Chapter 4
Other threats: disease, dogs and motor vehicles
4.1
As part of its inquiry the committee heard evidence that, aside from
habitat loss and degradation, Australia's koala population is under pressure
from threats such as disease, dogs and car strikes.
4.2
Chlamydial disease and an AIDS-like syndrome referred to as the koala
retrovirus (KoRV) are prevalent amongst koala populations. Both these diseases
are impacting on the general health of the koala population and may be limiting
the species' ability to recover from other environmental stressors such habitat
loss and extreme climatic events such as droughts or bushfires.[1]
4.3
The increasing urbanisation of koala habitat in areas of human
population growth is also bringing koalas in closer contact with domestic dogs
and motor vehicles. In addition, recent research conducted by the Invasive
Animals Cooperative Research Centre has highlighted wild dog predation as a
significant and previously under-recognised threat to koalas.
4.4
This chapter discusses each of these threats sequentially.
Disease
4.5
According to the National Koala Conservation and Management Strategy
2009–2014, the most well known diseases present in koala populations until
recently are associated with chlamydia infection.[2]
The recently discovered koala retrovirus is also having a significant impact on
koala populations.[3]
Chlamydia
4.6
Chlamydial infection is common amongst the broader koala population
however not all animals show clinical symptoms. The symptoms often include eye
infections (such as conjunctivitis), respiratory tract and reproductive tract
infections as well as urinary tract infections which can cause the condition
referred to as 'dirty tail' or 'wet bottom'.[4]
Reproductive tract infections in koalas often results in infertility in female
koalas.[5]
Chlamydia can be transmitted through mating and passed from an infected mother
to her joeys at birth.
Retrovirus
4.7
Retroviruses are the same class of virus that include HIV. They have a
unique lifecycle that allows them to integrate a copy of their own genome into
the genetic material of their host.[6]
In doing so they are able to hijack host cell processes to produce many more
virus particles, in effect turning the host cell into a virus factory.[7]
Whilst this process is designed to promote the production of virus particles it
may also switch on genes of the host cell, which in turn may cause cancer.
Conversely, the viral DNA may disrupt a host cell gene leading to the death of
the cell or altered cell function.[8]
4.8
Koalas with the retrovirus usually present with ulcers in the mouth and
generally poor body condition. According to Dr Jon Hanger, the koala veterinary
specialist credited with discovering the koala retrovirus,[9]
the disease is considered responsible for causing the following medical
conditions in koalas:
- leukaemia (a cancer of the blood forming cells);
- myelodysplasia (abnormalities in production of blood cells);
- immunodeficiency syndrome (an AIDS-like condition in koalas); and
- other cancers including lymphoma, osteochondroma and
mesothelioma.[10]
4.9
The koala retrovirus (KoRV) is also believed to affect the way that
koalas are able to respond to infections.[11]
For example, chlamydia should be a relatively minor infection in koalas however
death from the disease is now common as a result of the increasing prevalence
of the retrovirus.[12]
Dr Jon Hangar told the committee:
Koalas we think should not get so sick from chlamydia but
they do. One of the hypotheses about why they do is that the koala retrovirus
is affecting the way they respond to that infection so they get more severe
disease. They can potentially die from it when really they should not die from
those sorts of infections. Then there are a whole range of primary diseases
like leukaemias and cancers that might be directly caused by the virus rather
than secondarily associated with immune suppression. My gut feeling is that it
is a significant cause of premature death in koalas.[13]
4.10
In New South Wales and Queensland the koala retrovirus is transmitted
genetically by inheritance from parents to offspring making it endogenous in
koalas.[14]
Although this is a known mechanism of transmission, koala retrovirus may also
spread from koala to koala by close contact and from infected mothers to their
joeys via the milk, similar to other viruses.[15]
It may also be possible for the virus to be vectored between koalas by insects.[16]
Prevalence of disease in the koala
population
Chlamydia
4.11
According to Dr Jon Hanger and Jo Loader, 'chlamydial infection in
koalas is common and affects most mainland and many island populations'.[17]
Prevalence of the disease varies between populations with severe disease more
common in northern koalas in Queensland than in southern koalas in Victoria and
South Australia. The TSSC stated that the South Australian and French Island
(Victoria) populations are thought to be chlamydia-free.[18]
4.12
However the committee was informed that as research on koalas is
conducted much more extensively in Queensland, evidence of the disease is much
more common in the state. Professor Peter Timms told the committee that chlamydial
infection rates of koalas in southern states could therefore be just as great
as those in northern Australia.[19]
4.13
The Australia Zoo Wildlife Warriors Worldwide (AZWWW) submitted results
of a trial conducted in conjunction with a number of research institutions into
the health of wild koalas in south-east Queensland. The study looked at koala
populations in Brendale, Narangba, East Coomera and Clagiraba. Ancillary tests
and health examinations were conducted on 113 koalas under general anaesthesia.[20]
