Chapter 2
Koala population
2.1
It was widely recognised throughout this inquiry that Australia's koala
population is in decline.[1]
However the overall national picture is far from straightforward. There are remarkable
regional differences across the koala's range, with overabundance in certain
isolated island or localised populations, at the same time as serious documented
declines in populations in certain rural, peri-urban and urban areas.
2.2
This chapter explores the following main issues:
- The importance of koala population data;
- Counting methodologies;
- Historical estimates of Australia's koala population;
- Current estimates of Australia's koala population;
- Population diversity; and
- Problems with current estimates.
2.3
The chapter concludes with the committee's views on the way forward on
this important issue.
The importance of koala population data
2.4
The future conservation status and management of Australia's koalas is
dependent upon accurate estimates of koala populations. The Conservation
Council ACT Region submitted that:
Lack of consensus regarding the size and viability of
remaining populations and regarding the extent of and reasons for decline, or
even overabundance in some instances, hinders the conservation task.[2]
2.5
A similar argument was made by the Wildlife Preservation Society of
Queensland which submitted that:
It is essential that koala populations are known because if
you do not know what you are managing how do you know if your approach is
appropriate. Not only do you need to know the size, an understanding of the age
classes is essential for effective conservation and appropriate management.[3]
2.6
Industry bodies also submitted that scientific estimates of the number
of koalas are needed to provide the basis for government action:
The Property Council believes that any decisions made on the
future of the koala population must be based on this critical information.
Too much regulation has already been implemented on the basis
of anecdotal evidence.[4]
2.7
Native wildlife in Australia can be protected by legislation at both the
Commonwealth and state level.[5]
However, for a species to be given legislative protection, evidence of the rate
of population decline is necessary.
2.8
In each of the state and territory jurisdictions where koala populations
occur, legislation is in place to protect species that are vulnerable or
threatened.[6]
One way for species to be given protection under such legislation, is for
environment ministers or independent scientific committees to be convinced that
the species has undergone, or is likely to undergo, a demonstrable reduction in
population size.[7]
2.9
At the Commonwealth level, accurate estimates of population size may
assist a species to be 'listed' under the Environment Protection and Biodiversity
Conservation Act 1999 (the EPBC Act).[8]
According to the Commonwealth legislation, for a native species to be
considered to be in the critically endangered, endangered, or vulnerable
category it needs to meet one of five criteria. All of the criteria are
dependent in one way or another on population data. For example several
criteria require, amongst other things, data on the estimated total number of
mature individuals or the rate of population decline.[9]
The key EPBC Act conservation status criterion relevant to koalas (criterion
one) requires not only current population data, but also population data from three
generations past, which according to the Threatened Species Scientific
Committee (TSSC) is 20 years.[10]
2.10
In its letter to the minister on the listing of the koala under the EPBC
Act, the TSSC emphasised the importance of robust population data:
...the koala population has undergone a marked decline over
three generations, due to the combination of a range of actions. The [TSSC]
therefore considers the koala to be potentially eligible for listing as
vulnerable. However, better demographic data are needed to make this judgement
with confidence.[11]
2.11
Further information about the deficiencies in koala population data is
presented later in this chapter. The possible listing of the koala under the EPBC
Act is further considered in Chapter 5: The status of koalas under the law.
2.12
Estimates of koala population numbers are also valuable in helping local
governments to formulate and implement koala management policies.[12]
For example Redland City Council submitted to the inquiry that estimates of low
koala numbers and community concern prompted the council to develop and endorse
a koala conservation and management policy.[13]
Counting methodologies
2.13
Due to their natural tendency for dwelling high in the tree tops, koalas
are inherently difficult to find in the wild.[14]
Koalas are not territorial and the home ranges of individuals extensively
overlap.[15]
Koalas also tend to move little under most conditions, changing trees only a
few times each day.[16]
Therefore exact counts of koalas are usually conducted in relatively small and
discrete localities. Estimates of koala numbers in larger areas are typically
achieved by extrapolation using a number of different methodologies, some of
which are outlined below.
Absolute counts
2.14
Small areas with defined boundaries can be examined systematically with
line searchers to count all koalas. Each tree and shrub capable of supporting a
koala is examined and marked so as not to double count animals.
2.15
According to Dr Alistair Melzer, the critical assumption of this
methodology is that all animals are found and counted.[17]
The search area must also be surveyed in one day to avoid complicating the
count as animals move overnight. This limits the size of the area that can be
searched.
Mark-resight
2.16
Koalas in a search area are caught and tagged with coloured ear tags
before being released. After some period of time the habitat is surveyed and
koalas are sighted with the number of tagged and untagged animals recorded. In
its simplest form the proportion of re-sighted tagged animals to the total
number of animals tagged is assumed to be the same as the proportion of all
koalas sighted to the unknown total koala population, thus estimating the total
population.[18]
2.17
Depending on the time between tagging and surveying, account needs to be
taken of the death or emigration of tagged animals and the birth or immigration
of new animals.[19]
The method assumes that an even mixing of animals occurs across the extent of
the habitat. In theory this method can be used to estimate populations across
relatively large areas but is limited by resources, access and infrastructure.
Density from distance
2.18
Koalas are spotted during a systematic transect-based search of the
target habitat. When a koala is sighted on or at a distance from the search
route the perpendicular distance from the route to the koala is measured and
recorded. The density of koalas is estimated from an analysis of the distances
from the route to the koalas and the length of the route. It is assumed that animals
above the transect will be detected and that detection declines with distance
from the survey transect. The probability of detecting an animal with distance
from the transect can be calculated.
2.19
According to Dr Melzer, koalas are suited to this survey method as they
do not flee from the observer.[20]
However skilled observers are required and a reasonable number of sightings is
needed for meaningful estimations of density to be made. The method is suitable
for surveying moderately large areas, though it is likely to be less useful or
impractical in areas with low koala densities.[21]
Koala Habitat Atlas[22]
2.20
The Australian Koala Foundation (AKF) has sought to formulate a
repeatable methodology for calculating estimates of koala population size and
distribution across eastern Australia. By developing a repeatable methodology
the AKF hopes to produce 'baseline figures with which future population
estimates could be compared and monitored'.[23]
2.21
To this end the AKF has developed the Koala Habitat Atlas (KHA) for
improving identification and ranking of koala habitat throughout New South
Wales, Queensland and Victoria.[24]
2.22
The KHA mapping is based on the Native Vegetation Information System
(NVIS). The NVIS is a comprehensive database that provides information on the
extent and distribution of vegetation types across the Australian landscape
down to one square kilometre. The NVIS Version 1 that is used in the KHA
delineates 23 major vegetation groups around Australia. Five of the major
vegetation groups include tree species used by koalas: Eucalypt tall open
forests, Eucalypt open forests, Eucalypt woodlands, Eucalypt open woodlands and
Callitris forests and woodlands.[25]
These five vegetation groups are then classified as potential koala habitat.
