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Strzelecki Koala Mapping Project Completed
September 2005 (click here)
STRZELECKI KOALA ENDANGERED
Of major concern due to the logging and clearing activities of both
Hancock Timber Resource Group and PaperlinX is the long term survival of
populations of the Strzelecki and South Gippsland Koalas whose entire
habitat is now owned by these companies.
An investigation carried out by Dr Bronwyn Houlden, School of Biological
Science,
University of New South Wales, 20th March 1997 and 6th April 1998
confirmed that the
genetic pool of these koalas has not been compromised. Dr Houlden
indicates that on a
national basis koalas generally are not considered to be threatened. She
advises that this
assessment has unfortunately led to an extremely simplistic view of
conservation of
biodiversity in the species.
Through extensive analysis by herself and her collaborators she has revealed
that the species is composed of highly differentiated populations with
low levels of gene flow between populations throughout their range.
The Strzelecki Koala population constitutes a separate management unit
and is significant in terms of management of biodiversity on a regional
and state basis. Dr Houlden found that the Strzelecki Ranges had the
highest level of genetic variation, of any Victorian population she
has analysed. This is important, given the low levels of genetic variability
found in many populations in Victoria, which have been involved in the
translocation program.
Road hit female koala with
broken jaw. Had to be euthanised after 6 weeks. Urgent research is required
to determine breeding populations, location and numbers. Logging seriously
impacts on long term populations of this animal.
The Strzelecki koala population has high levels of genetic variability
which have been
detected by rare and unique genetic markers. These animals are
statistically significantly
differentiated from other Australian populations and therefore
constitute a separate
management unit. Because biodiversity in the species as a whole is
dependent of
conservation of populations throughout the species range, the Strzelecki
Ranges
population, together with the South Gippsland population is nationally
significant as
well. The lack of genetic diversity amongst Australian koalas could be
critical to the
survival of the species as a whole.
"My results suggest that the conservation of South Gippsland and
Strzelecki Ranges
population is of local, State and National significance for conservation
of biodiversity in
koalas, and managers and landholders should ensure that enough habitat
is protected
and/or available for the populations to maintain an effective population
size that is
viable." Dr Bronwyn Houlden.
It remains unclear what Hancock intends to do in regard to forest management
plans regarding this unique animal.
10 kilo male Strzelecki Koala
which was recently attacked by dogs. This koala had to be euthanised
after 7 weeks.
HISTORIC DECISION FOR KOALA. 9th May, 2000
US GOVERNMENT DECLARES THE KOALA AS THREATENED ACROSS ITS ENTIRE RANGE
The koala was today listed under the US Endangered Species Act as threatened across its entire range.
The listing is the culmination of nine years intensive research and scientific submissions to the US Government by the Byron based Australians for Animals Inc. and the US based Fund for Animals.
Ms Arnold, Co-ordinator of Australians for Animals said:- " This is the second time in history that the US Government has moved to save the koala.
" The Australian State and Federal Governments are to be condemned for their total and explicit failure to protect our unique wildlife heritage. Although my group is delighted with this victory, it may well be a
pyrrhic one for koalas unless the destruction of native forests by the timber industry is brought to an immediate halt. '
" Scientists who supervised the three extensive scientific submissions we presented to the US Government were quite specific in their affidavits as to the threats to koalas represented by the timber industry."
Dr Frank Carrick, University of Queensland said: " The koala is almost extinct in the Southern half of NSW. Even these survivors continue to be threatened by intensive forestry operations such as clearfelling of the Southern NSW forests for woodchip exports.
" Koalas in the Northern part of NSW - face the twin impacts of loss of habitat to residential development for a rapidly expanding human population and unsustainable use of the remaining forests. Away from the coast, the most substantial western populations of koalas in NSW are facing increasing threats from more intensive exploitation of the remaining forests."
Professor Tony Norton of RMIT, Melbourne, said in his affidavit: ' In my opinion, a number of populations across the species' range, particularly in NSW and Victoria, could become extinct before the end of the century if identified threatening processes such as habitat clearance and modification are not adequately controlled."
Australians for Animals has presented detailed evidence to the US Government of the massive tree clearing in Queensland which continues in that state. This clearing has had a disastrous effect on remaining koala habitat there. Ms Arnold said: - ' The final straw to koalas is the destruction of native forests authorised by state and federal governments under the Regional Forest Agreements.
" I say to Minister Robert Hill in response to his press release re:koalas ' In your dreams Robert ' "To dismiss the sheer extent of scientific evidence presented to the US Government when he knows full well that the basis of listing under the Endangered Species Act (US) relies entirely on science is scandalous. " The continued refusal of the State and Federal governments to protect koalas and their habitat is a global disgrace and only continues to underline the appalling international environmental record that the
Howard Government has earned. " With the Olympic Games just months away, the world focus will now be
trained on Australia and its unique wildlife. The lack of protection for the gentle koala will disgust many people."
For further information:
Call Sue Arnold, Co ordinator, AFA 61 2 6684 3769 mobile : 0427 257
491.
Dr Frank Carrick, Uni of Queensland phone:61 7 3365 2466
Professor Tony Norton, RMIT, 61 3 9925 3279
AUSTRALIANS FOR ANIMALS.
P.O. Box 673, BYRON BAY NSW 2481
Phone: 61 2 6684 3769
Fax: 61 2 6684 3768
Email: arnolds@mullum.com.au
http://www.australiansforanimals.org.au
Reg. Charity No. CFN 12644
FRIENDS OF THE EARTH PRESS RELEASE, MAY 11TH 2000
Legislation Means Trouble for John
Hancock
Yesterday's historic listing of the koala under the US Endangered Species
Act could mean major problems for John Hancock, one of the United States'
major insurance companies. In November 1998, the Victorian Plantation
Corporation was sold by the Victorian State Government to Hancock Timber
Resources Group (HTRG) for $500 million and renamed Hancock Victorian
Plantations (HVP). The sale was not limited to plantations. At least
20,000 hectares of native forest in the Strzelecki Ranges, located 2
hours drive east of Melbourne were included in the sale.
The Strzelecki Ranges are the only known habitat for the Strzelecki
and South Gippsland Koala. These koalas are of local, state, national
and international significance due to their high level of genetic variability.