Of the 113 wild koalas examined, 42 per cent were infected with chlamydia
and/or other diseases.[21]
According to the AZWWW:
The proportion of koalas with detectable reproductive disease
in each of these populations is remarkably high. This would unquestionably have
serious implications for the viability of these koala populations.[22]
4.14
The study also found that a large proportion of koalas surveyed had no
overt physical signs of illness and it was only by using thorough veterinary
investigative techniques that disease was detected.[23]
Picture
4.1—Diseased koalas (clockwise from top left: Anatomical Chlamydia Disease
Score (Eyes) Chronic kerato-conjunctivitis with active inflammation and
muco-purulent discharge; Chlamydial rhinitis characterised by nasal discharge; Veterinary
health examination of a female koala (with a joey) under general anaesthesia;
and Anatomical Chlamydia Disease Score (Urogenital tract) Cystic ovarian
bursitis - overall this koala was in good health and body condition)
Source: Australian Zoo Wildlife
Warriors Worldwide, Submission 22, Attachment A, pp 75, 102 and 115.
Reproduced with the permission of Ms Jo Loader, Research Scientist, Endeavour
Veterinary Ecology.
4.15
The committee also received data from the Port Stephens Comprehensive
Koala Plan of Management Steering Committee concerning rates of diseased
koalas. A study of over 500 koalas admitted to two koala care organisations and
three veterinarian clinics in Port Stephens between 2005 and 2008 showed that
approximately 10 per cent were diseased.[24]
Of those koalas that were diseased, approximately 85 per cent showed signs of
chlamydia. The Steering Committee's data also indicated that instances of
chlamydia have increased from 13 per cent in 2005 to 25 per cent in 2008.[25]
4.16
The Friends of the Koala also highlighted the high occurrence of disease
amongst koalas on the north coast of New South Wales. Approximately 54 per cent
of the 894 koalas admitted into care between 2007 and 2008 had diseases.[26]
Euthanasia was commonplace for admitted diseased koalas, accounting for over 80
per cent of disease mortalities.[27]
The Friends of the Koala stated that:
Disease is without doubt the most common cause of koalas
being admitted into care by Friends of the Koala and also the most common cause
of mortality. While it may be a fundamental element of Koala population
dynamics we see so much disease that in our view it is a significant
threatening process.[28]
Koala retrovirus
4.17
It is assumed that the koala retrovirus is spreading from the north of
Australia to the south.[29]
It is estimated that almost 100 per cent of the koala population in Queensland
and New South Wales are infected with the virus.[30]
In Victoria and South Australia incidence of the disease appears to be lower.[31]
4.18
However, the committee did hear evidence from the Koala Research Network
that the virus is currently sweeping through the koala population on Kangaroo
Island. According to Professor Paul Young the island:
...went from a situation in 2004 where we did a population
analysis and there were no infections on the island to a situation two years
later where there were 15 per cent, and three years after that it was upwards
of 36 per cent.[32]
4.19
It is not known how the koala retrovirus reached the island, however it
is speculated that it may have been vectored between individuals or arrived
from an infected animal that was translocated to Kangaroo Island.[33]
4.20
It is uncertain how long the koala population has been infected by the
virus. Dr Jon Hanger told the committee that the way the virus is acting in the
population indicates that it is a fairly recent incursion. However he noted
that it is difficult to estimate when the disease entered the population due to
the difficulties in dating such viruses with molecular clocks.[34]
4.21
The University of Queensland Koala Ecology Group suggested that koalas
have long been infected with koala retrovirus, citing the presence of the virus
on North Stradbroke Island which has been separated from the mainland for
thousands of years.[35]
The effect of disease on the koala
population
4.22
The extent of the impact of disease on the koala population is debated
by koala scientists. It is considered by some experts that diseases,
particularly the koala retrovirus, have been present in koalas for the
thousands of years and are not population limiting. Others speculate that the
disease is a recent incursion on the koala population and has the capacity to
have a significant impact on koala numbers.[36]
4.23
Professor Frank Carrick and Dr Alistair Melzer both submitted to the
committee that they believe there is no evidence to suggest that the koala
population will become extinct from chlamydia or the koala retrovirus.[37]
Dr Melzer argued that:
There are a wide range of diseases and “ill health” that can
be found among wild koalas when examined intensively. I argue, however, that
this is the normal state of any wild population and such disease profiles may
well have an ecological role of keeping populations in check.[38]
4.24
To Dr Melzer, the influence of overt chlamydiosis in northern koala
populations seems to be associated with primary environmental stressors. The
consequence however may be 'to reduce the resilience of the populations and
lower the probability of future recovery'.[39]
4.25
Professor Carrick submitted that the evidence indicates that koalas have
co‑evolved with both chlamydia and retrovirus for at least a few million
years.[40]
Professor Carrick went on to point out that:
There is a difference between being infected and being sick.