2.23
Using data on average koala home range size collected by the AKF or
published in scientific papers, an estimate of koala abundance in potential
koala habitat is achieved. This information is then used to create a population
estimate.[26]
2.24
According to the AKF, their scientific staff and assistants have
compiled a database of 80 000 individually measured trees from 2000 field
sites across the natural range of the koala.[27]
The AKF also submitted that their database which is made available to all
researchers is unprecedented in size and is a resource that 'does not come
close to existing in the Government'.[28]
2.25
The AKF stated that the both the NSW and Victorian governments have
acknowledged the Koala Habitat Atlas.[29]
2.26
The AKF acknowledged the use of 'fairly broad-scale data' in developing
the KHA, because 'in some places in the country there is very little data'.[30]
Respected koala expert, Dr Melzer, who reviewed the methodology, supported the AKF's
broad method, stating that 'I am firmly of the view that the general approach
taken here [the AKF's koala population methodology] is the only way to assess
potential koala habitat on a continental basis.'[31]
2.27
Whilst commending the work of the AKF in compiling the Koala Habitat
Atlas, Dr Melzer submitted that the data need to be treated with caution:
In general terms this [the Koala Habitat Atlas] is to
identify discrete bioregional units, obtain available data on population
density within the units and then extrapolate to the area of the mapped koala
habitat within each unit. While there are many limitations to this approach it
remains the only effective approach to deriving such estimates. However the
results must be interpreted cautiously because the data behind the estimates is
uncertain.[32]
2.28
It has been argued that the mapping achieved through the NVIS does not
resolve riparian communities adequately and some acacia communities that have a
eucalypt component have been excluded.[33]
According to Dr Melzer, 'as a result the approach will underestimate the extent
of koala habitat – albeit expected to support low density populations'.[34]
2.29
Dr Melzer also submitted that the AKF's use of data from a range of
published and unpublished sources that use different methodologies also present
issues of comparability. The use of data sources from different time periods
fails to take into account changes to population size since the data was
published.[35]
2.30
In response to a question on notice, the TSSC described the KHA
methodology as 'complex' but noted that this may be necessarily so:
This is a complex approach, with many assumptions for each
step, and where the consequences of inaccuracies or flawed assumptions may be
magnified in subsequent steps of the calculations. Again, to be fair, any
attempt at national population estimate for koalas may necessarily be complex
and require a series of potentially flawed and compounding assumptions.[36]
2.31
The AKF acknowledged these sorts of criticisms, noting that:
Whilst the methodology is open to criticism and will require
ongoing refinement, the AKF holds that it draws credibility by incorporating
the best available data from a wide range of sources. It provides a starting
point for future monitoring programs and a sound basis for refining population
estimates in collaboration with koala researches through the koala's remaining
geographic range.[37]
Geo-plotting
2.32
The committee received evidence from Ms Carolyn Beaton, a former
employee of the Australia Zoo Wildlife Hospital, who has created a website that
uses geographic information system (GIS) software to capture data of koala
sightings Australia-wide.[38]
Once registered with the website 'Koala Diaries', members of the public are
able to pinpoint the exact location of a koala sighting and then load this
information onto a central database and map. Since the creation of the website
in February 2010, the website has recorded 2087 sightings mainly from
South-East Queensland.[39]
2.33
This method of surveying koalas does not attempt to provide an estimate
of the national koala population. Individual koalas may be counted and plotted
several times under this methodology. However the aim of the website is to
utilise 'community knowledge and grassroots efforts' to better understand
koalas and their habitat in a single national database of koala sightings.[40]
Anecdotal evidence
2.34
Due to the difficulty, cost and logistics of conducting extensive counts
of koala numbers across more than one million square kilometres of the koalas
range, the committee received many anecdotal examples of the decline of
regional koala populations.[41]
The University of Queensland Koala Ecology Group stated that:
Koala population estimates have, in the past relied generally
on indirect methods of assessment, probably as a result of a lack of funding
limiting more comprehensive investigations.[42]
2.35
Often community members who had resided in the same location for a
number of years would quote a decline in hearing and seeing koalas. For
example, the Port Stephen Comprehensive Koala Plan of Management Steering
Committee submitted that:
Anecdotally, many long term residents of Port Stephens LGA
note that they would frequently see koalas on and around their properties 5–7
years ago and for the last two years koalas have rarely been sighted.[43]
2.36
The federal and state governments, research scientists, industry peak
bodies and the Australian Koala Foundation have all recognised the need to move
away from anecdotal estimates of koala populations.[44]
The Koala Research Network put to the committee that 'it is becoming
increasingly important to develop national standards and guidelines for
assessing...koala populations'.[45]
Air-borne tracking
2.37
Developments in technology may allow for air-borne tracking of koala
populations using infrared detectors. This technique may have benefits for
assessing koala populations over large areas and in habitats where density is
low.[46]
Community involvement
2.38
Many of the methods used for counting koalas and estimating population
numbers require many hours of fieldwork. The committee received a number of
submissions demonstrating the high degree of community interest and involvement
in undertaking this work.[47]
For example, Mr Chris Allen, who has a long history of involvement in koala
conservation in NSW, submitted that:
The level of voluntary involvement in agency-managed koala
surveys in the [southern NSW] region, in which more than 300 volunteers have
contributed to more than 800 days of fieldwork since 2007, is a testament to
the local community's commitment to the koalas...Survey teams have searched for
koala pellets through bush litter under more than 27 000 trees at more
than 900 grid sites, enabling assessment of koala distribution and abundance
over more than 35 000 ha of public and privately owned forests.[48]
Spot Assessment Technique – a
habitat mapping methodology
2.39
In contrast to the various counting techniques listed above, the Spot
Assessment Technique (SAT) was developed by the AKF in 1995 to determine
preferred tree species for koalas and to measure koala activity at a particular
site.[49]
2.40
The method involves assessing koala activity within the immediate area
surrounding a preferred koala food tree. A tree with a breast height diameter
of at least 100 millimetres is selected as the centre of the search plot. The
29 nearest trees with a similar minimum size are also included in the plot. A
systematic search for koala faecal pellets within a one metre radius of each
tree is then conducted. The search for faecal pellets continues for two
minutes, or until evidence of koalas is found.[50]
2.41
The activity level for a SAT plot is expressed as a percentage
equivalent of the number of surveyed trees that had evidence of koalas. For
example, a sample of 30 trees of which 15 showed evidence of koalas, the
resulting activity level would be determined as 50 per cent. Trees are then
able to be ranked as either a primary or secondary koala tree species or a supplementary
species.
