islandNet Newsletter 6, Feb 2011

Newsletter #6, February 2011
Contents
ISLANDS IN FOCUS: AUSTRALIA .......................................................................................................... 2
Macquarie Island update – next phase planned for April ............................................................................ 2
Rats...Pipes...Cameras...Action! A vertical bait station and remote camera trial
on Muttonbird Island, New South Wales ................................................................................................. 3
Foxes in Tasmania — an update ............................................................................................................... 4
ISLANDS IN FOCUS: INTERNATIONAL .................................................................................................. 5
‘Project Restore’ Taranga (Hen) Island kiore eradication ...................................................................... 5
Rat Island officially declared rat free .......................................................................................................... 6
Confirming success of aerial rat eradications on Mexican islands .............................................................. 6
Attempting eradication of Norway rats on Fregate Island, Seychelles ........................................................ 8
IA CRC workshop on rabbit eradications on islands................................................................................... 8
Progress on South Georgia Habitat Restoration Project............................................................................. 9
Rehabilitating the Seychelles ..................................................................................................................... 9
FEATURE ARTICLE: Appreciating eradications from a tourist’s perspective
— a visit to Antarctic islands ...................................................................................................................... 9
RECENT NEWS & PUBLICATIONS ....................................................................................................... 12
Corellas on Kangaroo Island.................................................................................................................... 12
World’s rarest snakes recovering after rat removal .................................................................................. 12
Mariana crow could become extinct in 75 years....................................................................................... 12
Sumatran tiger population higher than expected ...................................................................................... 13
Indian Island rodent eradication ............................................................................................................... 13
State of Australia’s Birds 2010 ................................................................................................................. 13
Risks of bird poisoning on Marion and Gough Islands.............................................................................. 13
Economic influence of invasive species in Seychelles ............................................................................. 14
Rodenticide baits and effects on rodents in Hawaii .................................................................................. 14
Dogs detecting treesnakes and rodents ................................................................................................... 14
Island Invaders DVD on seabird islands................................................................................................... 14
ISI newsletter ........................................................................................................................................... 15
TV series on penguins on Phillip Island.......................................................................................................15
Henderson Island newsletter and video ................................................................................................... 15
ALIENS: The Invasive Species Bulletin.................................................................................................... 16
Pacific Invasives Initiative newsletter...........................................................................................................16
Macquarie Dispatch ................................................................................................................................. 16
New Tasmanian IslandCare website being developed ............................................................................. 16
UPCOMING EVENTS .............................................................................................................................. 17
ISLANDS IN FOCUS: AUSTRALIA
Macquarie Island update – next phase planned for April
Baiting set to resume on Macquarie Island
There’s a growing sense of anticipation among the
small team from the Macquarie Island Pest
Eradication Project as the summer wanes and
preparations for the team’s departure in April step
up a notch.
Last year’s unsuccessful attempt to implement the
aerial baiting phase of the project due to extreme
weather conditions has not dampened the
enthusiasm or commitment to getting the job done.
An earlier arrival on the island will give the team
an expanded window of flying weather, both in
terms of generally more settled autumn conditions
as well as longer daylight hours.
This year’s team of 28 will be larger compared to
the team of 20 last year. The additional staff will
assist with the baiting operation, but an additional
task will be to search for and remove carcasses of
poisoned rabbits and birds that may have taken
the bait or scavenged poisoned carcasses.
More than 900 birds were killed last year as a
result of the baiting operation. A review of the
impacts of the 2010 baiting operation was initiated
by the Australian Government and a team to
search for and remove carcasses was among the
recommendations aimed at reducing impacts on
non-target species.
Justin Febey at work on the new helipad as part of
preparations for the baiting program to be undertaken this
autumn/winter (Image: Tasmania Parks and Wildlife Service).
A further measure aimed at reducing the number
of poisoned rabbit carcasses is the release of the
Rabbit Haemorrhagic Disease Virus (RHDV) on
Macquarie Island.
Project manager Keith Springer explained: ‘The
release of RHDV is a relatively low-risk option to
try to reduce rabbit numbers and thus reduce nontarget mortality from the aerial baiting phase.
While its effectiveness in the sub-Antarctic
environment is uncertain, potentially there is a lot
to gain. In fact, of the mitigation measures we can
implement, potentially RHDV could be by far the
most effective’.
Two hundred kilograms of the carrots were sent to
the island in January for distribution of the virus at
high density rabbit sites.
More of the Pestoff 20R bait has been ordered so
the team is assured of a sufficient supply of fresh
bait, following ongoing inspections of bait that
remained on the island. While the majority of the
bait on the island was in good condition early in
the year, having sufficient fresh bait was seen as
the best strategy for success, because the bait
pods won’t be reopened until winter and further
deterioration may have occurred by then,
compared to the checks undertaken over the
summer.
Skua family eating rabbit - Skuas were among the species
affected by the Pestoff 20R bait, through consuming rabbits
poisoned by the bait (Image: Keith Springer).
Another key to the eventual success of the project is the hunting dogs. While the project’s seven highly
trained springer spaniels and four labradors achieved the required certification last year, they remained with
their trainers in New South Wales and New Zealand so their fitness and training regime could be
maintained. They will now travel to the island in April, set to take up their important work in hunting surviving
rabbits as soon as the baiting is complete.
By Liz Wren, Tasmania Parks and Wildlife Service (email: Liz.Wren@parks.tas.gov.au).