Can these organisms lead to sickness and death in Koalas? In
the case of chlamydial disease, certainly but NOT inevitably. In the case of
KoRV probably yes, but situation is still being clarified (and more work needs
to be done).[41]
4.26
Conversely, the AZWWW submitted that diseases have the potential to wipe
out the koalas population:
It is our view that both KoRV and Chlamydia are highly
significant in both their potential impacts on individuals, and on populations.
We believe that, in respect of Queensland and NSW koala populations, both
should be considered critical threats to long-term viability. It is likely that
it is only a matter of time before the same can be said of the Victorian and
South Australian koala populations.[42]
4.27
According to the AZWWW the disease not only presents a threat to koalas
that may die of the disease, but population viability becomes threatened due to
the high level of infertility that may result from chlamydia.[43]
4.28
Dr Jon Hanger told the committee that:
...the koala declines that we are seeing, according to the
scientific evidence and also the anecdotal evidence that is before us, are far
more dramatic than can be explained by habitat loss alone. In other words, even
in areas of apparently good koala habitat that are not badly affected by
urbanisation pressures or other pressures, we are still seeing dramatic
declines of koalas.[44]
Vaccination and funding
4.29
The committee heard evidence from Professor Peter Timms of the Koala
Research Network that good progress is currently being made towards developing
a vaccination for chlamydial infections in koalas. Trials are currently being
conducted on animals at the Lone Pine Koala Sanctuary and Australia Zoo with
field trials expected to be conducted soon.[45]
4.30
It is anticipated that to deploy the vaccination through field trials,
wild koala populations that are under active management would be targeted for
the vaccine. Individual koalas in these populations would be caught and
injected. Koalas would need to be recaptured and vaccinated after the initial
injection to deliver the full course of the vaccination.[46]
4.31
In the longer term it is hoped that small capsules may be injected into
koalas that would release after 60 days or 120 days to eliminate the need to
recapture them. Professor Timms told the committee:
...I think we are in a situation now that we can probably
manage tens of thousands of koalas actively by using, potentially, a vaccine.[47]
4.32
Scepticism was raised over the possibility of administering a
vaccination to a significant number of koalas for it to be effective. Professor
Frank Carrick told the committee that:
It is difficult enough to deploy vaccines to people, where
they want to get vaccinated and they will queue up at a medical facility to get
vaccinated. To deploy this in a wild population is going to be a big ask. The
other thing is: would you really want to do it? You would lose the ability to
monitor which koalas are naturally infected and which have been successfully
vaccinated. Again, they are not closed populations. If you actually
successfully achieve vaccination, you are going to have to do it forever.[48]
4.33
The committee heard that whilst a vaccination for chlamydia is nearing
field trials, a vaccination for the koala retrovirus is further away. Dr Hanger
informed the committee that developing a vaccination for the koala retrovirus
is problematic as has been shown in developing vaccines for HIV and AIDS.[49]
However success has been made in developing a vaccine for feline leukaemia
virus giving cause for hope that something similar could be developed for
koalas.[50]
4.34
A recurring recommendation from submitters was for funding to be made
available for combating disease in koala populations.[51]
For example the Sunshine Coast Regional Council submitted that:
Significant funds need to be allocated to further understand
the health of koala populations within South East Queensland and in particular
the diseases they are susceptible to.[52]
4.35
Submitters compared the disease in the koala population to the plight of
the Tasmanian devil but without the associated funding. For example Dr Hanger and
Jo Loader argued that:
The koala retrovirus has the potential to be one of the most
significant factors in the severity and prevalence of serious disease in
koalas, and yet the funding allocated to better understanding it has been
pitiful. It is our opinion that this virus may be as devastating to koalas as
the Tasmanian devil facial tumour disease in devils or chytrid fungus disease
in frogs. Both have received orders of magnitude more funding than has research
on the koala retrovirus.[53]
4.36
