Koala sheltering in the shade of a tree during a heatwave. (Photo: Greg Gordon)
condition and had a low mortality rate. Surprisingly, observers also found the highest mortality rates among young animals, which may have been excluded from optimal sites by older, dominant animals.55
In Chapter 8 we looked at the problems of overpopulation that can occur on islands, but a number of isolated mainland populations have also become overpopulated. After the prohibi tion on hunting, koala population numbers soon began to rise, particularly in Victoria. The theory of population regulation was first proposed in 1798 by the political economist Thomas Malthus.56 Malthus observed that, in nature, plants and animals (including humans) produce far more offspring than can be supported by the amount of food available. He suggested that poverty and famine were the natural and inevitable outcomes of population growth and limited food supply, a view unpopular among social reformers who believed that proper social structures could eradicate all the ills of man.
Charles Darwin and Alfred Russell Wallace independently arrived at similar theories of evolution via natural selection. Unlike Malthus, they looked at the principle in purely natural terms. By doing so, they extended Malthus' logic and realised that producing more offspring than can survive establishes a competitive environment among siblings. This led them to propose that the variation among siblings would produce some individuals with a slightly greater chance of survival than others. It appears that in the case of some koala populations, natural regulation to avoid overpopulation (and over-exploitation of the available food resources) does not occur. Koala populations that were maintained at sustainable levels through hunting by Aborigines and predation by dingoes will increase rapidly if these regulatory factors are removed. There are also several other factors that may have assisted in the growth of population numbers including the expansion into areas where eucaltypts were re-growing following settlement and land development, increased availability of nitrogen-rich foliage in the early stages of dieback, and a release from plant defences.57
The koala overpopulation problems in Victoria and South Australia are often the result of a habitat fragmentation which does not allow adequate dispersal. The reasoning behind koala overpopulation is not controversial, but the management of overpopulated habitats is perhaps the most emotive issue in koala conservation.
In Chapter 8, we looked at what happened at Kangaroo Island, but this was not the only occasion to demand the culling of a koala population. Since 1914, severe overpopulation and degradation of habitat to the point of large-scale koala mortality have been documented on at least five occasions in Victoria: Wilson's Promontory (1914); Quail Island (1943-44); Walker-ville (1978-80); Sandy Point (1988-89); Framlingham Forest (1994-98); and Snake Island (1997-98).58
The earliest recorded overpopulation of koalas at Wilson's Promontory occurred only after it was proclaimed a National Park in 1905. It is possible that the area had been overpopulated for many years, as hunters were known to take an average of 2000 pelts per year.59 After the National Park was established, the koalas became so abundant that overbrowsing began to kill the eucalypts. The Victorian Government allowed 50 animals to be culled, but the koalas were now so numerous that this did not solve the problem. Most of the koalas' food trees died and the koala population collapsed, but subsequently recovered.60
Today, Parks Victoria manages a number of sites where over-browsing has caused extensive habitat defoliation and put many koalas in danger of starvation. These include Mount Eccles National Park, Tower Hill, French Island, Snake Island and Raymond Island. Typically, the problem of overpopulation has been managed by translocation, however over time the rationale behind this approach has changed. When government-run translocations first began in 1923 the primary purpose was to create secure island koala populations. When these island populations began to outgrow their habitats, the reintroduction phase aimed to transfer koalas to habitats where they had once occurred.61 By the mid-1980s, the emphasis had shifted again, this time to habitat protection. Between 1923 and 2006 translocations from Victorian islands took place in 67 of those 73 years, with a total of 16 405 animals being moved from seven overpopulated islands. A further 7665 animals were transferred from Victorian mainland habitats between 1946 and 2002.62 As a result of these transactions over 24 600 individual animals have been translocated to over 250 release sites across Victoria.