Long term survival of these koalas is dependent on managers and landholders
ensuring that habitat is protected and /or available for the koalas
to maintain an effective population size. This means the protection
of a mix of species including old growth mountain ash, blue gum, grey
gum and messmates. These trees are currently being targeted for destruction
by Hancock Timber Resource Group, as they expand their plantations by
logging native vegetation. Despite four years of monitoring of Hancock
operations by local conservationists, Hancock continue to log the remaining
habitat of the koalas.
"Under the US Endangered Species Act US companies involved in the destruction
of Endangered species habitat can be prosecuted under US law. This factor
alone will be a major problem for investors in Hancock Victorian Plantations"
said Friends of the Earth Forest Campaigner Anthony Amis. "We have been
making good links with US NGO groups for some time now and this recent
legislation is definitely something that we will be making the most
of. Hancock have been ruthless in their logging in the Strzelecki's.
We will be sending that message to hundreds of groups in the US. This
will be a major headache for Hancock, especially in the lead up to the
Olympic Games, where John Hancock are a major sponsor. Our message to
Hancock is stop the destruction of native vegetation in the Strzelecki's.
People from around the world will not be impressed when they find out
that Hancock are destroying what is possibly the most genetically important
koala habitat in the world" Mr Amis concluded.
FRIENDS OF THE EARTH PRESS RELEASE, 27/5/00
Hancock Timber Resource Group Representative Witnesses First Hand The
Logging Of Koala Habitat In Strzelecki Ranges Of South East Australia.
On a recent visit to Australia, an American based representative of
Hancock Timber Resource Group (HTRG), (HTRG is a subsidiary of John
Hancock Financial Services), representatives of Smartwood (a U.S. based
forest accreditation company) and local residents witnessed first hand
the logging by Hancock Victorian Plantations of native vegetation and
koala habitat in Victoria's Strzelecki Ranges.
A field trip, to an active coupe site in the Strzelecki Ranges on May
24, revealed the felling of koala habitat (koala scats were found).
A koala was observed perched in a tree as trees were being felled in
very
close proximity.
There have been no ecological audits or clear delineation of native
vegetation and plantations marked on any of these sites. Locals have
voiced concerns for many years over the destruction of the koala habitat,
which is particulary relevant for the Strzelecki Ranges, as this colony
is the only endemic koala population remaining in Victoria. All other
koala populations are the result of translocation programs.
The conversion of native forest into plantations by Hancock Victorian
Plantations is an ongoing issue and poses the most significant threat
to the survival of this unique Australian animal.
Spokesperson for Friends of the Earth/Native Forest Network Anthony
Amis said "Hancock's claims in the United States that they are
not logging native native forest and koala habitat have been proved
to be a
falsehood. This recent episode does not in any way validate Hancock's
claim of legitimate logging of plantations."
Earlier this month Australians for Animals successfully lobbied for
a historic decision in the United States when the United States Government
declared that the koala was listed under the US Endangered Species Act
as being threatened across its entire range.
LATROBE VALLEY EXPRESS. 29 MAY 2000
P1+2.
City Bid to Protect Endangered Koala
Latrobe City is stepping up its campaign to lobby the federal and state governments to declare the Strzelecki or Gippsland Koalas an endangered species. Council wants to prevent what Friends of the Gippsland Bush
alleges is the continued landclearing of the koala's habitat.
The koalas believed to be one of the few pure bred species of fauna left in Australia, have been declared an endangered species by the United States Government, but they have yet to receive the same status from the
Australian Government. Government officials hit out at the US earlier this month over the move, describing it as scaremongering and irresponsible.
Minister for the Environment Robert Hill accused his US counterparts of ignoring conservation and wildlife management plans already in place as well as statistics on koala numbers. However Latrobe City Mayor Tony Hanning said both state and federal governments needed to take responsibility for the protection of the genetically and geographically unique koalas.
The protection of the koalas forms part of Latrobe City's bio-diversity conservation policy contained in the environmental planning scheme, released in March this year. "Local government is not powerless, we're
empowered under state legislation to protect native vegetation," Cr Hanning said. "But we can't do it alone, we need state and federal intervention, although both state and federal governments could not stand up and claim to be environmental to any degree."
Negotiations between the city and Hancock Victorian Plantations are now into their sixth month over a December recommendation by council to lobby the company to "encourage and promote a sustainable timber industry", a key plank in ensuring the survival of the Gippsland Koala according to Cr Hanning.
Friends of the Gippsland Bush secretary Suzie Zent said the exclusion of the Strzelecki Ranges on the recently finalised Regional Forestry Agreement had left the future of the koalas under threat. "There is no
effective mechanism of legislation in Victoria which protects our unique koala," she said. "The majority of the Strzelecki Koalas are on private property, the bulk of which is owned by Australian Paper Plantations
(Amcor) and Hancock. "We believe these koalas are the last remaining endemic species in Victoria and probably Australia."
However, in a metropolitan newspaper report earlier this month, Hancock Victorian Plantations chief executive officer Kevin White claimed 18,000 hectares of forest had been set aside from logging pending a joint community groups biodiversity study.
That claim met a cool response from Australians for Animals co-ordinator Sue Arnold, who said conservation organisation Friends of the Earth had confirmed the koala's habitat was under threat. She described the current land clearing as a "national tragedy", adding the koalas were like "precious museum pieces; if we had a living museum, these koalas would be part of it".
"The issue isn't the number of koalas, it's the habitat and without their habitat, the koalas will die", she said. "Koalas are uniquely adapted to local ecosystems. They can't move on and take a holiday into other parts of Victoria. They die without their trees. Once you start to clear, the forest becomes sick. Koalas get stressed if their trees go and that stress can kill them".
Rare Tiger Quoll Spotted in Ranges.
The endangered marsupial, the Spotted-Tailed Quoll, also known as Tiger
Quoll, has been sighted in the Dingo Creek region in the Strzelecki
Ranges. Department of Natural Resources and Environment flora and fauna
staff have collected definate hair samples, confirming a positive sighting
reported to its Yarram office.
The animal is listed as endangered in Victoria and is listed under
the Flora and Fauna Guarantee Act. DNRE Gippsland region flora and fauna
manager Mike Timpano was excited about the find, the first positive
sighting in the Strzelecki Ranges since the 1960's. "We will work
closely with private property owners and Hancock Victorian Plantations
(where the hair samples were found) about on-going preservation,"
Mr Timpano said.