2.42
According to the AKF, this method 'does not attempt to predict the
abundance or density of local koala populations'.[51]
Instead the SAT is:
...suitable for use in conjunction with land-use planning
activities and/or policies that require Koalas and their habitat to be
assessed, especially where identification of important areas for protection and
management is required.[52]
2.43
The Port Stephens Comprehensive Koala Plan of Management Steering
Committee criticised the SAT methodology as it indicates the presence of koalas
in the past but gives no indication of more recent activity.[53]
Koala scats are also difficult to age and are affected by rain and
decomposition.[54]
2.44
Koala researchers at the University of Queensland also raised concerns
about the SAT technique:
Recent data confirm that reliance on scat presence to
estimate tree species preference by koalas is not sufficient and in many cases
inaccurate (Ellis et al. 1998; Matthews et al. 2007) and unfortunately this
condemns some former research and predictions based on this principle. With the
greater sophistication and the use of appropriate methods such as diet
determination from faecal pellet analysis (Ellis et al. 1999), there is greater
confidence in habitat predictions from recent studies.[55]
2.45
The AKF submitted that whilst there has been some criticism of the SAT
methodology in the literature:
...given the desire to develop a rapid and cost effective
assessment methodology, and given that the results of SAT sampling generally
reflect the scientific consensus with regards to important koala habitats, we
feel that the SAT has merit.[56]
Preferred method
2.46
Many submitters stated that there is no best method for counting koala
populations. According to the Koala Research Network, 'the selection of the
method depends upon the questions being asked'.[57]
2.47
In a similar vein, the University of Queensland Koala Ecology Group
advised the committee that a combination of a number of methods is sometimes
the most accurate way of determining koala activity and populations size:
The indirect methods of estimating koala demographics – e.g.
using scat presence – are limited and unreliable, but they still provide
unequivocal evidence of koala presence. Newer survey methods that combine
scats, signs, sounds, visual confirmation (e.g. density from distance, airborne
heat detection) are being applied in a few long term reference sites across the
range of the koala.[58]
Historical estimates of Australia's koala population
2.48
It is estimated that the koala population prior to European settlement
was in the order of up to 10 million koalas.[59]
2.49
Not long after European settlement, koala numbers experienced a 'severe
decline'. According to the National Koala Conservation and Management
Strategy 2009–2014:
...clearing of habitat for agriculture in combination with
hunting, disease, fire and drought resulted in a severe population decline. By
the late 1930s they were considered extinct in South Australia and severe
declines had occurred in New South Wales, Victoria and Queensland. However, in
the late 1930s the fur trade ceased and state governments were introducing
protective measures...[60]
2.50
In his book Koalas: The little Australians we'd all hate to lose,
author Bill Phillips provides a detailed picture of the reasons for the decline
in the koala population following European settlement. Phillips states that '...during
the late nineteenth and early twentieth centuries the fur trade was responsible
for the death of several million koalas'.[61]
The poisoning and wire snaring of koalas devastated populations in South
Australia and Victoria and numbers in New South Wales were declining.[62]
2.51
Open hunting seasons on the koala were declared in Queensland in 1915,
1917 and 1919. Between 1 April and 30 September 1919 it was estimated that one
million koala skins were gathered.[63]
The last open season on koalas occurred in Queensland in 1927 with
approximately 584 000 koalas killed.[64]
2.52
According to Phillips, by the 1930s the state of the koala population
had been severely depleted such that:
...koalas were considered extinct in South Australia. There
were apparently only hundreds in New South Wales, thousands in Victoria, and
but ten thousand left in Queensland. While the accuracy of these estimates is
uncertain, they give an indication of the extent to which koalas were decimated
by the fur trade, disease and the clearing of forests for grazing and
cultivation.[65]
2.53
By the late 1930s the fur trade had ceased and state governments had
introduced legislation to provide limited protection to koalas. The first state
to introduce protective measures for koalas was Victoria in 1898. New South
Wales followed suit in 1903 with the Native Animals Protection Act. In South
Australia koalas became protected under the Animals Protection Act of 1912.[66]
2.54
Translocation programs were also used to re-establish koala colonies in
their former range. Animals from French Island and Phillip Island were used to
reintroduce populations to mainland Victoria and to a lesser extent South
Australia and the Australian Capital Territory.[67]
In South Australia, populations were also introduced at various stages during
the twentieth century to regions outside their original distribution: Kangaroo
Island in the 1920s, Adelaide Hills in the 1930s to 1970s and the Eyre
Peninsula in 1969.[68]
Historical variations
2.55
According to Dr Alistair Melzer, the uneven distribution of the national
koala population probably predates European settlement of the Australian
landscape and likely 'reflects the variability in plant communities and
associated nutrient and moisture regimes'.[69]
Historically, the koala has also been known to go through fluctuations in its
population. The TSSC gave the specific example of the Federation drought:
The koala recovered from the “Federation” drought across
central Queensland with sufficient speed and extent to be the subject of
intensive hunting and harvesting programs within 20–30 years of the drought’s cessation. In that
region, the Federation drought was at least comparable – if not more extreme – than the most recent drought...
In addition, there was substantial land clearance (by
extensive ring-barking),
hunting and poisoning immediately prior to and following the Federation drought.
It is therefore reasonable to assume that the koala has evolved to cope with
considerable climatic fluctuation, and should recover from this most recent
drought.[70]
2.56
However, Dr John Woinarski, who appeared before the committee as a
member of the TSSC, qualified the comparison between the Federation drought and
the most recent one, saying:
All such climatic fluctuations are different. Immediately
following the Federation drought there was a series of hunting episodes and
episodes of clearing in Queensland as well. It is likely that the cocktail of
factors this time around [increasing human population, land clearance, dog numbers]
may be more damaging, yes.[71]
2.57
A number of koala specialists, Professor Frank Carrick, Dr Alistair
Melzer, Dr Bill Ellis and Dr Sean Fitzgibbon, disputed the TSSC's
characterisation of the fluctuation of the koala population:
Whilst we concur [with the TSSC's evidence that] "Assessment
of the koala is neither straightforward nor simple", the assertion that "historically,
koala populations have shown very substantial fluctuations" neglects the
context that most of the observed "fluctuations" have been population
crashes associated with anthropogenically driven factors such as profligate
hunting and major disease epizootics [a disease that rapidly affects many
animals in a specific area at the same time] following hard on the heels of
major habitat destruction episodes...[72]
Early population surveys
2.58
The first national survey of the koala population was conducted from
1986 to 1987 by the National Parks and Wildlife Service. The National Koala
Survey did not set out to estimate the total number of koalas in the wild.