Rats...Pipes...Cameras...Action! A vertical bait station and remote
camera trial on Muttonbird Island, New South Wales
Muttonbird Island (30°18’ S, 153°09’ E) is located
off the coast from Coffs Harbour, on the New
South Wales mid-north coast. The eight hectare
island became a reserve in 1971 for the
preservation of the colony of wedge-tailed
shearwaters (Puffinus pacificus) that breed on the
Island from August to May. The Island is
connected to the mainland by a 500-metre
breakwall that forms the northern wall of the Coffs
Harbour International Marina (Figure 1). The
Island provides a unique opportunity for more than
150 thousand annual visitors to view the wedgetailed shearwater colony at close quarters.
Volunteer bird banders have been monitoring a
subset of the shearwater population on the Island
for approximately 40 years, with results suggesting
a declining population of shearwaters on the
Island. Rodent predation on eggs or chicks,
although unproven, has been identified as one of
the threats to the seabird colony.
9 animals per hectare respectively, although
recent
estimates
suggest
much
higher
populations. Muttonbird Island is the only island in
New South Wales that supports a swamp rat
population. As part of the black rat control program
to protect the wedge-tailed shearwaters, the New
South Wales National Parks and Wildlife Service
has been baiting the western section of the island
since 2007. In recent years the baiting program
has been expanded with other areas partially
baited. Sporadic baiting also occurs along the
breakwall by the NSW Land and Property
Management Authority. Since swamp rats are a
similar size to the black rats they are at risk of
being poisoned. The swamp rats’ unique
occurrence on an island plus protection under
NSW legislation means that every effort must be
afforded to prevent them encountering poison
baits.
In order to address this management issue, UNE
honours student Frances Zewe, under the
supervision of Paul Meek (Department of Industry
and Investment NSW), Hugh Ford (UNE) and Karl
Vernes (UNE), set out to develop a tool that could
control the black rats, while not harming the
swamp rats.
Three sympatric rodent species occur on
Muttonbird Island: the house mouse (Mus
musculus), black rat (Rattus rattus) and swamp rat
(R. lutreolus) (Figure 2). A 2008 mark-recapture
study estimated the density of house mice, black
rats and swamp rats on the island to be 53, 6.5 &
Figure 1. Muttonbird Island in Coffs
Harbour is connected to the mainland by a
breakwall (Image: DECCW).
Figure 2. A swamp rat (Rattus
lutreolus) in the captive trial (Image:
Frances Zewe).
3
Figure 3. A remote camera image of a
pair of black rats exploring the bait
station during the field trial (Image:
Frances Zewe).
This was achieved by using remote camera
technology to trial a vertical bait station that was
based on the differences in climbing ability
between the target and non-target rat species. Bait
stations were constructed using PVC pipe cut into
a 50 cm vertical length, a 30 cm horizontal length
and two 90 degree elbow joints with a screw end
bait chamber (Figure 3). A viewing chamber was
cut from the horizontal section and replaced with
wire mesh to allow remote cameras to detect
activity inside the bait station. Captive and field
trials at three sites were conducted to determine if
the rats would enter the bait stations in both the
lab and field settings. Bait stations in the field and
lab were continually monitored using Reconyx
RapidFire infra-red remote cameras that recorded
bait station visitation and animals inside the station
walking towards the bait chamber (Figure 4). In the
laboratory the bait was weighed at the beginning
and end of each nocturnal trial to obtain a second
measure of a successful entry by a rat.
entered the vertical bait stations in the laboratory
(Figure 5), and wild black rats were recorded 32
times successfully entering the bait chamber in the
field (Figure 3). In contrast, four (18%) out of 22
swamp rats climbed the 50 cm vertical bait
stations in the laboratory but only one was
observed entering them during a 16-night trial in
the mainland study site. These results have been
encouraging and the NSW NPWS has adopted the
vertical bait station method in their most recent rat
baiting program on Muttonbird Island. This device
clearly provides a solution to locations where
sympatric rodent or non-target species occur and
trials to assess the climbing ability of other native
species are necessary. The authors in
collaboration with the Schultz Foundation in South
Australia and Primary Industries and Resources
South Australia have commenced trials to assess
if the bush rat Rattus fuscipes can climb the
vertical bait stations — results to date indicate that
bush rats are less likely than black rats to access
the bait chamber.
We hypothesised that black rats would climb the
50 cm vertical bait station, whereas swamp rats
would be excluded due to their inability or
unwillingness to climb. The results of our study
found that 11 (92%) out of 12 captive black rats
For further information, contact Frances Zewe
(frances.zewe@uqconnect.edu.au) or Paul Meek
(paul.meek@industry.nsw.gov.au).
Figure 4. Pilot trials were undertaken to evaluate different
remote cameras to monitor the bait stations in the field trial
(Image: Frances Zewe).
Figure 5. A rat visiting the bait chamber in the captive trial
(Image: Frances Zewe).
Foxes in Tasmania — an update
Results received in December 2010 from
Tasmania’s fox scat collection survey show that a
scat collected east of Forth, in Tasmania’s north,
has tested positive for fox DNA. This is the second
fox-positive scat to be identified by the University
of Canberra’s genotyping facility from Phase 3 of
the survey. Six other fox-positive scats have
already been identified from this region following
sighting reports in 2007 and 2008. Almost 1600
scats were collected during the 2010 survey,
bringing the total number of samples analysed
during this project to over 9,700. The majority of
4
the 2010 samples have now been analysed. In
total, fox DNA has been identified in 58 Tasmanian
predator scats since 2002. Fox DNA sequence
from a skull that was collected in Tasmania in
2009, was also confirmed as fox following
independent identification by researchers at the
Australian Museum. The information provided from
the strategic survey and other tactical searching is
critical to the effectiveness of the eradication
program.
