation is affecting other sub-polar
islands around the world.
Secondly there is the over-population of rabbits (since the eradication
of feral cats - see above), which are causing a lot of physical damage.
Warmer temperatures has enabled the rabbit kittens to survive.
This problem should be ameliorated when the hunters and their specially
trained dogs set their sights on the island in May 2010.
Thirdly a pathogen may be responsible for the plant's plight.
It is now considered to be critically endangered and the Antarctic
Division has joined forces with the Royal Tasmanian Botanical Gardens
in Hobart, the DPIPWE (Dept of Primary Industries, Parks, Water
and Environment), Parks and Wildlife, UTAS (University of Tasmania)
and New Town Laboratory to try to save this cushion plant population.
Dr Jenni Whinan, senior ecologist of DPIPWE fears any increase
in the die-back will bring a new set of environmental concerns including
soil erosion, to the island.
Seeds of Azorella macquariensis have been collected
for the Millenium Seed Bank and plant material has been set aside for
tissue culture testing. Twenty healthy plants, currently in quarantine,
are also to be located at the botanical gardens in Hobart. Work is under
way to try and mimic the sub-polar conditions the species needs to survive
while in captivity."It is proving very difficult to give the plant the
same conditions here", Dr Whinan said. "The lights have been changed in
the quarantine area where the plants are housed, along with temperature,
and fans are used to try and keep the plants, which normally grow in very
exposed conditions, as healthy as we can."
Tight biosecurity measures are in place to ensure any pathogen
does not leave the island and cause environmental problems in mainland
2014 UPDATE: Macquarie Island faces new battle against mysterious azorella
Pest Eradication Update 18 April 2010
In an effort to restore environmental damage caused by the excessive
rabbit population, special baiting is about to commence. This will be
followed in August by the use of hunting dogs which have been especially
trained to be “prey specific”, to protect the general wildlife.
Seed from some of the heavily damaged plant species have been collected
and brought back to the Royal Hobart Botanical Gardens, for germination
and ultimately used to repair the depleted areas.
Pest Eradication Update #2 27 August 2010
The pest eradication programme, planned for August,
when highland areas were to be baited, with follow-up hunting, had to
be abandoned due to extremely bad weather. Some baits, already laid,
had the unfortunate effect of poisoning some seabirds. The programme
will be resumed in April 2011.
Pest Eradication Update #3 20 April 2011 (Adapted
from a report by Felicity Ogilvie)
Another attempt is underway to try to kill every rabbit, rat and
mouse on the island. In 2010 the program had to be stopped because of
bad weather, but the staff are heading to the island a lot earlier this
year. There was also some collateral damage last year when native
sea birds were killed by the bait. Steps have been taken to prevent that
from happening again. After an extensive review process extra staff
are being taken on site to collect the carcasses. There is
one big difference this year - calicivirus has been released this summer
which has been enormously successful and has taken out at least 50% of
the rabbit population already. It’s too early to know if the baiting
has made any difference to the destruction of the vegetation and the land
slips, but early
signs suggest that vegetation could recover extemely quickly once
by animals ceases.
Pest Eradication Update #4 26 April 2012. (Adapted
from a report by Fiona Breen)
Greenery returns to rabbit-ravaged hills
The arrival of hunting dogs and their handlers, added to
the affects of the calicivirus was almost the final straw in the decimation
of the rabbits. The island is already showing a rapid regrowth of
plants, especially the endemic cabbage and the tall tussock grass and there
is a return of seabirds which are breeding more successfully since
the predatory rats have gone. Now that poisons are not used to kill
the rabbits, the sad loss of seabirds (who died after eating the carcasses)
has not recurred.
A new team of six dog handlers, 10 dogs and another group of hunters
will keep up the search. Another group of hunters will follow this one
in 2014 until every rabbit is caught.
For the many who work and visit this magnificent island there's a real
hope that the eradication team will succceed and the island will return
to the flora and fauna sanctuary of the past.
Pest Eradication Update #5 7 April 2014.
MACQUARIE ISLAND - MISSION ACCOMPLISHED!
On 7 April, 2014 one of the world’s biggest island pest-eradication
when a team of hunters and dog-handlers returned to Hobart after spending
months walking 90,000km across the 12,785ha island to make sure the
last of the
rodents and rabbits had finally gone. Significant signs of recovery
in terms of
vegetation were showing and some species such as the blue petrel were
after years of being too nervous to nest there.
References and acknowledgements
1. Flora of Australia Volume 50, Oceanic
Islands 2 . Australian Government
2. Subantarctic Macquarie Island.
P M Selkirk, R D Seppelt and D R Selkirk,
3. J. R. Croft and M. M. Richardson
- Australian National Botanic Gardens, Canberra
The Australian Plants Society would like to thank
the Royal Tasmanian Botanical Gardens for their kind co-operation
in the preparation of this item.
Special thanks to M. Fountain and M. Brown of
the Royal Tasmanian Botanical Gardens, Hobart