Rather it was designed to pin point locations where koalas warranted special
attention and to make an informed assessment of the conservation status of the
species on a national basis. The survey also collected information on the
preferred tree species of koalas, the dominant land use surrounding koala
habitat and the prevalence of disease in koalas.[73]
2.59
The National Koala Survey identified a total of 3145 sites where
koalas were either observed or thought to be present from tell-tale signs.[74]
The survey found that in the southern states, koalas had recovered from being
extinct in South Australia and near-extinct in Victoria to have flourishing
populations. The survey noted that the Kangaroo Island and French Island
populations had to be reduced through translocations and that 'the future of
koalas in southern Australia should be assured'.[75]
2.60
The survey identified that at the northern end of their range, koalas
are most abundant in the north-east corner of New South Wales and the
south-east corner of Queensland. The survey further noted that:
Both areas have rapidly expanding urban centres likely to
threaten habitat occupied by koalas. Unless land management practices takes
account of the habitat needs of koalas then local extinctions are inevitable.[76]
2.61
However for the species to survive in the long-term, the National
Koala Survey believed that the ability of koalas to repopulate in southern
Australia was evidence that koala populations 'can be managed, if necessary, to
augment dwindling populations or to recolonise areas which once supported
koalas'.[77]
Current estimates of Australia's koala population
National estimates
2.62
More recently, and despite the cessation of the koala fur trade,
Australia's koala population has 'undergone marked decline over three
generations'.[78]
These marked population declines are due to '...extensive habitat clearing and
fragmentation...disease, fire, drought and, more recently road deaths and
predation by dogs'.[79]
2.63
However despite widespread recognition of this worsening trend, the
'national population of the koala remains unclear...'[80]
According to their most recent advice to the Commonwealth environment minister
in 2010, the Threatened Species Scientific Committee stated that:
There is at present no published scientifically peer-reviewed
estimate of the total number of koalas in Australia and no definitive past
estimate within an appropriate timeframe to enable comparison.[81]
2.64
The National Koala Conservation and Management Strategy 2009–2014
notes that 'deriving reliable broad-scale koala population estimates remains
very difficult, so the national population of the koala remains unclear at this
stage'.[82]
The strategy notes that:
At a national level, it may be more realistic to estimate the
extent of habitat loss, fragmentation and modification and declines in
distribution as indicators of koala population declines rather than population per
se.[83]
2.65
Whilst the overall size of the national population appears to be
uncertain, it was widely stated by the majority of submitters that a
significant number of local and regional koala populations are declining.[84]
Drought, climatic extremes, loss of critical habitat, urbanisation and disease were
the main reasons quoted for the decline of koala numbers.[85]
2.66
Estimates of koala numbers have been gathered at specific locations
rather than across the nation as a whole and have used a variety of different
counting methods. Professor McAlpine, spokesperson for the Koala Research
Network, explained to the committee:
We do not know confidently the number of the overall koala
population in Australia. There are estimates of regional populations which we
know reasonably well, such as in parts of south-east Queensland and in western
Queensland, but overall I do not think we can confidently say what the numbers
are.[86]
2.67
Dr Bill Ellis explained to the committee the funding constraints faced
by researchers in estimating koala numbers:
The issue for us there is that we do not have the resources
to go out and count all of the koalas to get that sort of a number. All of our
studies are focused on particular areas...[87]
2.68
The most widely quoted estimate of the national koala population comes
from the AKF which estimates that there are between 43 515 and 84 615
koalas left in the wild.[88]
This range was broadly supported by Professor McAlpine, Spokesperson, Koala
Research Network, who stated:
There were once millions of koalas in Australia; now there
are probably no more than somewhere between 50,000 and 100,000, but we cannot
confidently say what those numbers are.[89]
2.69
As noted above, koala experts such as Dr Melzer submitted that the
AKF figure must be 'interpreted cautiously because the data behind the estimates
is uncertain.'[90]
2.70
While recognising and welcoming 'the attempt by the AKF to provide a
national, systematic and integrated approach to koala distributional modelling,
habitat preference and population assessment' the TSSC critiqued the AKF's
estimate saying that it was not based on peer reviewed science. Other concerns
raised by the TSSC were that the AKF's population estimate excludes all koalas
living is South Australia and, as discussed above, the methodology used to arrive
at the overall estimate.[91]
2.71
The AKF disputed the TSSC's claim that it did not rely on peer reviewed
science, submitting that:
In designing the methodological steps outlined below, AKF has
drawn on the collective research funded and managed by the AKF under the
auspices of many eminent koala scientists...in Australia.[92]
2.72
The Commonwealth government does not have a definite estimate of the
national koala population as an alternative to the AKF's estimate.[93]
In its advice to the Environment Minister the TSSC estimated the koala population
is 'greater than 200 000 individuals, with large populations in a number
of locations over four states.'[94]
However, other than some sporadic information about individual regional or
state populations, the TSSC provided the environment minister with very little
other information about the national koala population.
2.73
During the inquiry the committee sought further information from the
TSSC on this important issue. In response to questions on notice, the TSSC
indicated that:
Based on information presented at our commissioned workshop,
and published and unpublished information, we estimated the koala abundance
across all regions within their range, at the time of assessment and about 20
years previously. We concluded that the national koala population in 1990 was about
430,000, and in 2010 was about 300,000, a decline of about 31%. Based on more
recent information made available since our assessment, we estimate that a
plausible lower bound for the current national koala population is about
200,000 individuals. If regions in which the recent koala decline has been
driven primarily by drought are excluded from consideration, we estimate that
the decline over the rest of the range between 1990 and 2010 is about 16%.[95]
2.74
Several state governments have prepared state-wide population estimates
which are mentioned below.
2.75
The problems with current estimates of koala population numbers are
discussed in later in this chapter.
Queensland
2.76
The Threatened Species Scientific Committee noted that the current koala
population estimate in Queensland is 'problematic because of the koala’s wide
distribution to the north and west, and the lack of quantitative data in those
regions'. The TSSC judged that 'a reasonable estimate baseline (i.e. three
generations ago) figure for Queensland is approximately 300 000 koalas
with a plausible range of 180 000 to 550 000.'[96]
The TSSC did not provide a comparable figure for the current Queensland koala
population.
2.77
Since 1994 the Queensland state government has solely or jointly funded
research into estimating koala populations in the south-east of the state.
Surveys of koala populations have concentrated on the 'Koala Coast'[97]
and Pine Rivers areas. Data are not available for other significant populations
in the state, although the government believes that:
...in areas where land use is undergoing similar changes to
those occurring in the south-east, it is expected that koala population
dynamics will reflect those of the Koala Coast and Pine Rivers.[98]
2.78
The survey method used by the Queensland government includes habitat
stratification and intensive, systematic daytime searches of strip transect.
Geographic information system and remote sensing methodologies are also used to
assess the koala habitat component of the regional koala abundance estimates.
According to the government:
This approach allows for the identification and determination
of habitat areas for conservation based on where koalas actually occur rather
than identifying distributions of 'preferred' tree species or community
reports.[99]
2.79
The 2008 Queensland government survey of the Koala Coast koala
population estimated a 51 per cent decline in just three years and a 64 per
cent decline in ten years. Koala numbers have dropped from an estimate of 4611
koalas in 2005–2006 to just 2279 in 2008.[100]
An earlier survey in 1996–1999 estimated that there were 6246 koalas.[101]
2.80
A mapping and surveying project found that koala densities in the Pine
Rivers area had declined by 45 per cent in urban areas and by 15 per cent in
bushland sites.[102]
2.81
The Queensland government has committed $2.5 million in funding over
five years to expand the surveying and monitoring of koala populations across
the south‑east Queensland region.[103]
Monitoring of koala populations will also commence at Ipswich and Oakey.