For further information on the Fox Eradication
Program, see http://www.dpipwe.tas.gov.au/fox
ISLANDS IN FOCUS: INTERNATIONAL
‘Project Restore’ Taranga (Hen) Island kiore eradication
The eradication of kiore (Rattus exulans) from
Taranga (Hen) Island, off the Whangarei coast of
Northland, New Zealand, passed a major
milestone in January 2011 with gaining the
statutory required for resource consent for the
operation to occur.
access to, or use of, a resource) on taking this
seafood until laboratory testing confirms no
residue is present.
Taranga is a designated Nature Reserve due to
the high fauna and flora values, with landing only
allowed under a permit issued by DOC. Kiore
were introduced to the island and are the only
mammalian predator present. They are being
removed since their continued existence places
many threatened species at risk. Their removal
will allow the populations of many species to be
enhanced, including Tuatara, Pycroft’s petrel,
endemic native snails and native plants.
The operation is being undertaken by the
Department of Conservation (DOC, Whangarei
Area Office) in partnership with the Ngatiwai
Trust Board. Operational planning commenced in
June 2010 with the application for resource
consent to apply 9.3 tonnes of cereal bait (Pestoff 20R™ containing 0.02gm/kg brodifacoum)
from the air using 2 helicopters. The aerial
application of bait is the only practical way of
achieving eradication on this island due to the
steep / rugged terrain over much of its 509
hectares. The monitoring of sea egg (kina) and
crayfish for toxin residue after the bait drop is a
condition of the resource consent, as is a
requirement for a rāhui (a tapu/taboo restricting
Aerial application of baits has been used to
successfully eradicate kiore from the adjacent
Marotere or Chicken Islands (Coppermine,
Whatupuke and Lady Alice) in the 1990’s. Today
a huge difference in the abundance of native bird
such as the North Island Saddle Back and lizard
fauna can be observed on these islands.
Weed team searching northern faces as part of the twiceyearly weeding of the island (Image: T. Shanley).
Taranga Island (Image: Peter Mitchell).
5
Consent allows the operation to occur during the
period May 2011 to 2015 and the operational
plan is being finalised with the intent that there
will be two separate bait applications during a
fine weather window after 1 May 2011. Both the
Ngatiwai Trust Board and the Department of
Conservation see this project as a major step
forward in the conservation of Taranga.
By Keith Hawkins, Project Manager, ‘Project
Restore’, Department of Conservation, Whangarei
(email: khawkins@doc.govt.nz).
Rat Island officially declared rat free
Rat Island, a remote island in Alaska Maritime
National Wildlife Refuge, has recently been
declared rat-free (see online news article at
http://www.islandconservation.org/news/article.php
?id=14). The announcement follows two years of
field monitoring on an island where rats have
decimated native seabird populations by preying
on eggs and chicks.
cation. The giant song sparrow, previously rarely
sighted, is now commonly seen on Rat Island.
Other species expected to benefit from the rat
removal include black oystercatchers, glaucouswinged gulls, pigeon guillemots, rock sandpipers,
common eiders, red-faced cormorants and graycrowned rosy finches.
An evaluation of the higher-than-expected nontarget mortality associated with the rat eradication
effort is now available. The Rat Island Rat
Eradication Project: A Critical Evaluation of
Nontarget Mortality, by the Ornithological Council,
includes recommendations for future rodent
eradication projects that should reduce the risks to
non-target species.
Restoring the island’s habitat for native seabirds is
the most ambitious Northern Hemisphere island
habitat restoration project ever undertaken, and
the first in Alaska. The eradication of the nonnative rats took place in September 2008, and the
restoration of the island was led by Island
Conservation, The Nature Conservancy and the
U.S. Fish and Wildlife Service.
The report is available online at:
http://alaska.fws.gov/ratislandreview-final.pdf
Bird numbers have already been seen to increase,
just two rat-free nesting seasons since the eradi-
Confirming success of aerial rat eradications on Mexican islands
pest-free. In December 2009, black rats (Rattus
rattus), the only invasive mammals present, were
confirmed to be eradicated. Farallón de San
Ignacio (17 hectares) and San Pedro Mártir (267
hectares) host important seabird colonies as well
as endemic and native reptiles and bats. Both
desert islands are located in the Gulf of California,
Mexico. After two years of pre-eradication
monitoring and experiments on the target and
several native species, attending a precautionary
approach, the rat eradications were conducted in
the second half of 2007. The monitoring continued
every three months for two years. Since these
projects form part of a wide island restoration
national program, we wanted to ensure that
everything went well.
The first two Mexican islands cleared of invasive
rats via aerial broadcast of toxic bait were declared
San Pedro Mártir Island (Image: Araceli Samaniego).
6
King snake on San Pedro Mártir.
Tropicbirds on Farallón de San Ignacio.
During the absence-confirmation phase, another
rat eradication plan was prepared for Isabel Island
(82 hectares), in the Pacific Ocean, near the
mouth of the Gulf of California. Isabel, a tropical island where a previous rat eradication using bait
stations failed in 1995, is home to nine seabird and
six reptile species. The aerial eradication was
conducted in May 2009 and monitoring will
continue until early 2011.