He said the next stage of the process was to trap the species, which
would lead to determining the size of the population, sexes and future
plans. The project started after a reported sighting which led to "hair
tubes", used to collect mammal hairs, being distributed throughout
the Dingo Creek site.
Samples of hairs collected were identified under a microscope, with
one "definite" and one "probable" record of Tiger
Quoll. Mr Timpano said suitable time for trapping was between May and
july while males were active prior to breeding, which meant there was
a strong probability confirmed results could be known soon. "Cage
traps will be set with the appropriate bait in place and checked regularly,"
he said. "We will continually assess the situation and determine
the best methodology, with the help of experts in the field, for finding
and preserving the animal within the habitat."
The Tiger Quoll is mainland Australia's largest marsupial carnivore,
which was widespread throughout southern and eastern Victoria when Europeans
first arrived. Mr Timpano said its distribution was now fragmented,
with strongholds throughout New South Wales and eastern Victoria, common
in Tasmania, but extinct in South Australia . . . The species inhabits
a variety of forest types and coastal heathland throughout its range,
typically favoring moist forest environments.
FRIENDS OF THE EARTH PRESS RELEASE, 27/05/00
Alarm Bells Ring Over Forestry Memorandum
Environmental organisation , Friends of the Earth, today questioned the Memorandum of Understanding (MOU) between Hancock Victorian Plantations and the Australian Koala Foundation (AKF) saying that the MOU would not be worth the paper it was written on if local environment groups and experts on the Victorian koala were not properly consulted. Spokesperson for FoE Forest Network Anthony Amis said "It seems very odd that both Hancock and the AKF have so far avoided consulting with local environment groups over this issue, particulary Friends of the Gippsland Bush and local residents who have many years experience about these matters. It would appear that AKF are now cashing in on all the hard work that many locals have done for years trying to protect the Strzelecki koala".
The Memorandum signed earlier this year provides a framework for obtaining supposedly scientifically credible data on koala populations, critical habitat and future habitat needs. In a press release issued on the 2nd of October by HVP,it states that field studies would begin on the 2nd October, headed by AKF's John Callahan, along with zookeepers from five major North American zoos: Toronto, San Francisco, Bergin, San Diego and Disney's Animal Kingdom. Wayne Marion, wildlife manager for Hancock Timber Resource Group, also would participate.
"Just where is the local input?" Mr Amis asked. "It appears that Hancock and AKF are not properly assessing community knowledge about this issue. What existing data are they drawing on? Surely to determine whether koala habitat is being harmed, field work would have to take place in every forest coupe that Hancock plan to log. It also appears that radio tracking will not be used in the study either, making it impossible to determine koala range. The study will only work from random samples. As far as we can tell the methodology of the study will not be made public either. Without knowing the methodology and by not having the process open to independent scientific peer review, it would appear that both the AKF and Hancock are attempting to stifle public comment on the process. The whole process sounds rather suspect to our organisation. It appears to be a smokescreen".
"We have serious concerns that by not properly accessing community knowledge about the Strzelecki koala, both HVP and Hancock could be seen to be attempting to pull the wool over people's eyes. Friends of the Earth's concerns are that local knowledge is not being requested because Hancock are solely interested in getting access to the Mountain Ash trees in the higher elevations. Local residents have for years pointed out that Strzelecki Koalas are found in Mountain Ash habitat. We fear that the 'study' could be interpreted as meaning that singular stands of Mountain Ash will not be regarded as important habitat, thereby allowing HVP to log these few remaining areas". Mr Amis said.
Mr Amis concluded by saying that "HVP have been saying that they want their forest holdings certified in Victoria by the Forest Stewardship Council. That process requires all parties including conservationists, indigenous people, workers and industry to reach agreement over forest management. We see the AKF/HVP agreement as working against the interests of certification in that HVP are setting up a knowledge hierarchy where they will consult with one group at the expense of other groups".
For further information on these issues, including details of Hancock's logging in the Strzelecki's over the past two years - check the website: www.forests.org.au/strzelecki
For further comments contact Anthony Amis on (03) 9419 8700
ORGANISATIONS
ANNOUNCE JOINT KOALA PROTECTION INITIATIVE: INTERNATIONAL ZOOLOGISTS
JOIN INDEPENDENT STUDY.
MELBOURNE OCTOBER 2, 2000 - Hancock Victorian Plantations (HVP) and the Australian Koala Foundation (AKF) announced a joint Memorandum of Understanding (MOU) and the beginning of field studies to learn more about koalas and their habitat on HVP's leasehold properties in the Strzelecki Ranges of Victoria.
In a joint announcment, Kevin White, chief executive officer of HVP, and Deborah Tabart, executive director of AKF, said the memorandum - which provides for an independent year-long review of koala population and habitat preferences - is expected to lead to a comprehensive forest management plan involving protection for the species in the Strzeleckis.
White and Tabart said the MOU provides a framework for obtaining scientifically credible data on koala populations, critical habitat and future habitat needs. The desired outcome is a management strategy to meet the long-term needs of the koalas in the region as well as the commercial interests of HVP's investors.
The MOU was signed by both parties earlier in the year after talks began last December. It is the first such agreement between the AKF and a timber operating company.
Field studies begin today led by AKF's head of conservation research, Mr John Callahan along with zookeepers from five major North American zoos: Toronto, San Francisco, Bergin, San Diego and Disney's Animal Kingdom. Dr Wayne Marion wildlife manager for Hancock Timber Resource Group, also will participate.
"The scientific community regards the Strzelecki koala population as making an important contribution to the national koala gene pool" Mr White said. "This MOU along with the field studies, will hopefully lead to a situation where critical koala habitat on HVP's holdings will be permanently protected."
Tabart said "This MOU and the final Koala Habitat Atlas that will be produced could lead the way to sustainable logging by all companies in the Strzelecki Ranges. The koalas in this region are critical to the future of Victorian koalas and we are delighted that HVP understands their scientific importance."
The Koala Habitat Atlas is a project that aims to rank, identify and map critical habitat in a given area. The project already has received a Computerworld Smithsonian Award of Innovative Use of Technology. "These maps will enable us to find the critical koala habitat on the property" said Tabart. "Until that is done, it is difficult to predict whether forest operations are affecting the koala population. We do acknowledge that HVP has effectively set aside large conservation areas in its policy not to log native forests. The maps will give certainty to HVP investors, the AKF and most importantly, the koalas" Tabart said.