2.82
The Threatened Species Scientific Committee made the following
assessment of the broader coastal south east Queensland region:
Koala populations in all SEQ coastal local government areas
(Sunshine Coast; Moreton Bay; Brisbane; Redland; Logan; and Ipswich) appear to
be following a similar downward trend to the Koala Coast and Pine Rivers
populations, as evidenced by a rapid increase in the numbers of sick, injured
and dead koalas, followed by a decline in koala numbers. Further north, koala
populations are less well known, often becoming known as a result of
development applications, but are generally considered to be at low density
(<0.2 koalas/ha) (White et al. 2005; Queensland EPA 2006).[104]
2.83
In other parts of the state, Dr Gregory Baxter of the Koala Research
Network informed the committee of an 80 per cent population decline in the
western mulga regions of Queensland:
...where we do have good estimates, like in the mulga lands
in western Queensland, we found that there was probably about 60,000 koalas
there in the mid-90s. We have just gone back and done the methodology in the
same way and there are probably only about 11,000 or 12,000 there now in the
same place. So everywhere we do have good data we find the same trend—it is
going down—so there is no reason to expect that in places where we do not have
the data there is something different going on. I think it is probably uniform
across the country.[105]
2.84
The committee also heard evidence from Dr Bill Ellis of a koala
population in Springsure where current surveys indicate that koala numbers have
declined by 95 per cent as compared to figures from the 1970s.[106]
New South Wales
2.85
Koalas were formerly widespread in New South Wales. According to the
former NSW Department of Environment, Climate Change and Water, remaining
populations are now concentrated on the central, mid-north and north coasts,
and in the north-west part of the state.[107]
Small and isolated populations also occur on the south and far south coasts,
and on the table lands of the Great Dividing Range.
2.86
Submitters such as Professor Carrick drew the committee's attention to a
series of documented local extinctions in NSW.[108]
The NSW Recovery Plan for the Koala also states that 'surveys in New
South Wales indicate that since 1949, populations of koalas have been lost from
many localities, particularly on the southern and western edges of their
distribution'.[109]
2.87
According to the NSW Recovery Plan for the Koala, 'there have
been no studies to estimate the size of the NSW koala population'.[110]
The population estimates that do exist for the state are described as being
'reasonable guesses and each can be justified'.[111]
2.88
It has been speculated that the koala population in New South Wales
could be between 1000 and 10 000 individuals however this figure is
disputed.[112]
The TSSC told the committee that their estimates for the koala population in
the state was 'at least 30 000 on public land'.[113]
The TSSC however did not reveal how they arrived at this figure.
2.89
The NSW Recovery Plan for the Koala recognises the value of
estimating the population size in NSW, however of a higher priority to the New
South Wales government is assessing changes in distribution and not numbers.[114]
Australian Capital Territory
2.90
The committee did not receive any specific evidence on the state of the
koala population in the ACT. According to the Threatened Species Scientific
Committee, the koala population of the ACT is likely to be very small.[115]
There have been at least six introductions from Victoria but no large or dense
populations have ever become established.
Victoria
2.91
According to the Victorian government, there is currently no accurate
estimate for the koala population in the state because the species is 'so
widespread, is difficult to accurately census, and occurs at widely variant
population densities'.[116]
2.92
The TSSC estimated that there are approximately 73 500 koalas in
Victoria and this population is largely 'a function of the translocation
program that has been operating for several decades.'[117]
2.93
In its submission the Victorian government noted the TSSC's estimate of
the state population. The government however stated that monitoring sites in
Victoria currently represent less than 1 per cent of the total koala habitat in
the state and that the TSSC figure:
...should not be taken out of context, as it was not meant to
be an estimate of the total number of Koalas in Victoria. Furthermore, it is
important to note that this estimate is certainly an under-estimate because
Koala populations occur in many areas away from those for which population
estimates were provided and many of these estimates were highly conservative.[118]
2.94
The Victorian government also submitted that at sites where koala
populations are overabundant, animals are being treated with contraception to
limit their numbers:
High-density, but small (<3000 individuals) populations on
French Island, Raymond Island and at Tower Hill State Game Reserve are now
being controlled by very intensive and expensive programs of mass contraception
using modified human contraception implants adapted for the Koala...[119]
2.95
Despite the overabundance of koalas in certain parts of Victoria (such
as French Island, Raymond Island, the Otway Ranges and Mt Eccles), the
government recognised that koalas are not 'flourishing everywhere in Victoria'.[120]
2.96
Koala populations with less than one animal per hectare exist across
central Victoria, the Strathbogie Plateau, the lower Glenelg River region, the
Bendigo-Ballarat region and in south Gippsland.[121]
2.97
The committee also received evidence of the rapidly declining koala
populations on the once over-populated Phillip Island. Phillip Island Nature
Parks submitted to the committee that the koala population on Phillip Island
has declined dramatically over the past three decades from 847 koalas in 1973
to 13 koalas in 2006.[122]
2.98
The committee also heard that a genetically diverse and significant
koala population resides in the Strzelecki Ranges:
The Strzelecki koala population has high levels of genetic
variability which have been detected by rare and unique genetic markers. These
animals are statistically differentiated from other Australian populations and
therefore constitute a separate management unit.[123]
2.99
No population surveys have been conducted on the Strzelecki population.[124]
South Australia
2.100
In South Australia, the natural range of the koala is restricted to the
south-east of the state. After being presumed extinct in the state in the
1920s, the koala population was reintroduced to its natural range with animals
from Victoria.[125]
Koalas were also translocated to areas outside of their natural range, namely
to: Kangaroo Island, Lower Eyre Peninsula, Adelaide's Mount Lofty Ranges and
the Riverland regions. Today in some areas they are increasing in number and
overabundant in other areas.[126]
For example the TSSC stated that the density of the koala population on
Kangaroo Island is putting 'unsustainable browsing pressure' on preferred tree
species.[127]
2.101
Koalas in South Australia are genetically very closely related –
generally descended from the very small numbers that were introduced onto
Kangaroo Island.[128]
2.102
The koala population on Kangaroo Island increased dramatically between
the 1920s and the 1990s. In 1997 the South Australian environment department
commenced a program to reduce the population on Kangaroo Island to sustainable
levels through surgical sterilisation and translocation.[129]
According to the government this was necessary because the highly selective
browsing of koalas represented a significant threat to Kangaroo Island's unique
vegetation, in particular the Manna Gum.[130]
Consistent with the National Koala Conservation and Management Strategy
2009–2014, the South Australian government has not considered culling as an
appropriate management option for koalas.[131]
2.103
In 2001 an island wide survey estimated a population of 27 000
koalas on Kangaroo Island.[132]
This survey was repeated in 2006 with a revised population of 16 000
koalas. The latest island wide survey took place in 2010 and preliminary
results indicate that the population continues to decrease.[133]
2.104
According to the South Australian government, the poor genetic quality
of koalas in South Australia and their overabundance has meant that:
Management is generally directed towards the maintenance of
the existing populations for their contribution to national rather than State
goals.[134]
Population diversity
2.105
A recurring theme throughout this inquiry was the varying levels of
genetic diversity of koalas from different regions. With a few notable
exceptions, for example the Strzelecki koala in Victoria's Gippsland region,
there was a general recognition of a north-south divide – with north koalas
possessing greater genetic diversity than their southern cousins.