Frigate bird on Isabel Island
(Images: Araceli Samaniego).
The stable isotopes analysis confirmed that the
rats were predating on native plants, reptiles, and
eggs and chicks of seabirds. The post-eradication
systematic monitoring shows significant recovery
results. Two years after the eradication, the king
snake and the Xantus´s murrelet were recorded
for the first time in decades on San Pedro Mártir.
Reptiles and seabirds are increasing in numbers
on Farallón de San Ignacio. The highlight is a 60
per cent increase in the number of red-billed
tropicbirds’ nests. On Isabel, one year without rats
allowed a carpet of woody seedlings to emerge,
and juveniles of the native black iguana are
evidently more abundant.
As at the last monitoring in November 2010, the
island appears to be rat free: no rat sign was found
during the intensive and extensive trapping and
the local fishermen have not had any food
gnawed.
These successful restoration projects set a
benchmark for Latin-America, as they are the first
eradications in the region that relied on the aerial
broadcast technique. The positive results are
improving not only the condition of the insular
ecosystems and several native and endemic
species but also the support, trust and involvement
of local communities, donors and authorities.
Following New Zealand general guidelines, the
eradication strategy for the three projects was
similar: two aerial applications covering the entire
island, 7–9 days apart, each one following baitsowing lines set by DGPS with a 50 per cent
overlap, using a Helicopters Otago Ltd aerial
bucket. The toxic bait (CI-25), 2 gram green pellets
with 25 ppm of brodifacoum, was fabricated and
donated by Bell Labs. These projects are led by
Conservación de Islas, a Mexican NGO, with the
support of Mexican government agencies
(SEMAR, SEGOB, CONANP, SEMARNAT and
CONABIO) and the funding of national and
international foundations. The Mexican Navy
provides valuable in-kind support, particularly with
critical logistics aspects.
By Araceli Samaniego and Alfonso Aguirre, Grupo
de Ecología y Conservación de Islas – Mexico.
For further information, email
araceli.samaniego@islas.org.mx.
7
Attempting eradication of Norway rats on Fregate Island, Seychelles
The 1995 invasion by Norway rats Rattus
norvegicus of Fregate Island in the granitic
Seychelles was one of the few opportunities to
both learn about the dynamics of a rat invasion
and also to attempt eradication during the initial
stages of an invasion — something never before
attempted. The report Attempted Eradication of
Norway Rats during Initial Stages of an Invasion
of Fregate Island, Seychelles documents some
of the lessons learnt from the 1996 eradication
attempt. At that time we did not know that the
date of invasion was July 1995; this fact only
became clear after establishing good relations
with island staff and discussing it with them. This
was only one of a set of frustrations that made
achieving a successful eradication highly
unlikely. The other problems were limited support
from the island owner and manager, delays in
obtaining appropriate materials, and restrictions
on activities due to hotel construction. Adult rats
showed extreme neophobia and detection was
really only possible using footprint tracking in
natural mud patches and dust. Feeding sign and
droppings were not seen. Live rats were rarely
seen (only two sightings). Movement of rats was
extremely limited until about seven months after
invasion when rat sign was increasingly
frequently found at further distances (greater
than 500 metres). Juvenile rats appeared to be
easily trapped. My personal view is that it is
possible to eradicate an invading population of
rats provided that: 1) it is less than 6 months post
invasion, 2) that appropriate material and funding
is available, 3) the eradication team has the skills
and authority to undertake the work, and 4) that
appropriate techniques are used — ideally, not
using artificial structures such as bait stations
and trap covers. A combination of good traps and
low-wax poison baits are the ideal eradication
tools for this kind of activity.
The full 1997 technical report is available online
at http://www.feral.org.au/attempted-eradicationof-norway-rats-fregate-island-seychelles/
The
report was also the basis for a paper: Thorsen M,
Shorten R, Lucking R and Lucking V (2000). The
invasion of Fregate Island by Norway rats Rattus
norvegicus, the invasion, subsequent eradication
attempts, and implications for the island’s fauna.
Biological Conservation 96:133-138.
By Mike Thorsen, restoration biologist, St Helena
National Trust, St Helena, United Kingdom (email
mike.esr@xtra.co.nz).
IA CRC workshop on rabbit eradications on islands
The Invasive Animals CRC held an international workshop in
February last year aimed at improving the efficiency of rabbit
eradications on islands. The proceedings report has just been
published and summarises the invited papers, main
discussions and recommendations of the workshop. The report
also includes a stand-alone appendix on ‘Current agreed best
practice on rabbit eradication on islands’.
The proceedings are available online at
http://www.feral.org.au/improving-efficiency-of-rabbiteradications-on-islands/. Hard copies are also available from
the CRC (email us at contact@invasiveanimals.com).
8
Progress on South Georgia Habitat Restoration Project
Following public consultation, the Government of
South Georgia and the South Sandwich Islands
(GSGSSI) gave consent for the rodent-eradication
project to start fieldwork this month. The project will
be undertaken in two phases over a period of five
seasons, with the first phase involving a trial bait
drop. Latest news is described on the South
Georgia Heritage Trust website
(http://www.sght.org/latestnews.htm) and in the
South Georgia newsletter, available at
http://www.sght.org/documents/HRnewsletterDec10
.pdf
Rehabilitating the Seychelles
A 12-page brochure (English and French versions
available) has been produced on the results of the
Seychelles FGEF (French Global Environment
Facility) project 'Rehabilitating Island Ecosystems
— Eradication of Invasive Exotic Species and
Reintroduction of Threatened Endemic Species.'