It was estimated by Professor Timms that between $2 million and $5 million
in funding would be required to create a program to administer a vaccination
for chlamydia to koalas in Queensland.[54]
4.37
Dr Jon Hanger told the committee that for a vaccination for the koala
retrovirus to be researched, developed and distributed to infected animals in
Queensland and New South Wales, funding in the order of $20 million would be
required.[55]
4.38
The Koala Research Network submitted to the committee that a holistic
approach to koala population, conservation and disease research is needed. The
network stated:
Arguably the koala decline is much more complex and difficult
to address than the Tasmanian devil facial tumour disease, and hence the level
of funding should reflect that, but with a similar urgency.[56]
4.39
The Koala Research Network estimated that in order to address the
research priorities identified in the National Koala Conservation and
Management Strategy 2009–2014, including disease research and vaccination,
funding in the region of $36.5 million over a five year period is
required.[57]
4.40
The committee has also received correspondence from the Koala Research
Network, outlining the funding it is seeking ($120 000 for one year) for a
Research Liaison Officer.[58]
Committee comment
4.41
The committee notes the significant impact that disease, and in
particular chlamydia and the koala retrovirus, is having on the koala
population. The committee also notes that there is some disagreement amongst
koala researchers about the level of the threat posed by disease.
4.42
The committee accepts that the prevalence of serious disease-related
infections is increasing and that this is an indication of the generally poor
state of health of individual koalas and of large sections of the overall koala
population. In the committee's view the cumulative impact of disease and other
threats, such as habitat degradation, results in a less resilient koala
population and lowers the probability of future recovery.
4.43
The committee also notes the paucity of funding for koala disease
research. The committee supports the integrated research proposal developed by
the Koala Research Network which includes a research theme dedicated to koala
disease. Not only would this five year research project supply vital
information on the mitigation of disease impacts in the koala population, it
also would provide critical data on koala population numbers and trends as well
as establishing a national koala monitoring program. The committee notes the
estimated cost of the project of $36.5 million over five years, and believes
this should be a Budget priority for the government.
Recommendation 10
4.44 The committee recommends that the Australian Government fund research
into koala disease, including the viability of vaccination programs and the
effect of changes in leaf chemistry.[59]
4.45
The committee also supports the Koala Research Network's funding request
to engage a Research Liaison Officer.
Recommendation 11
4.46 The committee recommends that the Australian Government fund the Koala
Research Network's request for a Research Liaison Officer.
Predation by dogs
4.47
The committee received evidence that indicated that certain feral and
domestic animals, in particular dogs, are having a significant impact on the
koala population.
4.48
In the National Koala Conservation and Management Strategy 2009–2014,
it was noted that:
Dog attacks primarily occur mainly where koalas use habitat
in urban areas, on small rural holdings close to urban centres and in
semi-urban areas. They also occur in the wider landscape in areas such as
national parks, reserves and on a range of rural holdings.[60]
4.49
Submitters to the inquiry gave evidence of dog attacks on koalas in
urban areas in the south-east region of Queensland and northern New South
Wales.[61]
The committee heard that in areas of urban expansion, corridors of koala food
trees are becoming blocked by barriers such as fences and roads.[62]
The fragmentation of their natural habitat has meant that koalas have to search
across wide distances for food and are increasingly coming into contact with
domestic dogs as well as cars.[63]
Koalas are also tempted to use food trees in properties that contain domestic
dogs.[64]
4.50
According to the Queensland Department of Environment and Resource
Management, 1306 koalas were attacked by dogs in south-east Queensland between
1997 and 2009.[65]
As a result of these attacks 954 koalas were either killed or euthanased due to
their injuries.
Picture 4.2—Koala with left forepaw injury as a result of a
domestic dog attack
Source: Ms Jo Loader, Research
Scientist, Endeavour Veterinary Ecology. Reproduced with the permission of Ms
Jo Loader.