2.106
Whilst the koala populations in Victoria and South Australia are more
numerous than those in New South Wales and Queensland, they are not genetically
diverse.[135]
This is the result of the large reintroduced populations of koalas in the
southern states originating from only a very few individuals.[136]
The TSSC described 'the majority of Victorian koalas, and all South Australian
koalas' as representing 'little genetic capital.'[137]
The TSSC observed that the low genetic variability of koalas in these areas
also 'reduces the population's ability to adapt to change, which may exacerbate
the effects of disease, over-browsing or climate change.'[138]
2.107
Whilst recognising the potential threat posed by low genetic diversity,
the TSSC indicated that 'other than isolated reports of individual deformities
that may or may not be due to inbreeding, there is no evidence at present that
population growth is being impacted by low genetic diversity.' Indeed, the TSSC
noted the somewhat counterintuitive fact that 'these [southern] populations are
mostly showing far greater levels of population increase than is the case for
the more genetically variable populations in parts of Queensland and New South
Wales.'[139]
2.108
The TSSC went on to explain that:
...we do not know what impact there may have been on the
functional variation that will determine how a population responds to new
environmental challenges. To be able to quantitatively assess viability of
southern koalas over a particular timeframe a population viability analysis
(PVA) model would need to be developed, taking into account all threats
including low genetic diversity.[140]
2.109
Despite the TSSC's rejection of a north-south genetic divide, several
submitters contended that such a divide does in fact exist. For example
Professor Frank Carrick informed the committee that the historic:
Near extinction (VIC) or complete extinction (SA) of Southern
Koalas coupled with widespread translocation from genetically impoverished source
populations has produced severe genetic homogenisation & loss of diversity.
In QLD by contrast, even the small & artificially established St Bees
Island population (small population & small island) has about twice the
allelic diversity of the most diverse VIC population and is more than [three
times] as diverse as the much larger (population & island) Kangaroo Island population
in SA.[141]
2.110
The Australian Koala Foundation argued that these [southern] populations
have been through 'at least 3–6 genetic bottlenecks and cannot be considered to
have a long term genetic viability'.[142]
Concerns about the sustainability of the 'southern' koala were shared by
several other submitters.[143]
2.111
Finally, Professor Carrick and other koala experts argued that there has
been little or no genetic interactions between the northern and southern
populations:
...mitochondrial DNA (mtDNA) data show that there has been
little or no gene flow between some populations for probably a few thousand
years. There is now essentially almost zero probability of gene flow between
the major Koala populations and there is compelling evidence that neutral
nuclear markers can differentiate in decades, not centuries.[144]
Concerns with current estimates
2.112
Due to a number of factors, such as the wide-range of the koala and the
inherent difficulty in counting the tree-dwelling marsupials, conducting
population surveys of koalas is difficult and expensive. Neither the
Commonwealth government, nor the state governments in jurisdictions where the
koala occurs has conducted extensive surveys of substantial koala populations.
2.113
It is clear from the evidence provided to the committee that there are
significant deficiencies in current population estimates. Advice from the TSSC
to the environment minister highlights this fact:
There is at present no published scientifically peer-reviewed
estimate of the total number of koalas in Australia and no definitive past
estimate within an appropriate timeframe to enable comparison.[145]
2.114
Members of the TSSC elaborated on this point in their evidence before
the committee. Professor Peter Harrison told the committee that the most
formidable obstacle to the TSSC's task of assessing whether or not the koala
should be listed as threatened is the:
...insufficient data on population size and trends across
many areas of the range of the koala. The lack of consistent long-term
monitoring populations throughout the range of this large, unmistakable diurnal
mammal clearly indicates that our nation has a long way to go to adequately
monitor and manage its biodiversity.[146]
2.115
The lack of a published scientifically peer-reviewed estimate of the
national koala population is a cause of frustration for conservationists,
scientists, government environment agencies and industry bodies.
2.116
For example, Koala Action Pine Rivers submitted that they 'consider that
estimates of koala populations are inaccurate in all the states of
Australia...' and 'question whether in fact the species is sustainable anywhere
in its natural range under current management practices'.[147]
2.117
Similarly, Professor Frank Carrick submitted:
...anyone who purports to give an accurate figure for the
koala population of Australia should be treated with deep scepticism (the data
does not exist) – BUT this is not really the key issue: the population trend is
far more important than absolute abundance and there are reliable data
available. Apart from the abnormal southern populations in Victoria and South
Australia, almost all other wild populations that we know about are in decline...[148]
2.118
Industry groups informed the committee that inadequate data on koala
numbers were creating poor planning outcomes and impacting negatively on
businesses. The Property Council of Australia argued that current broad based
mapping of koala habitat and populations 'have proved false upon further
investigation by the private sector'.[149]
2.119
According to the Property Council the poor surveying of koalas has led
to significant costs to the industry, including:
...substantial project delays, increased holding costs,
business uncertainty and substantial additional consultancy fees which have had
a direct impact on the ability to deliver affordability.[150]
2.120
The Urban Development Institute of Australia (Queensland) similarly
disputed the accuracy of current estimates of koala population numbers:
...in Queensland, issues around Koala population protection
are very substantially affected by emotional or other views based on values
which can lead to incorrect outcomes. It is critical that this hyperbole is
stripped away and true scientific measures utilised.[151]
2.121
In its most recent consideration of listing the koala as vulnerable
under the EPBC Act, the TSSC stated that 'better demographic data are needed'
to determine whether the koala is indeed vulnerable.[152]
According to the TSSC:
The body of data on the status of koala populations is
patchy, often sparse and not nationally comprehensive or coordinated. The data
quality is also variable. There has been only limited improvement in quality,
relevance and integration of these data over the 15 years that the koala has
been considered by this Committee and its predecessor. This situation is not
unusual for the Committee but what is unusual is the huge area of occurrence
and variability that the koala demonstrates. I[n] addition there is a lack of
any consistent reliable methodology for population monitoring of the koala.[153]
2.122
The TSSC commented that whilst there are some regions that have high
quality population data (such as south-east Queensland and some areas of
coastal New South Wales), many other regions have estimates based on anecdotes
or opinions, or are extrapolated from adjoining areas.[154]
2.123
It was recognised that on the best available information presented to
the TSSC that koala populations in south east Queensland and northern New South
Wales have experienced 'a generally consistent pattern of decline in recent
years'.[155]
However, some populations in South Australia and Victoria are increasing.[156]
The main threats to koala populations were recognised to be habitat loss and
disruption, impacts associated with cars and dogs and disease.[157]
2.124
In its professional judgement, the TSSC did consider 'that the national
population may have declined by about 30 per cent over three koala
generations.'[158]
However it went on to say:
Despite this the Committee has considerable uncertainty that
the figure it has reached and recommends that a final conclusion would require
that critical data gaps are filled.