Whilst HVP is owned jointly by US and Australian pension funds and infrastructure investors, the Melbourne-based company is overseen by the Hancock Timber Resource Group (HTRG), the world's leading timberland investment management organisation for institutional investors. HTRG is a wholly owned subsidiary of Boston-based John Hancock Financial Services, Inc. (NYSE:JHF)
AKF is a privately funded international organisation whose prime focus and aim is the long-term conservation and effective management of the wild koala in Australia. The organization has offices in Brisbane, New York, Washington and Tokyo.
For more information please contact:
Deborah Tabart. Executive Director, AKF dtabart@savethe
koala.com
Ann Sharp, General Manager, AKF (07) 3229 7233 (up to 29 Sept)
John Callaghan, Principal Ecologist, AKF who will be in the field (0419-778-601)
HIGH EFFECTIVE INBREEDING COEFFICIENTS CORRELATE WITH MORPHOLOGICAL
ABNORMALITIES IN POPULATIONS OF SOUTH AUSTRALIAN KOALAS (PHASCOLARCTOS
CINEREUS)
Animal Conservation (2001) 4. 211-219 2001. The Zoological Society
of
London.
Ayesha M. Seymour1. Margaret E. Montgomery, Brian H. Costello1, Greg
Johnsson2, Barbara St. John2, David Taggart3 and Bronwyn A. Houlden1.4
1School of Biological Sciences, University of New South Wales. Sydney
2052, Australia
2Department of Environment, Heritage and Aboriginal Affairs, Biodiversity
Branch, PO Box 1047, Adelaide 5001, Australia
3Department of Zoology, University of Melbourne, Parkville 3052, Australia
4Zoological Parks Board of New South Wales, PO Box 20, Mosman 2088,
Australia.
(Received 1 September 1999, revised version received 15 December 2000;
accepted 5 February 2001).
Abstract
Koalas have undergone a series of sequential founding events on islands
in south-eastern Australia in recent times. Populations in South Australia
at the Eyre Peninsula and Mt Lofty Ranges were founded in the 1960s
from a colony on Kangaroo Island. The Kangaroo Is. colony was derived
from animals introduced to French Island from mainland Victoria over
a century ago. In this study, we first use microsatellite markers to
quantify levels of genetic variation within the South Australian koala
populations and the relatively unperturbed Strzelecki Ranges population
from mainland Victoria. This analysis revealed low levels of allelic
diversity (1.7+- 0.2 to 2.7 +- 0.5) and heterozygosity (0.208 +- 0.088
to 0.340 +- 0.110) in the three South Australian koala populations relative
to the Strzelecki Ranges population, which has the highest level of
allelic diversity (4.7+- 1.1) and heterozygosity (0.476 +- 0.122) in
Victoria. Second, we measured the incidence of testicular aplasia, a
unilateral or bilateral failure in testicular development, in the Eyre
Peninsula and Kangaroo Is. populations, and in the ultimate founding
population at French Is. Testicular aplasia was present at a frequency
of 4.3% in French Is., 12.8% in Kangaroo Is. and 23.9% in the Eyre Peninsula,
but was undetectable in the non-bottlenecked Pilliga State Forest population
of New South Wales. The incidence of testicular aplasia correlated positively
with effective inbreeding coefficients derived from heterozygosity values
(0.13 +- 0.06 in the Pilliga State Forest, 0.57 +- 0.17 in French Is.,
0.63 +- 0.12 on Kangaroo Island and 0.77 +- 0.12 in the Eyre Peninsula),
which may indicate inbreeding depression. These findings are of concern
when evaluating the long-term conservation and viability of the South
Australian koala populations, which may benefit from genetic augmentation
in the future. Finally, unconfirmed reports suggested that animals from
other states in Australia were introduced into the Mt Lofty Ranges population.
Therefore we quantified differentiation between the three South Australian
populations and the Strzelecki Ranges and French Is, populations, based
on microsatellites and mtDNA d-loop region variation. R-statistics and
Goldstein's delta mu square distance revealed that differentiation at
nuclear loci between populations paralleled known recent population
history, except for the close relationship between Mt Lofty Ranges and
French Is. This suggested a recent contribution to the Mt Lofty Ranges
populations of animals derived from the French Is, translocation program.
Furthermore, mtDNA d-loop analysis found no evidence of contributions
to the gene pool from animals of New South Wales or Queensland stock,
implying that the population was derived exclusively from Victorian
stock.
INTRODUCTION
Establishing small viable populations on offshore islands is becoming
an increasingly common conservation strategy in Australia (Serena, 1995;
Abbott, 2000; Jamieson & Ryan, 2000). However island populations
generally have higher risks of extinction than mainland populations
(World Conservation Monitoring Centre, 1992). Furthermore, island populations
generally have lower levels of genetic variation (Frankham, 1997) and
higher levels of inbreeding than mainland populations (Frankham, 1998).
Inbreeding can lead to loss of fertility, and decreased reproductive
success and survivorship (known as inbreeding depression) in plants
and animals (Wright, 1977). Inbreeding depression has been well documented
under controlled conditions in captive and laboratory animals (Ralls
& Ballou, 1983; Ralls, Ballou & Templeton, 1988; Brock &
White, 1992: Latter & Mulley, 1995; Laikre et al., 1996).
Despite the fact that it is more difficult to study, inbreeding depression
has also been found in wild animals (Chen, 1993; Packer & Pusey,
1993; Jimenez et al., 1994: Vrijenhoek, 1994; Frankham, 1995; Herschel
& Paige, 1995). Furthermore, it has been demonstrated in island
populations of black-footed rock-wallabies (Eldridge et al., 1999),
song sparrows (Keller et al., 1994) and takahe (Jamieson & Ryan,
2000). Inbreeding depression has also been found in species which exist
as isolated populations on 'virtual islands' in small reserves (Wildt
et al., 1987; Roelke, Martenson & O'Brien, 1993; Madsen, Stille
& Shine, 1996; Laikre, Ryman & Lundh, 1997; Saccheri et al.,
1998). Inbreeding depression is particularly likely to affect the long-term
viability of wild populations, owing to selection in harsher environmental
conditions (Chen, 1993; Jimenez et al., 1994; Miller, 1994; Saccheri
et al., 1988). However, effects on population viability may not be obvious,
since inbreeding and extinction display a threshold effect, beginning
at intermediate levels of inbreeding (Frankham, 1995).