For further information, see
http://www.islandconservationsociety.com/conserv
_ffem.html or contact Gérard Rocamora (email
whiteye@seychelles.net).
FEATURE ARTICLE: Appreciating eradications from a tourist’s
perspective — a visit to Antarctic islands
In December 2010 I boarded the Heritage
Expeditions ship, Spirit of Enderby, as a tourist on
a trip including landings on the Auckland Islands,
Macquarie Island, Campbell Island and the
Antarctic coast. The subantarctic islands of New
Zealand and Australia are sometimes called ‘the
Galapagos of the Antarctic’ because of the unique
biodiversity of their wildlife and vegetation. Many
of the land birds have evolved endemic
subspecies on these small islands. These islands
are also the major breeding grounds for millions of
seabirds, including many penguin and albatross
species, and also marine mammals. The islands
are also distinctive for their megaherbs, which are
wildflowers with huge leaves and large brightly
coloured flowers that only grow here.
tories, tourist impacts are regulated through
restrictions on numbers. Only 600 visitors a year
are allowed on New Zealand’s subantarctic islands
and 500 on Australia’s Macquarie Island. There
are further strict controls on where visitors can
land and which parts of the islands are accessible.
There were 48 passengers on our ship, including
photographers and travel writers, but mostly
tourists, many of whom knew little about
Antarctica. Expedition staff included several
professional wildlife ecologists who presented
talks on the biodiversity and history of the places
we visited. These talks had a strong focus on the
threats posed by past introductions of exotic
species and the current threats posed by visiting
tourists. Passengers were told not to approach
wildlife any closer than five metres to minimise
disturbance. The need for strict quarantine
measures to ensure visitors would not accidentally
introduce exotic seeds or diseases was explained.
All the passengers’ clothing, backpacks and
footwear was checked for seeds and soil. All
footwear was scrubbed and disinfected at each
island before leaving the boat and on return to the
boat.
The subantarctic islands of New Zealand and
Australia are all nature reserves and are all listed
as World Heritage Sites. Although ship-based
Antarctic tourism has greatly expanded over the
past two decades, most tourism is concentrated
around the Antarctic Peninsula and associated
sub-Antarctic islands off South America. Although
several companies operate tours to the Australian
and New Zealand subantarctic and Antarctic terri-
9
Mary with fur seal, Enderby Island (Image: Diana Honey).
The first Island where we landed was Enderby
Island, a 710 hectare gem in the Auckland Islands
(New Zealand). On Enderby, cattle were removed
and rabbits were eradicated in the early 1990s. At
that time the island’s vegetation was largely
denuded. On our visit, nearly 20 years later, the
native vegetation had largely recovered, and we
saw healthy tussock grasses and megaherbs in
peak flower. We walked around the entire
circumference of Enderby Island and although we
tried to observe the five-metre rule, if we sat
quietly, curious seals and birds came right up to
us. It was a wildlife photographer’s dream! As well
as an impressive number of New Zealand sea
lions, we had close encounters with yellow-eyed
penguins, southern royal and light-mantled sooty
albatrosses, Auckland Island shags, subantarctic
skuas, Antarctic terns, flightless Auckland Island
teal,
double-banded
plovers,
red-crowned
parakeets, tomtits and Auckland Island snipe.
The next day we visited the main Auckland Island
which is 510 km2. Although cattle, sheep, goats,
dogs, possums and rabbits were removed in the
1990s; feral cats, pigs and mice remain and we
saw a lot of pig rooting. Unfortunately feral pigs
have largely eliminated megaherbs from Auckland
Island. The pigs root up large areas of tussock to
eat roots and native worms and they also prey on
the eggs and young of many bird species. The
impact of feral cat predations was also evident,
with a number of land and sea birds that we saw
on Enderby Island, absent from Auckland Island.
The next island we visited was Macquarie, which
is under Tasmanian jurisdiction. Macquarie Island
Double banded plover with flowering megaherbs, Enderby
Island (Image: Mary Bomford).
is 34 km long and 5 km wide. Here again,
introduced species are wreaking havoc. Staff from
the research base on Macquarie Island kindly
guided us around the parts of the island open to
visitors, and explained plans for the proposed
eradication attempt on rodents and rabbits in the
autumn and winter of 2011.
We visited the huge royal penguin colony behind
Sandy Bay where hundreds of thousands of birds
had chicks. Unfortunately the vegetation
surrounding this colony is largely devastated by
rabbit grazing. Even during the day many rabbits
could be seen. Although the 2010 attempt to
eradicate rabbits and rodents on Macquarie failed
due to exceptionally bed weather, hopefully the
2011 attempt will be successful. We could already
see vegetation recovery in the area where rabbit
poisoning occurred before the 2010 eradication
attempt was abandoned. Rabbits have caused
devastating damage to the island’s flora, which
has resulted in several big land slips. The good
news is that rabbit exclosures, constructed by
Tasmanian Department of Primary Industries and
Water, show that when rabbit grazing is prevented,
the vegetation recovers well.
Our final destination was Campbell Island, which is
the largest island (11,300 ha) from which rodents
have ever been eradicated — Norway rats (Rattus
norvegicus) were eradicated here in 2001.