The Committee recommends that this could be achieved by
giving urgent attention to koala population distribution and demographics in
Queensland and New South Wales.[159]
2.125
Professor Frank Carrick told the committee that the current situation in
which the TSSC requests additional data on koala populations without the
Commonwealth providing funding is proving to be the 'ultimate catch-22':
The Commonwealth authorities have persistently refused
applications to provide funding for koala surveys and establishment of
long-term monitoring sites. They then use the absence of detailed quantitative
data at intervening points on a broad scale as a reason to refuse to recognise
the clear evidence of the decline in those populations we do have hard data
for. Then they use that to justify failing to list the koala under the EPBC
Act, so this restricts access to survey and monitoring funds and so it ever
goes on. Move over, Joseph Heller! This is the ultimate catch-22.[160]
The way forward
2.126
The vast extent of koala range (over 1 million square kilometres), the
frequent low density of populations, as well as issues such as the sufficiency
of monitoring resources and access to remote regions, make large scale
assessment of the status of koala populations extremely difficult. To fill the
gaps in population data, it was suggested by koala researchers that long-term
monitoring of key koala populations (such as the Mulga Lands of western
Queensland and Mumbulla State Forest on the south coast of New South Wales) be
established.[161]
2.127
Dr Alistair Melzer recommended that koala ecology monitoring stations in
key biogeographic regions and zones of interest be established to monitor
trends over a number of years.[162]
2.128
The Koala Research Network believes that key long-term monitoring
stations would give more accurate and diverse data on koala populations which
is required for their conservation:
Long term monitoring data to estimate trends are much more
important than just knowing how many animals there are because this tells
something about the direction and rate of change.[163]
2.129
A second priority raised by the Koala Research Network in conducting
population research was for the koala research community to adopt a national
approach to koala monitoring:
It is becoming increasingly important to develop national
standards and guidelines for assessing and comparing the overall health status
of koala populations and for deriving meaningful population estimates. This
work will be vital for ongoing prioritisation of recourses and conservation
programs, for monitoring trends, and for evaluating the performance of
conservation measures.[164]
2.130
The Conservation Council ACT Region also agreed with the need to develop
better standards for monitoring population trends while acknowledging the
legitimacy of different perspectives.[165]
2.131
A lack of funding was also highlighted by the University of Queensland
Koala Ecology Group as hindering the gathering of accurate data on koala
populations. According to the group:
Koala population estimates have, in the past, relied
generally on indirect methods of assessment, probably as a result of a lack of
funding limiting more comprehensive investigations. As a result, there is some
uncertainty about the extent of koala declines in areas of their range...Were
these studies properly funded from the beginning, it is unlikely that the
current data gaps would exist.[166]
2.132
The National Koala Conservation and Management Strategy 2009–2014
contains as one of its outputs the need to develop a better understanding of
koala population requirements and maintain an information network to guide
planning and natural resource management processes.[167]
Two direct actions are listed in the strategy to achieve this output:
- develop standard monitoring/habitat assessment protocols to
enable population numbers or density to be compared between the same place at
the same time; and
- establish a national database of koala population distribution
and density to facilitate planning at all scales that is accessible by relevant
authorities.[168]
2.133
The first implementation report of the National Koala Conservation
and Management Strategy 2009–2014 , showed that apart from some limited
activity in NSW, nothing is being done to develop standard monitoring
protocols.[169]
The major activity listed to establish a national koala database is ongoing
discussions between the Australian Government and the Atlas of Living
Australia.[170]
2.134
The TSSC has also advocated for a national koala monitoring and
evaluation program:
A properly designed, funded and implemented national koala
monitoring and evaluation program across the full range of the koala is
imperative. This should be part of the proposed National Environmental
Reporting System and would coincidentally provide valuable data on a number
of other important species, and areas of key habitat for achieving conservation
objectives.[171]
2.135
The TSSC indentified priority areas as:
...(1) broad-scale
sampling/survey (to provide distributional and abundance information) in those
regions for which koala occurrence is least known (particularly including
Desert Uplands, Brigalow Belt, Einasleigh Uplands, and central coast of
Queensland, as well as inland NSW). The public mail survey method (or an online
equivalent) used by Lunney et al. (2009) may provide a useful initial mechanism
for this inventory. (2) continue to monitor koalas (and their food trees) in
the Mulga Lands region, to assess the extent of recovery (if any) following the
cessation of the drought.[172]
Committee comment
Difficulties measuring koala
numbers
2.136
The committee acknowledges the inherent difficulties in measuring koala
numbers. Making an accurate count of these tree-dwelling marsupials which remain
motionless for large parts of the day and which are scattered throughout a
range of more than one million square kilometres will always prove highly
challenging. In the committee's view this will be an ongoing aspect of
determining koala numbers and assessing their status under the EPBC Act
(discussed in chapter 5). The committee accepts that the exact koala population
is unknown and that there has been no comprehensive counting of koala numbers
across the country.
2.137
For this reason the committee believes it is preferable to focus on an
estimated population range rather than a precise population number. In this
regard the committee notes the most often quoted national estimation of koala
populations comes from the Australian Koala Foundation which estimates a
minimum of 43 000 koalas left in Australia and a maximum of 84 000. The
committee also notes the TSSC's alternative estimate of the national koala
population in 2010 was 'about 300 000', with a 'plausible lower bound' of '
about 200 000 individuals'.[173]
2.138
These figures compare with the TSSC's 1990 estimate of the national
koala population of 430 000 individuals.[174]
2.139
The committee accepts the 'data-interpretation challenges' faced by the
TSSC and its observation that the species 'lacks precise population trend data
in significant parts of its range.'[175]
These challenges in population data were also expressed by the TSSC in the 2006
attempt to list the koala.[176]
Marked decline
2.140
The committee agrees that the available scientific research points to a marked
decline in the overall koala population,[177]
with several important areas suffering very significant declines. However the committee
accepts that the extent of this decline across the country is not fully known
and also that some koala populations, primarily in southern Australia, appear
to be stable or increasing. The committee notes however that in many areas
across its range the koala population is expected to continue to decline.
Regional trends
2.141
From the evidence presented to the committee two generalised regional
trends in the koala population are apparent. Broadly speaking, koala
populations scattered throughout parts of Queensland and New South Wales are
showing 'a consistent pattern of decline'. This trend was anticipated as far
back as the mid-1980s by the National Parks and Wildlife Service in the National
Koala Survey. Koala numbers in some regions, such as south eastern
Queensland and parts of costal New South Wales, have been accurately counted.
In these populations it is clear that koala populations are declining
significantly. The committee also notes that koalas in Queensland and New South
Wales provide the highest genetic diversity across the species range.
2.142
By contrast the populations in Victoria and South Australia are in
general relatively abundant and stable, with certain populations increasing and
requiring active management to prevent habitat destruction through
over-browsing. In areas where koala numbers have become overabundant, such as
Kangaroo Island in South Australia and French Island, Raymond Island and Tower
Hill State Game Reserve in Victoria, state governments have implemented sterilisation
and translocation programs to mitigate these impacts. The committee notes that
koalas in these areas originate from limited genetic stock and consequently
display much lower genetic diversity, with some submitters questioning their
long-term viability. The committee also notes that the abundant populations in
Victoria are largely 'a function of the translocation program that has been
operating for several decades.'[178]
2.143
To resolve this situation, and to address the potential for large
depauperate southern populations from skewing the national koala estimate, the
committee believes there is a need for further scientific research into the
genetic diversity of the koala. This should include a population viability assessment
as recommended by the TSSC for the southern koala as well as a thorough genetic
analysis across the entire range of the population. The committee notes the
difficulties expressed by submitters and witnesses in previously securing such
funding and accordingly recommends that the Australian Government fund this
important research. Such a study would allow an assessment to be made about the
viability of the bottlenecked populations of the south and better
identification of priority conservation areas, such as the Strzelecki and
Mumbulla populations.