4.51
The committee also received evidence from the Friends of the Koala in
northern New South Wales indicating that approximately 5 per cent of the 894
animals admitted into their care between 2007 and 2010 were attacked by dogs.[66]
4.52
Submitters also highlighted that a significant number of dog attacks on
koalas may go unreported. The Friends of the Koala informed the committee that
many dog attacks occur at night and in bushland largely unfrequented by people.[67]
Koala Action Pine Rivers also submitted that perhaps only one in every two dog
attacks is reported.[68]
4.53
In its consideration for listing the koala as vulnerable under the EPBC
Act, the Threatened Species Scientific Committee (TSSC) noted that data on
mortality of koalas is often collected by koala care groups and 'demonstrates
that mortality from dogs and cars occurs wherever koala habitat is in proximity
to urban environments'.[69]
However, the TSSC noted that there are difficulties associated with the use of
the data for several reasons including:
-
the area over which the data is collected is often not defined;
-
it is unclear what proportion of incidents go unreported;
- the size of the population from which the incidents are drawn are
often unknown; and
- there may be considerable overlap in the areas for which
different groups report.[70]
Local government response
4.54
The management of domestic dogs in Australian states is largely
undertaken by local government.
4.55
The committee heard evidence from a number of local government bodies
regarding measures that can be taken to prevent dog attacks on native wildlife
in urban areas.[71]
For example local governments may require:
- the compulsory 'denning' of dogs at night in areas of known koala
habitat;
- the creation of pet-free developments in key habitat areas; and
- the creation of local laws penalising owners of animals that kill
native wildlife.[72]
4.56
Redland City Council told the committee that there are some difficulties
associated with creating pet-free developments. According to Mayor Melva
Hobson, such developments are not always popular with developers or home
owners:
...we have looked at the possibility of inviting some areas
to be dog free. That, again, is a negotiation that we would have with the
developers. But as you say, there is not a lot of love in some areas, but in
other areas people are quite delighted not to have dogs because of associated
things with barking.[73]
4.57
Local laws that regulate domestic pets are also problematic for local
government to enact and enforce. The committee heard evidence concerning the
difficulties local government bodies have in enforcing the Queensland Animal
Management (Cats and Dogs) Act 2008 (the
Act). The Act is designed in
part to provide for the effective management of regulated dogs and
prohibits anyone from allowing or encouraging a dog to attack or cause fear to
people or other animals.[74]
Under the Act, a fine of up to $10 000 may be imposed on the owner of any
animal that causes the death of another animal.[75]
All animals are classed the same under the Act with no additional penalties
applied for the killing of native wildlife.
4.58
Sunshine Coast Regional Council informed the committee that it is
extremely problematic to prosecute animal owners under the Act. According to Dr
Stephen Skull, the Manager of the Council's Environment Policy Branch,
photographic or video evidence is essentially required to prove a domestic
animal committed an offence.[76]
4.59
The Threatened Species Scientific Committee also noted that despite
growing awareness of the problems of dog attack and the attempts to address
them, 'there is little evidence that such management responses have been
effective thus far'.[77]
Wild dogs
4.60
The committee also heard evidence about the possible impact of wild dogs
on the koala population. The Invasive Animals Cooperative Research Centre
(Invasive Animals CRC) informed the committee that whilst the economic impact
of wild dogs on agriculture and industry is known, the impacts on biodiversity
are often overlooked.[78]
According to Mr Greg Mifsud, National Wild Dog Facilitator with Invasive
Animals CRC, until recently researchers have underestimated the impacts of wild
dogs on the koala populations.[79]
4.61
Most state regulations consider that any dog not under the control of a
human to be a wild dog, including: dingos, dingo hybrids, feral domestic dogs
and roaming domestic dogs that are causing impact.[80]
4.62
Wild dogs populate rural areas, national parks, peri-urban and
semi-urban environments around the country. The Invasive Animals CRC estimate
that from anecdotal evidence of livestock attacks around the country, the
distribution and densities of wild dogs are increasing nationally.[81]
This is in part due to the success of wild dogs at adapting to modified
environments.