Fortunately, Campbell Island never had rabbits
and sheep and cattle were all removed about 20
years ago. The megaherbs and tussock vegetation
are once again flourishing. We were able to hike to
North-West Bay and also to climb Mt Honey —
10
Rabbits ‘being rabbits’ near royal penguin colony, Macquarie
Island.
and spent hours photographing the displays of the
Southern Royal Albatross that nest on the island.
Being a wildlife ecologist, my focus was on the
impacts of exotic animals, rather than introduced
plants, but even I recognised many exotic plants
on the islands we visited. Unfortunately the
eradication of weeds has not had the same focus
or success as vertebrate eradications, either here
or elsewhere in the world.
Hopefully, once the vertebrate pests are
eradicated from these islands, more attention can
be paid to eradicating introduced plants, and in the
meantime to ensuring that no new exotic plants
establish.
Although I had a wonderful time photographing
wildlife on this trip, the stark contrasts between
islands with and without introduced vertebrate
Rabbit exclosure showing plant regeneration, Macquarie
Island (Images: Mary Bomford).
pests was one of the most striking features of my
subantarctic experience. Enderby Island and
Campbell Island illustrate huge benefits that come
from the eradication of introduced vertebrates,
even when they have been present for many
decades. Hopefully Macquarie Island will soon be
rid of rodents and rabbits. And it will be wonderful
if cats and pigs can be eradicated from Auckland
Island, before they do much more damage, but
unfortunately no funding is available for this yet.
Even though these are fragile ecosystems, it was
so encouraging to see how quickly the vegetation
and wildlife has recovered following the success of
previous eradication campaigns.
By Mary Bomford, wildlife ecologist and consultant
for the Invasive Animals CRC
Displaying Southern Royal Albatross with flowering megaherbs,
Campbell Island.
11
Squabbling royal penguins, Macquarie Island (Images:
Mary Bomford).
RECENT NEWS & PUBLICATIONS
Corellas on Kangaroo Island
Up to 1000 little corellas may have to be culled on
Kangaroo Island. Island authorities have been given
state government approval to cull the native birds,
which are said to be stripping trees and forcing
endangered bird species out of their nesting areas.
The resident population is only about 200 birds, but
many more arrive from the Australian mainland in
summer, attracted by crops on the island.
From The Advertiser 1 November 2010 at
http://www.news.com.au/corellas-forceendangered-species-out-of-nesting-areas/storye6frea83-1225945850264?from=public_rss
World’s rarest snakes recovering after rat removal
Reportedly the rarest snake species in the world,
the Antiguan racer, is recovering from near
extinction. The snakes live on Great Bird Island, off
the coast of Antigua in the West Indies, where many
had been killed by imported rats (the species was
previously also on Antigua, but numbers were
devastated by introduced mongooses.) Rats have
been removed from 12 of Antigua's offshore islands
and the benefits to native wildlife have been evident.
Racer numbers have increased ten-fold, from a low
of 50 in the 1990s to over 500. Caribbean brown
pelicans and white-crowned pigeons have also
become more numerous.
From New Scientist news, 2 November 2010, at
http://www.newscientist.com/blogs/shortsharpscienc
e/2010/11/rarest-snake-back-from-thebri.html?DCMP=OTC-rss&nsref=online-news
Mariana crow could become extinct in 75 years
The critically endangered Mariana crow Corvus
kubaryi could be extinct in 75 years if people do not
intervene. The extinction could happen almost twice
as soon as previously believed. The crow lives
exclusively on Rota Island (a U.S. territory in the
western Pacific Ocean near Guam) and an
uncontrolled increase in feral cats is reputedly their
biggest threat.
Survival rates in 97 crows were tracked between
1990 and 2010, showing only 40 percent of fledgling
crows made it through their first year. Previously,
biologists believed that the first-year survival rate of
Mariana crows was much higher. A population
model factoring in the estimated number of existing
crows (330) with the 40 percent first-year survival
rate, average number of fledglings per nest and fert-
ility of female birds was used to predict the number
of years to extinction.
The crow's extinction could be prevented by helping
fledgling birds survive their first year, through a
captive rearing program. According to the
researchers’ population model, if fledgling survival
can be boosted from 40 to 70 percent, the Mariana
crows will persist.
From EurekaAlert, 20 Dec 2010 at
http://www.eurekalert.org/pub_releases/201012/uow-wim121710.php and article published in
Bird Conservation International. For more
information, see UW's Rota Avian Behavioral
Ecology Program: at
http://depts.washington.edu/rabep/index.html.
12
Sumatran tiger population higher than expected
Sumatran tiger distribution studies have revealed
that Sumatra hosts possibly the second largest
tiger population on earth (after India). However,
while tigers still occupy a large majority of the
remaining available habitat in Sumatra, only 29%
of this habitat is protected. The survey also
revealed that tigers occupy a great diversity of
ecosystems from sea level in coastal lowland
forests, to 3200 meters above sea level in high
mountain forests. Researchers said if the
Indian Island rodent eradication
Indian island (168 hectares) in Fiordland, New
Zealand, is home to many threatened species
including kiwi, kaka and Fiordland crested penguins.
A rodent eradication operation has recently been
carried out on the island, using aerial-baiting
techniques. The iconic island has also had stoat
and deer control programs running since 1999. The
Department of Conservation, contracted by the
Fiordland Conservation Trust, is now planning to
manage biosecurity on the island until it can be
officially declared rodent-free.
population is indeed as large as the new survey
suggests, then actions and support should be
mobilised to conserve the tigers.