Translocation programmes not only require substantial financial investment to be successful, but can inflict other, long-term costs on the koalas themselves. The reduction of koala populations to very small numbers leads to what is called a 'genetic bottleneck' as the populations' genetic diversity is greatly reduced. Low genetic diversity as a result of inbreeding reduces fertility and reproductive success, can affect the koalas' immune system and increase the mortality rate through disease. Any subsequent translocation of a small number of animals from an already inbred population only exacerbates the inbreeding problem. This is why the koalas on Kangaroo Island and in some of the remnant habitats on the Victorian mainland are all inbred as well as overpopulated.
Recent genetic studies confirm that the translocation programmes operating in south-eastern Australia have resulted in cumulative inbreeding and the loss of genetic variation in many populations, particularly on French Island in Victoria and on Kangaroo Island and the Eyre Peninsula in South Australia. The inbreeding has reached such an extent that it now poses a serious threat to the koala's long-term survival in these areas.63 Ayesha Seymour and her colleagues found significant morphological abnormalities in some koala populations, such as testicular dysplasia (or abnormal development), which can result in failure of one or both testicles. In some cases, the defect rates were as high as 30 per cent. They suggest, however, that many of these issues could be addressed by altered management strategies, such as introducing unrelated stock into inbred populations.64
As we have seen, habitat loss and fragmentation can impact on koalas in various ways, and another significant risk factor directly linked to land clearing is road traffic. South-east Queensland is one of Australia's most rapidly developing areas of Australia. At the same time, it is also home to one of the country's largest koala populations. For some years now, researchers have been tracking the increasing impact of residential development and the accompanying road traffic on the region's koala population. In 1985, mounting concern over the koala road toll led the Queensland Parks and Wildlife Service to begin recording koala sightings within the Koala Coast. The Koala Coast is an area of approximately 400 square kilometres south-east of Brisbane, which comprises the mainland component of Redland Shire and parts of Brisbane and Logan cities. The Koala Coast has an estimated koala population of 5000 to 6000, of which one-third reside in urban areas.65 The impact of urbanisation on the area's koalas can be seen in that by 1988 two community-based groups, the Eprapah Scout Association and the Koala Preservation Society had been established in the Redland Shire to care for sick, injured and orphaned koalas.
Increased urbanisation fragments koala habitats, forcing the animals to move from habitat to habitat, and run the gauntlet of hostile obstacles such as cars and dogs. More and more koalas are being killed or injured. For example, between 1993 and 2000, one vet in the Noosa region of south-east Queensland received 87 koalas. Of these, 32 had been hit by cars, 16 of which could not be saved; nine had been attacked by dogs, seven of which died; 35 animals were diseased, only four of which survived; three had heavy tick loads, one died; and eight animals were considered to be healthy.66
In 1990, the increasing numbers of koalas requiring veterinary attention in the greater Brisbane region led the Queensland Parks and Wildlife Service to set up the Moggill Koala Hospital.67 In its first year of operation, 89 koalas were admitted to the hospital. Redland Shire Council realised the shire's need for a koala ambulance and volunteers were recruited and trained to operate the service. Unfortunately, the sheer number of sick and injured koalas from the Koala Coast meant that the service soon was struggling to meet demand and the Logan Koala Association funded a second ambulance, which began operation in December 1993. In May 1995 the Daisy Hill Koala Centre, manned by wildlife rangers, was opened.68 All the region's sick and injured koalas eventually find their way to the Moggill Koala Hospital, which by 1995 had doubled its intake of koalas and continues to grow rapidly.
In 1999 the Moggill Koala Hospital admitted 1223 koalas: 352 traffic accidents; 153 dog attacks; 146 with cystitis; 110 with conjunctivitis; and 97 with pneumonia.69 The hospital is now finding that increasing numbers of female koalas taken to the hospital for trauma have no overt signs of disease, but on ultrasound examination are shown to have ovarian cysts. These animals have to be euthanased, because experience has shown that these cysts only increase in size, leading to suffering and eventual death. As these animals are infertile, it is not known what impact their absence has on the population.