4.63
Wild dogs also prefer habitat that is favoured by koalas such as
established timber forests and vegetated areas around water courses.[82]
They use the cover of the forests to hide and are fond of soft ground to
protect their feet. Wild dogs will use the easiest route to travel from point
to point, including fire trials and dry creek beds.[83]
4.64
The committee heard evidence from the Invasive Animals CRC of the
increasingly shared habitat of koalas and wild dogs. In August 2009, the
Australian Koala Foundation and the University of Queensland conducted a koala
survey in the Charleville-area of south-west Queensland. The survey failed to
yield a sighting of a single koala in an area where they were once commonly
observed. During the same period, the Murweh Shire Council Wild Dog Committee
initiated a large scale wild dog control programme across the shire, including
areas previously surveyed for koalas. The programme resulted in the trapping of
1400 wild dogs in the Charleville area.[84]
4.65
The committee received advice from the Invasive Animals CRC that several
studies conducted across Eastern Australia have already identified the impacts
of wild dog predation on koala populations. These studies were said to have
demonstrated:
...the potential to cause local extinctions within fragmented
landscapes and to prevent populations from re-establishing and reaching natural
densities following catastrophes such as fire and drought.[85]
4.66
The Invasive Animals CRC also informed the committee of wild dog
populations that exist in bushland in south-east Queensland and on the
outskirts of suburbs in Brisbane, the Gold Coast and the Sunshine Coast. These
animals often go unnoticed and are mistaken by residents as domestic dogs
without collars.[86]
The Invasive Animals CRC therefore raised the possibility that wild dog attacks
on koalas in south-east Queensland are incorrectly attributed to domestic dog
attacks.[87]
4.67
Wild dog presence in high densities may also be 'modifying koala
behaviour and impacting on the health of individuals by limiting their movement
on the ground between habitat trees'.[88]
As a result, wild dogs may also be having an impact on koala populations
through starvation. It was suggested by the Invasive Animals CRC that the
presence of wild dogs in the habitat preferred by koalas has forced koalas to
remain in trees when otherwise they would have come to the ground.[89]
To escape from heat and to move to new food trees, koalas periodically come to
the ground. The high densities of wild dogs may therefore be forcing koalas to
remain in trees to avoid the predators, resulting in starvation.
4.68
Management of wild dogs currently involves a number of different methods
depending upon the situation and location.[90]
Baiting, trapping, fencing and shooting are all options used to control the
population.
4.69
In response to a question on notice, the Invasive Animals CRC informed
the committee of the potential for a research project to investigate the
impacts of wild dogs on koalas. This would initially involve a mapping exercise
to overlay the current extent of koala habitat with information on wild dog
distribution and activity across Eastern Australia. For a modest outlay of
around $55 000, this mapping exercise would provide the basis for prioritisation
of areas requiring immediate management of wild dogs.
4.70
The project's second stage would involve the implementation of intensive
wild dog control in the priority areas identified in Stage 1. Professional wild
dog controllers would be employed at a cost of around $120 000 per local
government area.[91]
4.71
Given that wild dogs conservatively cost the Australian agricultural
industry $48 million, the project could be expected to provide broader financial
gains through increased production from the grazing industry in eastern Australia
and a major benefit to rural communities.[92]
Feral cats
4.72
Feral cats were not considered to be a direct threat to koalas as they
are a 'critical weight specialist'.[93]
Feral cats prey on mammalian species between approximately 10 grams and 500
grams with a rabbit being at the upper-end of the prey that they could
physically take. The committee heard that apart from preying on juveniles, cats
would not pose a direct threat to koalas.[94]
Foxes
4.73
Dr Melzer drew the committee's attention to two anecdotal accounts of
predation by foxes on koalas.[95]
Committee comment
4.74
The committee notes the significant impact domestic and wild dog
predation has on koala populations. The committee also notes the various
state-government koala protection measures which are included in the National
Koala Conservation and Management Strategy. However, the committee believes
that more needs to be done to combat the threat posed by dog attacks.
4.75
Firstly, the committee encourages state governments and local councils
in priority koala areas to implement dog predation mitigation options.
4.76
The committee also support the Invasive Animals CRC's proposal to assist
koala conservation through wild dog control.
Recommendation 12
4.77 The committee recommends that the Australia Government consider further
wild dog control options in priority koala areas.