The research is to be published in a special issue of
Integrative Zoology on tiger conservation and
research methodologies.
From Eureka Alert 6 Dec 2010 see
http://www.eurekalert.org/pub_releases/2010-12/wsm120610.php
Monitoring of the island’s stoat and rat traps will
continue over the next two years. Reinvasion will be
managed through the use of permanent bait
stations and kill-traps on Indian Island and the small
surrounding
islands.
A
successful
rodent
eradication could lead to the release of other
threatened species, such as mohua.
From Fiordland Coastal Newsletter October 2010.
For more information see
http://www.doc.govt.nz/aboutdoc/news/newsletters/fiordland-coastal-newsletter/
State of Australia’s Birds 2010
Birds Australia issued the 2010 State of Australia's
Birds (SOAB) and the theme was islands. The
State of Australia's Birds reports are overviews of
the status of Australia's birds, the threats they face
and the conservation actions taken.
The report is available on the Birds Aust website:
http://www.birdsaustralia.com.au/soab/state-ofaustralias-birds.html
For further enquiries and requests for hard copies
contact Julie Kirkwood (email
j.kirkwood@birdsaustralia.com.au).
Risks of bird poisoning on Marion and Gough Islands
‘Risk assessment of birds foraging terrestrially at
Marion and Gough Islands to primary and
secondary poisoning by rodenticides’, by R
Wanless, J Cooper, M Slabber and P Ryan (2010)
in Wildlife Research 37(6). See abstract at
http://www.publish.csiro.au/paper/WR10005.htm
This paper assesses the risk of poisoning by
rodenticides to lesser sheathbills, Gough
moorhens and Gough buntings at Marion and
Gough Islands. It recommends that populations for
reintroduction be taken into temporary captivity
before and during a poison-bait exercise as a
precautionary measure.
13
Economic influence of invasive species in Seychelles
‘Economic valuation of the influence of invasive
alien species on the economy of the Seychelles
islands’ by P Mwebaze, A MacLeod, D Tomlinson,
H Barois, and J Rijpma (2010) in Ecological
Economics.
See
http://www.bioecon.ucl.ac.uk/11th_2009/Mwebaze.
pdf
Loss of biodiversity as a result of invasive alien
species could result in major negative economic
impacts for the Seychelles. This paper assesses
the value of impacts of invasives on biodiversity,
natural resources and the national economy, using
the principles of total economic value (TEV).
Tourists indicated willingness to pay up extra
money on top of their usual expenditures to fund
conservation policy. Approximately US$0.25
million per year is currently spent on invasive alien
species control. The economic damage associated
with just four key species is around US $21 million
per year. Comparing the benefits with the costs
involved indicates that the policy of eradicating
invasives is economically justified.
Rodenticide baits and effects on rodents in Hawaii
‘Efficacy of rodenticide baits for the control of three
invasive rodent species in Hawaii’, by W Pitt, L
Driscoll and R Sugihara (2010) in Archives of
Environmental Contamination and Toxicology.
Abstract online at
http://www.ncbi.nlm.nih.gov/pubmed/20552335
The efficacy and palatability of nine commercial
rodenticide bait formulations were tested on rats
(Rattus exulans and R. rattus) and house mice
(Mus musculus). Generally, rodenticides were more
effective against mice than for either of the rat
species, and efficacy was higher for secondgeneration anticoagulants. Bait acceptance was
generally lowest for the acute rodenticides and
products that were not well accepted resulted in
lower mortality rates. Rodenticides currently
registered for use in Hawaii performed less
effectively than other products that are available
but not yet registered there.
Dogs detecting treesnakes and rodents
Two recent articles on detector dogs may be of
interest:
1. ‘Canine detection of free-ranging brown
treesnakes on Guam’, by J Savidge, J Stanford,
R Reed, G Haddock and A Yackel Adams
(2011) in New Zealand Journal of Ecology
35(2). The full article is available online at:
http://www.nzes.org.nz/nzje/new_issues/NZJEcol_
SavidgeIP.pdf
2. ‘The success of using trained dogs to locate
sparse rodents in pest-free sanctuaries’, by A
Gsell, J Innes, P de Monchy and D Brunton (2010)
in Wildlife Research 37:39–46. The abstract is
available online at
http://www.publish.csiro.au/paper/WR09117.htm
Island Invaders DVD on seabird islands
A DVD entitled Island Invaders has been produced by A Hoffman, C Mulder and SEAPRE Research
Coordination Network. It tells the story of seabird islands and the invasive species that threaten them. Shot
over a period of three years, the 28-minute DVD consists largely of interviews with SEAPRE scientists and
footage of seabird islands. It includes:
 the importance of seabird islands
 impacts of predators on seabirds and
their islands
14
 predator eradication
 island recolonisation and restoration
 the importance of community involvement to seabird island conservation.
For more information, see http://www.seapre.uaf.edu
ISI newsletter
Invasive Species International (ISI) has just issued the 3rd issue of its newsletter, ISI News (see
http://www.isinz.com/newsletter/).
For further information see http://www.isinz.com or contact ISI manager Alan Saunders (email
saundersa@landcareresearch.co.nz).
Television series on penguins on
Phillip Island
The ABC recently produced a TV series on the internationally
renowned little penguins on Phillip Island, Victoria. Penguin
Island uses the latest underwater satellite tracking and video
surveillance to follow the lives of several penguin families.