Hospital records also reveal that dog attacks peak in September each year, which may be because more koalas are moving between habitats in the search for mates. Other research found that between 1997 and 2003, dog attacks accounted for some 1000 admissions to the Moggill Koala Hospital.70 Attacks by medium (11—25 kilograms) and large (over 25 kilograms) dogs are 20 times more common than attacks by small dogs. Only 4 per cent of attacks were by dogs weighing less than 10 kilograms. Eighty per cent of koalas attacked by dogs either die from their injuries or are eutha-nased. This high mortality rate is supported by other studies that suggest that dogs' impact on koala populations is much larger than previously thought.71
The high numbers of koalas requiring Moggill Koala Hospital's services raises very worrying issues, such as the impact of the increasing mortality rate on the long-term viability of the region's koala population. What, if anything, can be done to stop the spiralling death rate? As we will see in Chapter 11 there are efforts being made to reduce the death rate of koalas in regions where they co-exist with humans, but as yet these have had limited success.
In northern New South Wales, Port Macquarie's Koala Hospital was the first veterinary hospital dedicated solely to the care of koalas. It was founded in 1973 by a local couple, Jean and Max Starr, and is now run by the Koala Preservation Society of New South Wales. The hospital has a treatment room, six intensive care units, a 24-hour rescue and treatment operation and multiple recovery yards. The facility also has a research affiliation with the University of Sydney. It is a 'C' class veterinary hospital, that is, only minor procedures can be carried out on site. All major surgery, X-rays and so on take place at the Veterinary Superintendent's practice in Port Macquarie. Over its 32 years of operation, the hospital has developed a number of protocols and procedures for dealing with the various symptoms presented by its patients. Some have proved highly successful, while others are continually being trialled and reassessed with a view to further improvement. The hospital has an excellent record against eye infections caused by the Chlamydia bacteria, although the battle against the urogenital form of Chlamydia is still to be won.72
The koala has evolved to overcome the real challenges faced by its own food source and habitat but, as we have seen in this chapter, the koala also faces significant threats from habitat loss, disease outbreaks (perhaps triggered by stress), bush fires, dog attacks and road accidents. Not a promising outlook, is it? On the plus side, however, increased public awareness of and concern about the impact of human settlement on the koala has mustered an army of individuals committed to giving the koala a helping hand. Despite the establishment of specialised koala hospitals and localised public education programmes, large numbers of koalas are still being killed each year either directly or indirectly by humans. The koala's greatest need is for we humans to establish strong, enforceable management practices, especially in land use planning, that will protect koala habitat and minimise koala losses.
The highs and lows
Current available evidence indicates that the koala has declined in recent years. However, the Threatened Species Scientific Committee (the Committee) has advised that the evidence indicates that the koala has not undergone a substantial reduction in numbers, equivalent to 30per cent or more of the total population, across its national range over the past three generations. The Committee also advised that there is no evidence to indicate that it is likely that there will be a substantial reduction in numbers, equivalent to 30 per cent or more of the total population, across its national or natural range over the next three generations . . . After careful consideration of the issues and the Committee's advice as outlined above, I have therefore decided that the koala is not eligible for listing under the EPBC Act criteria. Thus, I cannot include the koala in any category of threatened species.1
As we have seen in the preceding chapters, since the time of European settlement koala numbers have fluctuated. At the end of the 18th century, their numbers appear to have been quite low; the 19th century saw a dramatic increase before the fur industry and habitat loss caused the numbers to crash. Since the 1950s, koala numbers in certain regions have recovered, too much so in some areas, but overall population numbers have decreased dramatically. In this chapter, we will look at trends in koala numbers and the koala's current conservation status, as well as the practical applications of conservation and the controversies associated with koala management.