In addition to effects on reproductive success and/or survivorship,
inbreeding is associated with an incresaed incidence of morphological
abnormalities in inbred rainbow trout (Kincaid, 1976), and in cryptochidism
in the Florida panther (Roelke et al., 1993). Furthermore, there is
clear evidence of fluctuating asymmetry in inbred rock-wallabies (Eldridge
et al., 1999), although the relationship between fluctuating asymmetry
and genetic diversity within populations is weak and inconsistent overall
(Gilligan et al., 2000).
Nevertheless, inbreeding does not necessarily lead to inbreeding depression
(Gibbs & Grant, 1989), and some species are apparently able to survive
with high inbreeding levels (Keane, Creel & Waser, 1996). Furthermore,
a recent study has suggested that an isolated pocket gopher population
has persisted and evolved without genetic input from elsewhere for over
2000 years (Hadley et al., 1998). Consequently, Lehman (1998) has challenged
the model that genetic variation per se at neutral marker loci is the
primary consideration in predicting population persistence. This issue
is central to conservation biology, since genetic management of threatened
and endangered species increasingly relies on the provision of advice
based on neutral microsatellite markers (Taylor, Sherwin & Wayne,
1994; Pope, Sharp & Moritz, 1996; Brown et al., 1998; Eldridge et
al., 1999).
Koalas are an ideal model species with which to study the loss of genetic
variation and its consequences on islands, because translocation programs
have established a series of populations that have undergone sequential
population bottlenecks this century. These include introductions of
koalas to areas outside their former range at Kangaroo Island, Mt Lofty
Ranges and the Eyre Peninsula in South Australia (Robinson, 1978). The
ultimate source of animals for these introductions was French Island
in Victoria, which was founded in the 1880s with as few as two or three
individuals from South Gippsland, Victoria (Lewis, 1934; reviewed in
Houlden, England & Sherwin, 1996). The Kangaroo Is. population was
founded with 18 animals from French Is. in 1923-25 (Gosse, 1939; Martin
& Handasyde, 1990). In 1969, the Eyre Peninsula population was established
with six founders from Kangaroo Is. (Robinson, 1978; ANZECC, 1998).
Furthermore, six animals were translocated to the Mt Lofty Ranges from
Kangaroo Is. in 1965 (Robinson, 1978; ANZECC, 1998). However, unconfirmed
reports suggested that koalas procured from Queensland, New South Wales
and Victoria may also have contributed to the gene pool in the Mt Lofty
Ranges (Robinson, 1978; ANZECC, 1998).
Populations established on the Eyre Peninsula and Kangaroo Is. have
expanded rapidly to reach carrying capacity, and in the latter case
now number several thousand individuals. This situation may have resulted
in the perception that loss of genetic variation and fitness, which
could occur as a consequence or severe bottlenecks or of founding events
(Wright, 1931, 1969), does not ultimately pose a serious threat to these
koalas' long term survival. In this study we used microsatellite markers,
which have proved to be sensitive measures of genetic variation in the
koala (Houlden et al., 1996), to quantify levels of genetic variation
within the South Australian koala populations and the relatively unperturbed
Strzelecki Ranges population from Victoria. We also quantified differentiation
between these populations and French Is., using microsatellites and
mtDNA d-loop region variation (Houlden et al., 1999). Finally, we investigated
rates of physical abnormalities present in these highy inbred populations
relative to the unperturbed Pilliga State Forest population (Montgomery,
2001) which may indicate inbreeding depression is occurring in koalas.
MATERIALS AND METHODS
Genetic analysis was undertaken from blood samples obtained from the
South Australian populations at Kangaroo Is. (KI) (35 o 43'S, 137o19'E,
n=29), the Eyre Peninsula (EP) (34o50'S, 135o40'E, n=20) and Mt Lofty
Ranges (MLR) in South Australia (34o59'S, 135o40'E, n=32) during 1997-98.
In addition, blood samples were collected from the Strzelecki Ranges
(SZ) in Victoria around Hazelwood (38o16'S, 146o22'E, n=33) from 1996
to 1998. Levels of genetic variation at microsatellite loci in the French
Is. population in Victoria (n=43) and the Pilliga State Forest in New
South Wales (n=40) have been published previously (Houlden et al., 1996;
Montgomery, 2001).
Rates of testicular aplasia (vestigial or absent testicle) (McPhee
& Buckley, 1934) were obtained from male koalas in the Eyre Peninsula
(n=46) and the French Is. (n=46) populations during 1998-99, and from
the Pilliga State Forest population (n=24) in 1998-2000. Testicular
aplasia was assessed in males from Kangaroo Is. (n=1200 in total) during
1997-99, and these data include koalas undergoing sterilization as part
of the Koala Management Program (n=1177). Koalas were anaesthetized
with Isoflo (Abbott Australia), which was administered with oxygen by
a mask or by intubation. Testicular aplasia was assessed by external
physical examination, and/or gross examination of the testis following
hemicastration.
DNA extraction from whole blood was performed using a salt precipitation
method (Lahiri & Nurnberger, 1991). DNA extraction from blood clots
was performed using proteinase K and phenol/chloroform extraction (Campbell
et al., 1995). DNAamplification was performed using six koala-specific
microsatellites as described previously (Houlden et al., 1996), except
that locus 13 was amplified using Amplitaq gold (Perkin Elmer). Genetic
variation was measured as the mean number of alleles per locus (A),
number of monomorphic loci (frequency of the common allele P>- 0.95),
and observed (Ho) and expected (HE) levels of heterozygosity using BIOSYS
(Swofford & Selander, 1981) as described (Houlden et al., 1996).
Differences in A and HE between populations were assessed for significance
by a one-way analysis of variance (Sokal & Rohlf, 1995), followed
by a Tukey's multiple comparison test, using SPSS 6.1 for Windows.
The effective inbreeding coefficient (Fe) was calculated from microsatellite
data using the equation of Frankham (1998): Fe = 1 - HIS/Hm, where HIS
was the heterozygosity level of unperturbed Nowendoc koala population
in New South Wales (0.831+-0.0017) (Houlden et al., 1996), which is
part of the same phylogeographic clade as the South Australian populations
studied here (Houlden et al., 1999). The relationship between the incidence
of testicular aplasia and Fe was analyzed by carrying out quadratic
regression and testing for significance using SPSS 6.1 for Windows.