Motor vehicles
4.78
The high incidence of koalas being killed by road vehicles was raised as
a significant threat to their survival. The Friends of the Koala submitted that
car strikes are the second most common cause of koalas being admitted into care
and the second most common cause of mortality.[96]
The Sunshine Coast Environment Council believes that there is little capacity
for resilience with car strikes and recovery options must be urgently
investigated.[97]
According to the Queensland Department of Environment and Resource Management,
there were 4553 reported motor vehicle strikes in south-east Queensland between
1997 and 2009, resulting in more than 3400 koala fatalities.[98]
Picture 4.3— Koala road fatality in East Coomera,
South-East Queensland
Source: Ms Jo Loader, Research
Scientist, Endeavour Veterinary Ecology. Reproduced with the permission of Ms
Jo Loader.
4.79
The increasing fragmentation of both the landscape and the home ranges
of koalas with road infrastructure has brought koalas into close contact with
vehicles.[99]
Roads also present an insurmountable physical barrier for koalas to cross
leaving them isolated in pockets of bushland.
4.80
The Koala Action Group Queensland gave an example of two major arterial
roads in the Redland area of south-east Queensland being upgraded to four lanes
in the last five years due to increases in traffic volume. According to the
group this is 'one of the main causes of catastrophic decline in koala numbers'
in the area.[100]
4.81
As part of its Koala Response Strategy the Queensland Government
has committed to the use of koala-friendly design for all new main road
construction and upgrades. It is also piloting the retrofitting of koala
crossings at mortality hotspots on existing main roads.[101]
4.82
Associated with the impact of motor vehicles and road infrastructure on
koalas is the prevalence of anthropogenic noise on koalas breeding. According
to the University of Queensland Koala Ecology Group car noise impacts on the
vocal communication of koalas is an emerging area of research into declining
koala urban-based populations.[102]
Proposed solutions
4.83
The committee heard evidence of a number of methods that have been used
to varying degrees of success in protecting koalas from car strikes.
4.84
Fauna crossings which create passages for koalas to move under or over
roads are used in some areas of koala habitat in south-east Queensland. Redland
City Council gave the example of two koala underpasses that were constructed
with the help of federal funding on roads in the Koala Coast area.[103]
Koala exclusion fencing has also been used along some major roads.
Picture 4.4—Koala infrastructure, Karuah Bypass,
Pacific Highway, New South Wales
Source: http://karuah.thiess.com.au/html/gallery_a.html.
4.85
Redland City Council told the committee of a trial of flashing LED signs
to warn drivers of koalas crossing. Whilst the results of the trial were
unclear it was suggested that the option be reinvestigated with the ability to
change speed limits during certain hours when koalas are known to be on the
move (for example at night).[104]
4.86
Other solutions that have been suggested include the lowering of speed
limits on roads located near or within koala habitats and the installation of
speed cameras in known koala areas.[105]
The Wildlife Preservation Society of Queensland submitted that koalas injured
in car accidents at a speed of 60 km/h or lower have a greater chance of
recovery for release in the wild.[106]
4.87
It was also recommended by submitters that koala friendly design be
incorporated at the planning stage of all new main roads and main road
upgrades.[107]
Committee comment
4.88
The committee notes the significant impact road trauma has on koala
populations and the various solutions proposed by submitters.
4.89
The committee is of the view that in priority koala areas, state
governments and local councils can actively contribute to better road planning,
infrastructure and regulation. In order to minimise the impact of motor
vehicles on koalas, the committee makes the following recommendations.
Recommendation 13
4.90 The committee recommends that local and state governments:
- introduce appropriate speed limits in priority koala areas; and
- that where appropriate, build or retrofit underpasses or overpasses
for major roads in priority koala areas as well as installing koala fencing
adjacent to major roads.
4.91
The committee also believes that the Commonwealth should use its road
and infrastructure funding to encourage koala protection measures such as land
bridge overpasses and underpasses, and koala exclusion fencing.
Recommendation 14
4.92 The committee recommends where the Australian Government provides
funding for roads or other infrastructure in or adjacent to koala habitat, it
be contingent on the provision of adequate koala protections.
4.93
The committee notes that of the four koala states, only Queensland has
committed to any activities related to motor vehicles under the National Koala
Conservation and Management Strategy, including ensuring all new state roads
and upgrades are koala-friendly. The committee would like to see this
initiative rolled out in priority koala areas across the eastern seaboard and expects
the Commonwealth to take a leading role in the development of these national
arrangements.
Recommendation 15
4.94 The committee recommends that the Australian Government work with the
states to develop new national guidelines to ensure that all new roads and
upgrades in or adjacent to koala habitat are koala-friendly.
Navigation: Previous Page | Contents | Next Page