Filmed over a year, with six 30-minute episodes, the series
records the activities and adventures of penguins as a team of
rangers and scientists monitor and protect them through the
hottest summer on record.
For further details, see the ABC website
http://www.abc.net.au/tv/penguinisland/series/default.htm
Henderson Island newsletter and video
The 2nd and 3rd editions of Henderson Island News
have been issued (Sept and Dec 2010) —
newsletters of the Henderson Island Restoration
Project on Henderson Island’s World Heritage
Site. The project aims to remove rats from the
island to save endemic species such as the petrel.
The Sept newsletter contains details of UNESCO's
recent decision, an update on progress, and new
photographic evidence of rat impacts. The
December issue contains details of the provisional
decision to proceed with the operation in 2011*, a
report on the islands of the Pitcairn group that
have already been restored, and some DEFRA
funding news.
See http://www.rspb.org.uk/hendersonisland
Little penguins (Image: M Kuhn, flickr)
*The Royal Society for the Protection of Birds
(RSPB) has provisionally decided to carry out the
restoration project in August 2011, contingent upon
raising a further £380,000 by July 2011, and the
securing of an appropriate operational vessel. The
proposed rodent eradication operation will save the
endangered Henderson petrel from extinction and
preserve the island’s World Heritage values.
£1.32m has so far been pledged towards the £1.7m
total cost of the operation. Two joint operational
managers have also been provisionally appointed.
Further details, plus a new video showcasing the
wildlife of Henderson Island and the devastating
impacts of rodent predation, can be found online at:
http://www.rspb.org.uk/news/details.aspx?id=26247
6.
For more information contact the project’s
coordinator Jonathon Hall (email
Jonathan.Hall@rspb.org.uk).
15
ALIENS: The Invasive Species Bulletin
Issue Number 30 of ALIENS, the bulletin of the
IUCN /SSC Invasive Species Specialist Group
(ISSG) has recently been published. Articles
include a review of eradications of invasive birds
on islands of the world, a report on
chytridiomycosis disease, an interview with the
head of the LIFE program of the European Union
(including
raccoon
dog
management
in
Scandinavia) and work in China collecting
information on around 520 alien species.
The bulletin is available online at
http://www.issg.org/publications.htm
Pacific Invasives Initiative newsletter
The December 2010 issue of PII News has been produced, and is available on the PII website at
http://www.issg.org/cii/pii/
Macquarie Dispatch
Issues 6 and 7 of ‘Macquarie Dispatch’, the newsletter of the Macquarie Island Pest Eradication Project,
have been released. They are available online at: http://www.parks.tas.gov.au/index.aspx?base=13001
New Tasmanian IslandCare website being developed
Tasmania's small offshore islands provide refuges
for twenty species of seabirds and three species of
seals - breeding sanctuaries primarily free from
predatory mammals, disturbance and pollution.
Many are also places of cultural significance. Such
small discrete ecosystems are particularly
vulnerable to damage and destruction caused by
the introduction of feral plant and animal species,
fire or direct human disturbance. We need to care
for these places to help ensure that they continue
to harbour a diversity and abundance of fauna and
flora.
IslandCare2 is a web project that acts as a portal
for environmental information on Tasmanian
islands. The new web site is expected to become
operational shortly. This web site will provide
opportunities to contribute information to existing
Wikipedia pages (for individual islands) as well as
via a companion Facebook page. Information on
how to join existing friends groups for Tasmanian
islands will be provided, as well as how to find key
documents or other information related to
Tasmanian islands. IslandCare is a partnership
project of Wildcare, Friends of the Bass Strait
Islands, the Tasmanian Conservation Trust (TCT)
and Birds Tasmania. This project builds on an
earlier web project also called IslandCare, a
project initiated by the Marine & Coastal
Community Network and formally hosted on the
Tasmanian Parks Wildlife Service web site.
Funding for the revamped web site is provided by
Caring for Our Country in the form of a Community
Action Grant
The new web site will be able to be accessed via
the Wildcare home page when completed. See
http://www.wildcaretas.org.au/pages/home.php
For further information contact Project Officer
Christian Bell (email islandcare2@gmail.com).
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UPCOMING EVENTS
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14th Wildlife Damage Management Conference. Nebraska City, USA, 17–22 April.
15th Australasian Vertebrate Pest Conference. Sydney, Australia, 20–23 June 2011. [See
http://www.avpc.net.au/] Note: John Parkes and Elaine Murphy are organising a symposium on
'Island pest eradications’. ABSTRACTS CLOSE FEB 28
8th European Vertebrate Pest Management Conference. Berlin, Germany 26–30 September.
BIOLIEF 2011 - 2nd World Conference on Biological Invasions and Ecosystem Functioning. Mar
del Plata, Argentina, 21–24 November 2011. [See http://www.grieta.org.ar/biolief/]
Ecological Society of Australia annual conference. Hobart, Tasmania. 21–25 November.
25th International Congress for Conservation Biology. Christchurch, New Zealand, 29 Nov–2 Dec
2011.
We hope you found this newsletter interesting and informative. Thank-you to everyone who contributed to
this edition.
Our next newsletter will be due out in August 2011.
If you would like to contribute to the next newsletter, please contact Elaine Murphy (emurphy@doc.govt.nz)
or Wendy Henderson (wendy.henderson@invasiveanimals.com).
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