Genetic differentiation between popluations was calculated in a number
of ways. The extent of heterogeneity in microsatellite frequency distributions
between populations was calculated using GENEPOP version 3 (Raymond
& Rousett, 1995). F-statistics were calculated using BIOSYS (Swofford
& Selander, 1981). RST values (from averaging variance components)
and the significance of RST were estimated with 1000 permutations using
the RST Calc program (Goodman, 1997). Values for 95% confidence limits
of estimates of RST, were obtained from 1000 bootstraps. In addition,
the delta mu squared genetic distance measurement designed for analysis
of microsatellite loci (Goldstein et al., 1995) was computed for pairwise
comparisons of populations using the RST Calc program (Goodman, 1997).
A mtDNA haplotype unique to koalas of Victorian/South Australian origin
has been previously identified using Heteroduplex/Temperature Gradient
Gel Electrophoresis analysis (TGGE) (Houlden et al., 1999). MtDNA variation
was assessed in this 864bp fragment of the 5' region of the d-loop,
which was amplified using the primers 15996L and 16502H, as described
(Campbell et al., 1995; Houlden et al., 1999). TGGE, which is a powerful
procedure which enables up to 90% of single base pair substitutions
between low melt domains in a heteroduplex to be identified (Campbell
et al., 1995), was carried out as described (Houlden et al., 1999).
RESULTS
Levels of genetic variation at microsatellite loci
Genetic variation in the Strzelecki Ranges, Kangaroo Is., Eyre Peninsula
and Mt Lofty Ranges populations was quantified at 6 previously described
(CA)-repeat microsatellite loci (Houlden et al., 1996). Microsatellite
analysis revealed that only 3 of the 6 loci were polymorphic in all
of these populations (Table 1 and Appendix 1). Phc-1 was monomorphic
(frequency of the common allele >-0.95) in all four populations,
and Phc-4 was monomorphic in all three South Australian populations
(Table 1 and Appendix 1). A third locus (Phc-13) was also monomorphic
in the Eyre Peninsula population (Table 1 and Appendix 1). The fixation
of alleles evident in these populations may have occurred as a consequence
of bottlenecks and founding events due to random genetic drift (Nei,
Maruyama & Chakraborty, 1975; Fuerst & Maruyama, 1986).
Population sample sizes ranges from 20 to 43, so the possibility that
rare alleles were missed owing to limited sampling was considered. The
sample sizes exceeded those statistically required to detect polymorphism
(p>-0.95) at a diallelic locus in the Mt Lofty Ranges and Strzelecki
Ranges populations with 95% confidence (P<-0.005) (Sjogren &
Wyoni, 1994). The sample sizes of the Eyre Peninsula and Kangaroo Is.
populations did not meet this expectation, but the frequency of the
rarest alleles at a hypothetical diallelic locus that would be detected
with a P+>-0.95 in a sample of 20 and 25 individuals in these populations
was 0.070 and 0.057 respectively. Furthermore, the probability that
a rare allele of frequency 0.05 would be detected in these two populations
is very high (P+=0.87 and 0.92 respectively). in addition, given that
the Eyre Peninsula and Kangaroo Is. were founded ultimately from stock
from French Is., these populations are likely to be monomorphic at the
same loci.
As expected, allelic diversity was significantly higher in the relatively
unperturbed Strzelecki Ranges (A=4.7 +-1.1) compared to the Eyre Peninsula
(A=1.7+-0.2) and Kanagaroo Is. populations (A=2.0+-0.3) (P<0.05)
(Table 1). Levels of observed heterozygosity (Ho) and expected (HE)
heterozygosity were also compared (Table 1). Although HE in the Strzelecki
Ranges (HE=0.476 +-0.116) was more than twice that found in the Eyre
Peninsula population (HE+0.208+-0.088) Table 1, neither HE nor Ho was
significantly different between populations (P>0.05).
Table 1. Genetic variation and incidence of testicular aplasia in four
koala populations
Population (sample size) Allelic diversity %polymorphic Mean heterozygosity
loci Observed Expected
Eyre Peninsula (20.0+-0.0) 1.7+-0.02 50 0.217+-0.091 0.208+-0.088
Kangaroo Is. (25.0+-1.8) 2.0+-0.3 66.7 0.350+-0.127 0.310+-0.086
Mt Lofty Ranges (31.8+-0.2) 2.7+-0.5 66.7 0.321+-0.101 0.340+-0.110
Strzelecki Ranges (32.2+-3.2) 4.7+-1.1 83.3 0.370+-0.112 0.476+-0.122
The observed and expected genotype proportions at each microsatellite
locus were tested for deviation from Hardy-Weinberg expectations in
each population. There was no significant departure from Hardy-Weinberg
equilibrium at any locus in either of the Strzelecki Ranges, Eyre Peninsula
or Mt Lofty Ranges populations. However, a significant heterozygous
excess at Phc-1 (P=0.001) and a heterozygous excess at Phc -11 (P=0.001)in
the Kanagaroo Is. population were observed. Deviations from Hardy-Weinberg
equilibrium were more than would be expected owing to chance alone,
and may indicate non-random mating due to sampling across demes in disjunct
localities throughout this large island.
Effective inbreeding coefficients and morphological abnormalities
Bottleneck theory predicts that loss of genetic variation associated
with inbreeding may lead to a loss of fitness. Effective inbreeding
coefficients (Fe) calculated from heterozygosity levels (Frankham, 1998)
were highest in the three South Australian populations at Eyre Peninsula
(Fe=0.75+-0.12), Kangaroo Is. (Fe=0.63+-0.12) and Mt Lofty Ranges (Fe=0.59+-0.15)
(Table 2). However, Fe was also high in the Victorian populations from
the Strzelecki Ranges (Fe=0.43+-0.16) and French Is. (Fe=0.57+-0.17)
data from Houlden et al., 1996), relative to the unperturbed Pilliga
State Forest population in New South Wales (Fe = 0.13 +- 0.06) (data
from Montgomery, 2001) (Table 2).