Recommendation 1
2.144 The committee recommends that the Australian Government fund research
into the genetic diversity of the koala including a population viability
assessment of the southern koala and determining priority areas for
conservation nationally.
Population data deficiencies
2.145
The committee is concerned about the deficiencies in koala population
data, both current and historical. More robust information on the koala's
population status will necessarily lead to better decision-making about the
most important and effective conservation and management strategies.
2.146
In the committee's view, if the koala's long‑term viability is to
be secured for future generations, then there is a critical need for better
population information. Clearly, more resources and dedicated commitment are
needed to achieve this outcome and the committee recommends greater
Commonwealth involvement in this area, including through the provision of financial
support. In this regard the committee supports the TSSC's call for 'a properly
designed, funded and implemented national koala monitoring and evaluation
program across the full range of the koala is imperative.'[179]
Recommendation 2
2.147 The committee recommends that the Australian Government fund a properly
designed, funded and implemented national koala monitoring and evaluation
program across the full range of the koala.
2.148
This could be facilitated as part of the Koala Research Network's
integrated research proposal which is supported by the committee and which is
discussed further in Chapter 4.
2.149
To effectively implement such a program, the government must encourage
relevant state and local governments as well as community and business
organisations to participate fully in this initiative. The government should
also give preference to 'critical data gaps' such as those identified by the
TSSC in Queensland and New South Wales.[180]
In particular, urgent priority should be given to 'broad-scale sampling/survey...in those regions
for which koala occurrence is least known (particularly including Desert
Uplands, Brigalow Belt, Einasleigh Uplands, and central coast of Queensland, as
well as inland NSW)' and to 'continue to monitor koalas (and their food trees)
in the Mulga Lands region [in Queensland], to assess the extent of recovery (if
any) following the cessation of the drought'.[181]
Availability of biodiversity
information
2.150
On the related matter of the availability of biodiversity information
more generally, the committee notes the TSSC's statement to the Environment
Minister that:
...the interpretative challenge of determining the status of
the koala is a symptom of a more general problem. Biodiversity in Australia is
in decline but the available data to inform priorities and actions are
generally inadequate, being both insufficient and uncoordinated. A consequence
is that we are not making well informed investment decisions. The Committee
would welcome a formal request from you to provide an advice on this critical
issue.[182]
2.151
The TSSC elaborated on this point in its response to the committee's
questions on notice:
We recommend a nationally coordinated integrated program for
population monitoring of threatened plant and animal species (and other species
of cultural, evolutionary and/or economic significance). Such monitoring should
(i) provide timely warning of unacceptable declines that automatically triggers
alerts that require immediate management actions to ameliorate or halt the
decline to enable population recovery, (ii) measure the effectiveness of
conservation management responses (and hence help continually refine and adapt
that management), and (iii) provide a headline index of the nation’s
environmental progress that can be counterpointed with more traditional
economic and human demographic indices.[183]
2.152
The committee supports this perspective, and in particular the TSCC's
caution regarding poorly informed investment decisions and the need for a nationally
coordinated and integrated program for population monitoring of threatened
species and other culturally, evolutionary and/or economically significant
species.
Recommendation 3
2.153 The committee recommends that the Australian Government establish a nationally
coordinated and integrated program for population monitoring of threatened
species and other culturally, evolutionary and/or economically significant
species.
Standardised counting methodologies
2.154
The committee notes the range of methods used by different researchers
and organisations to count koalas. The committee acknowledges that there may be
preferred methods depending on the location and population density as well as
other relevant factors. However, in the committee's view the suite of different
methodologies has led to a degree of unwanted and unnecessary uncertainty
regarding koala population estimates. The committee supports the consolidation
of counting methods, and encourages researchers and other interested
organisation to collaborate in order to agree to a set of standardised counting
methods. This is not an endorsement of a single methodology to be used across
the entire country, but instead a proposal for an agreed set of methodologies,
with each to be used in an agreed set of circumstances.
Recommendation 4
2.155 The committee recommends that the Australian Government assist the koala
research community and interested organisations to work towards a standardised
set of methodologies for estimating koala populations.
TSSC advice
2.156
In addition to supporting the gathering of better population data and
the adoption of standardised counting methodologies, the committee believes
that the Environment Minister must be presented with the best available
information upon which to base his or her listing decision. In this regard the
committee has some concerns about the TSSC's advice provided to the Minister in
September 2010.
2.157
For example, on the critical question of the current koala population,
the TSSC simply advised the Minister that 'the koala population is greater than
200 000 individuals'. However it is unclear from the TSSC's analysis of the
existing population data, how it determined this figure.[184]
Although it did provide a national estimate (300 000) and a 'plausible
lower bound' (200 000) for this inquiry, the TSSC did not provide either of
these figures to the Minister. Similarly, the TSSC did not provide the
necessary figure for historical comparison to the Minister, despite providing
it (430 000 in 1990) to the committee for this inquiry.
2.158
It is surprising to the committee that nowhere in its advice to the Environment
Minister, did the TSSC include its conclusion that the national koala
population in 2010 was 300 000. The only figure that was included was the
figure of 'greater than 200 000 individuals' which itself was included at page
27 of its advice. In the committee's view, whilst acknowledging the complexity
of its task of assessing the conservation status of species against the
detailed EPBC Act criteria, the TSSC must be far clearer in its future advice
to the Environment Minister. Headline information, such as species population
figures, must be presented in an easily understandable manner and in a
prominent position within the advice.
2.159
In the committee's view it is imperative that the statutory body, which
has a legislated role to provide advice to the Minister on the conservation status
of species being considered for listing as threatened,[185]
provides its assessment of the population range (both current and historical)
based on the best available information. The committee acknowledges that the
constraints of current best available information may lead to a wide population
estimate range. However, without such a range, it must be very difficult for
the Minister to make an informed decision on the current listing assessment for
the koala as well as other listing decisions. Given the inherent difficulties
in obtaining accurate koala numbers, without clear TSSC guidance on an
estimated population range, the Minister is put in a very difficult position. As
data deficiencies are not unique to the koala's circumstances, it is vital that
for all future listing assessments, the TSSC provide the Minister with the
clearest information possible, based on the best available information.
Recommendation 5
2.160 The committee recommends that the Threatened Species Scientific
Committee provide clearer information to the Environment Minister in all future
threatened species listing advices, including species population information,
and that the Threatened Species Scientific Committee review its advice to the
Minister on the listing of the koala in light of the findings of this inquiry.
2.161
Further discussion on the related matter of the threatened listing of
the koala is included in chapter 5.
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