Table 2 Inbreeding coefficients and incidence of testicular aplasia
in koala populations
Population Effective inbreeding coefficient Incidence of testicular
aplasia (%) (n)
Eyre Peninsula 0.75+-0.12 23.9% (11/46)
Kangaroo Island 0.63+-0.12 12.9% (154/1200)
Mt Lofty Ranges 0.59+-0.15 nd
French Island (a) 0.57+-0.17 4.3% (2/46)
Strzelecki Ranges 0.43+-0.16 nd
Pilliga (b) 0.13+-0.06 0% (0/24)
(a) Data from Houlden et al., 1996
(b) Data from Montgomery, 2001.
The incidence of testicular abnormalities was significantly correlated
with effective inbreeding coefficients in koala populations (R2=0.97,
F=28.8, P=0.03) (Table 2, Fig.1). The highest rate of unilateral testicular
aplasia was observed in animals from the Eyre Peninsula population (23.9%,
n=46). Testicular aplasia was also found in animals from Kangaroo Is.,
where the left, right or both testes were affected with frequencies
of 4.5%, 7.5% and 0.9% respectively, totalling 12.9% (n=1200 males).
The French Is. population had a lower incidence of testicular aplasia
(4.3%, n=46 males). Although there is no date available for the Mt Lofty
Ranges and Strzelecki Ranges populations, the incidence of testicular
aplasia was assessed in the Pilliga State Forest of New South Wales,
where it was not detected in a survey of 24 male koalas.
Population differentiation
Genetic differentiation between the three South Australian koala populations
was first assessed from the frequencies of shared microsatellite alleles
(Appendix 1). Allele frequencies differed significantly at 3 loci examined:
Phc-25 (P<-0.01), Phc-11 (P<-0.001) and Phc-13 (P<-0.001).
A comparison of allele frequency distributions between Kangaroo Is.
and the Eyre Peninsula only showed a significant difference at Phc-13
(P<-0.001), owing to fixation of the common allele in the Eyre Peninsula
(Appendix 1).
However, allele frequency distributions between Kangaroo Is. and the
Mt Lofty Ranges showed significant differences at Phc-25 (P=0.02), Phc-11
(P<-0.001) and Phc-13 (P <-0.001) owing to the presence of private
and rare alleles in the Mt Lofty Ranges (Appendix 1). These private
alleles may have originated from the inadvertent release of koalas originating
in other states to the area. To address this issue, the Eyre Peninsula
(n=20), Kangaroo Is. (n=34) and Mt Lofty Ranges (n=32) populations were
screened for the presence of a mtDNA d-loop haplotype unique to animals
of Victorian/South Australian origin (Houlden et al., 1999). Variation
in a 864bp region of mtDNA d-loop was characterized by outgroup heteroduplex/TGGE
analysis, which revealed that all individuals possessed this unique
haplotype (Hap18) decribed previously (Houlden et al., 1999) (data not
shown). The failure to find evidence of mtDNA haplotypes derived from
koalas originating from New South Wales or Queensland suggests that
the private microsatellite alleles present in the Mt Lofty Ranges were
derived from Victorian stock.
A moderate degree of differentiation between the three South Australian
populations, the founding population from French Is. and the Strzelecki
Ranges population was identified using F-statistics (FST=0.112) and
R-statistics (RST=0.0608, P=0.001. 95% confidence limits between 0.0431
and 0.1201). Pairwise comparisons of RST revealed that differentiation
between populations paralleled known recent population history (Table
3). The three South Australian populations were not differentiated:
RST values for the source population at Kangaroo Is. versus the recipient
Eyre Peninsula and Mt Lofty Ranges populations were not significant
(RST=-0.0067 and 0.0026 respectively) (Table 3), and neither was the
RST value for the Eyre Peninsula versus Mt Lofty Ranges (RST=-0.0237)
(Table 3). The Eyre Peninsula and Kangaroo Is. were both significantly
divergent from French Is. (RST = 0.1166 and 0.0685 respectively) (Table
3), which was the ultimate source of founding stock for Kangaroo Is.,
earlier this century.
In contrast, French Is. was not significantly differentiated from either
the Mt Lofty Ranges (RST=0.0166) or the Strzelecki Ranges (RST=0.0095)
(Table 3). The latter population is geographically adjacent to populations
receiving immigrants as part of the French Is. translocation program.
The relationship between French Is and Mt Lofty Ranges of animals of
Victorian stock, derived from the French Is. translocation program.
Finally, the Strzelecki Ranges population was divergent from the geographically
distant Eyre Peninsula, Kangaroo Is. and Mt Lofty Ranges populations
(RST=0.2028, 0.1421 and 0.0787 respectively) (Table 3). This was expected,
since the Strzelecki Ranges population shares no direct contemporary
history with the South Australian populations.
Finally, differentiation between the three South Australian populations,
the founding population from French Is. and the Strzelecki Ranges population
was summarized using Goldstein's delta mu squared genetic distance (Goldstein
et al., 1995) (Table 3). Goldstein's delta mu squared genetic distance
revealed identical trends to RST, and ranged from 32.905 (between Strzelecki
Ranges and Eyre Peninsula) to 2.784 (between Eyre Peninsula and Kangaroo
Island) (Table 3). Again, the Strzelecki Ranges population was divergent
from all three South Australian populations, but relatively little differentiation
was demonstrated between the Eyre Peninsula, Kangaroo Is. and Mt Lofty
Ranges (Table 3).
Table 3. Matrix of pairwise comparisons of RST (above diagonal) and
Goldstein's delta mu squared (below diagonal) in five koala populations.
Population Eyre Peninsula Kangaroo Is. Mt Lofty Ranges French Is. Strzelecki
Ranges
Eyre Peninsula - -0.0067 0.0237 0.1166* 0.2028*
Kangaroo Is. 2.784 - 0.0026 0.0685* 0.1421*
Mt Lofty Ranges 6.547 3.375 - 0.0166 0.0787*
French Island 19.579 12.354 3.710 - 0.0095
Strzelecki Ranges 32.906 23.076 11.133 2.149 -
DISCUSSION
The conservation of threatened and rare mammal species through translocation
to islands is currently being advocated in Australia (Abbott, 2000).
The program which introduced koalas to French Is. and subsequently reintroduced
them back to the Victorian mainland has successfully re-established
the species throughout most of its former range in south-eastern Australia.
From a demographic perspective, this program has achieved its goals,
and koalas are now common in this region of Australia. Koalas from French
Is. were also introduced to areas outside their former range at Kangaroo
Is., Mt Lofty Ranges and the Eyre Peninsula. Subsequently, as predicted
by Wright (1931, 1977), a reduction in genetic variation has occurred
in these populations as a consequence of this founding history, which
our study demonstrates is significantly correlated with testicular abnormalities.
We revealed that levels of allelic diversity are significantly lower
in the Kangaroo Is. and Eyre Peninsula populations relative to the Strzelecki
population in Victoria, as expected from their population history. Overall,
the level of allelic diversity present in the South Australian populations
(A=2.1) was more than fivefold lower than values reported for relatively
unperturbed north-eastern populations from Queensland and New South
Wales (A=11.5) (Houlden et al., 1996).
As a group, the South Australian populations possessed less than one-thrid
of the heterozygosity (HE=0.286) found in the unperturbed north-eastern
Australian populations (HE=0.85) (Houlden et al., 1996). Levels of genetic
variation in South Australian koala populations are also much lower
compared to other marsupials including the bridled nailtail wallaby
(HE=0.83) (Moritz et al., 1996), bilby (HE=0.75) (Moritz et al., 1997)
and the yellow-footed rock wallaby (HE=0.67) (Pope et al., 1996). In
fact, heterozygosity levels are similar to those found in the highly
endangered northern hairy-nosed wombat (HE=0.27) (Taylor et al., 1994).
Effective inbreeding coefficients (Fe) calculated for the South Australian
koala populations are high, and are similar to those documented for
a number of wild and domestic non-endemic island populations in other
species (reviewed in Frankham, 1998). This is a cause for concern, since
the loss of genetic variation and inbreeding have been associated with
lowered fecundity, high infant mortality, lowered reproductive rates
and increased susceptibility to disease (O'Brien et al., 1985; Allendorf
& Leary, 1986: O'Brien & Evermann, 1988; Ralls et al., 1988;
Packer et al., 1991). Although data for marsupials are limited, a highly
inbred (Fe=0.91) black-footed rock-wallaby population suffers from reduced
female fecunity, skewed sex ratio and increased levels of fluctuating
asymmetry (Eldridge et al., 1999). Given this large body of evidence,
reports that some species are able to survive with high levels of inbreeding
(Gibbs & Grant, 1989: Keane, Creel & Waser, 1996) should be
treated cautiously, given the threshold relationship between inbreeding
and extinction (Frankham, 1998).
Although inbreeding effects have been shown to be severe in nature
(Jiminez et al., 1994; Keller et al., 1994), species have different
genetic loads (Ralls et al., 1988). Although predicting the impact of
inbreeding on koalas is difficult, evidence for inbreeding depression
in koalas has been detected in captivity. A male-biased sex ratio was
found in a Queensland colony (Worthington-Wirner et al., 1993), and
reduction in adult survivorship has also been reported for inbred captive
Victorian koalas (Sherwin et al., 2000). These findings argue against
the suggestion that koalas are naturally adapted to inbreeding (Worthington-Wilmer
et al., 1993).
This study is the first reported example of testicular aplasia in a
marsupial. Low levels of genetic variation, decreased reproductive potential,
and exponentionally increasing rates of testicular abnormalities described
as cryptochidism have been documented for the endangered Florida panther
(Roelke et al., 1993). Cryptochidism has also been documented in a number
of domestic species, where it is believed to be autosomal, recessive,
multigene trait (McPhee & Buckley, 1934; Claxton & Yeates, 1972:
Rothschild, Christian & Blanchard, 1988). Studies now underway will
determine whether testicular abnormalities in koalas are inherited,
and how unilateral abnormalities impact on reproductive fitness in males.
In Victoria and South Australia, koalas are considered to be secure,
based on population numbers. However, low levels of genetic variation
could have a significant impact on long-term viability of these populations,
given that genetic diversity is required for adaptation to changing
environments in the long term (Allendorf & Leary, 1986). Inbreeding
increases the probability of extinction of a population above inbreeding
coefficients of approximately 0.4 (Frankham, 1995), which are exceeded
by all south-eastern Australian koala populations studied to date (see
also Houlden et al., 1996). Furthermore, it has been suggested that
between 80% and 95% of deliberately inbred lines go extinct after inbreeding
coefficients exceed 0.80 (Frankel & Soule, 1981), which the Eyre
Peninsula population is approaching (Fe=0.75).
Increasing the level of genetic variation within the South Australian
populations is a management option that should be considered over the
long term. Genetic augmentation of koala populations in South Australia
could be considered once population size has been reduced sufficiently
to alleviate current problems with over-browsing and habitat damage.
This option is probably realistic for Kangaroo Is., where sterlization
of koalas is currently being undertaken. Augmentation could be accomplished
by the introduction of individuals from more variable populations, such
as the Strzelecki Ranges. Translocation of koalas is still practiced
as a management tool to ameliorate overpopulation on islands in Victoria
and South Australia, and is an established procedure. However, translocation
of animals may compund management problems in populations currently
above carrying capacity, and has the potential risk of introducing chlamydial
disease (Martin & Handasyde, 1990).
It is clear that the long-term conservation of koalas in South Australia
is a complex task. Management recommendations currently relate principally
to habitat conservation. While it may be difficult to undertake in the
short term, genetic issues should not be ignored in long term strategic
planning. It should also be recalled that the thousands of individual
koalas from the Kangaroo Is., Eyre Peninsula and Mt Lofty Ranges populations
were ultimately derived from French Is. stock (Robinson, 1978; ANZECC,
1998), and thus comprise an over-represented lineage of the species.
Further expansion of this lineage is contrary to currently accepted
species management practices for conservation of biodiversity, which
advocate preferential breeding of descendants of under-represented founders
(Foose & Ballou, 1988), and should not be pursued on that basis.
The findings of high levels of inbreeding and testicular and other morphological
abnormalities in South Australian koala populations revealed by this
study reinforce this recommendation.
Finally, we recommend to managers conserving threatened or rare species
on islands, or undertaking reintroductions from islands to mainland
Australia, that genetic issues are addressed and levels of diversity
monitored throughout the life of the program. While demographic threats
are often the most pressing issues in species recovery, isolation of
small populations on islands will make them more vulnerable to extinction
in the long term (Frankham, 1998).
Animal Conservation (2001) 4. 211-219 2001. The Zoological Society
of
London.
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