Before entering into any debate on the conservation of the koala, it is important to put its current population size and distribution into context. As we explored earlier, it was ten years after settlement before the koala was discovered by Europeans, and early explorers and naturalists record relatively few animals. Their rarity in eastern New South Wales and southeastern Queensland led John Gould to suggest they would soon become extinct.2 In contrast, however, George Augustus Robinson, Chief Protector of Aborigines in Victoria's Port Phillip district, observed high numbers of koalas in 1844. Robinson was the first to link the demise of the Aborigines to the increase in koala populations, observing that numbers of many forest animals, particularly koalas and lyrebirds, were rising as the local Aboriginal tribes declined.3
Harry Parris made similar observations. He recalled that in the 1850s, when his family first moved to the Goulburn River near Nagambie in Victoria, they rarely saw koalas. By the late 1860s they were much more abundant, with five koalas being shot in the one tree. Numbers increased dramatically, until by 1890 koalas could be seen in their thousands. To explain this increase, Harry Parris recalled that local Aborigines hunted koalas on a daily basis and he deduced that 'the bears increased as the blacks decreased'.4 The rapid decline in numbers of Aborigines in Victoria appears to be the result of smallpox,5 and it is estimated that the population plummeted from 15 000 in 1834 to less than 3000 by 1851.6
Records in New South Wales support the theories of George Augustus Robinson and Harry Parris. We have already seen how koala numbers in Bega, for example, showed a dramatic increase as the numbers of local Aborigines declined. A Census for the period 1841-45 records only 160 Aborigines in the District of Monaro, which included Bega. By 1871, this number had fallen to 33.7 Although an important contributory factor, the decline of the Aborigines is not the sole mechanism that allowed koalas to increase—in central Queensland, for example, koala numbers continued to increase after 1900, long after the decline of the local Aborigines. It is important to remember that numbers of another of the koala's natural predators, the dingo, were also falling. Concerns about the animal's predation on livestock led many European settlers to shoot dingoes on sight.8
Opinions differ as to the primary cause of the decline in koala numbers, although the various contributory factors are not disputed. Some blame the fur industry, others habitat clearing or the bushfires associated with European settlement, while others suggest epidemic disease.9 The impact of the most emotive issue, the fur trade, has long been debated. Ronald Strahan and Roger Martin take the dispassionate view that 'Europeans had not suddenly become bloodthirsty, but simply that a fur-bearing species had become available in sufficient numbers to justify its exploitation'.10
Some have proposed that hunting reduced both the range and abundance ofVictoria's koalas, but despite the large numbers killed, others do not consider hunting to be important in the decline of koalas in either Queensland or New South Wales.11 It seems clear, however, especially in Queensland, that although koala numbers were high in some regions, once the culling began it was difficult to stop. It also appears that political expediency and the money generated by the trade in koala skins combined to drive the fur trade far beyond what was sustainable. As we saw in Chapter 9, however, one positive outcome of the 1919 and 1927 culls in Queensland
was the public outrage that gave rise to the koala conservation movement.
To manage Australia's koalas effectively, it is important to understand their current distribution. The koala is restricted to the east, south and south-east of the continent, where it inhabits a range of eucalypt forests and woodland communities, including coastal forests and woodlands. The suitability of those forest and woodland communities as koala habitat is influenced by a range of factors including the species and size of trees present, soil nutrient levels, climate, rainfall, structural diversity of the vegetation and the habitat patches' disturbance history.
Within its broad limits, what is the koala's distribution today? They are somewhat out of date now, but the data collected during the National Koala Survey of 1986-87 still offers some important insights.12 Most koala populations now survive in fragmented and isolated habitats, with many areas where koalas are most abundant under intense and ongoing pressure from agriculture and urban expansion. In Queensland the koala was found to be abundant in a number of areas, but the greatest concentrations were in the state's south-east which is also home to most of Queensland's human population. Outside the south-east of the state, koala populations appear to be relatively good in many areas, though invariably at a low density. The data show, however, that koala populations in northern Queensland are less abundant than in the past, suggesting a southward contraction of their range. These observations are supported by a more recent detailed assessment of the decline in the distribution of Queensland's koalas which revealed that the broad distribution had contracted by about 27 per cent and the area occupancy had decreased by about 31 per cent.13
In New South Wales, the National Survey found koalas to be uncommon or rare in the majority of localities. The highest numbers were found along the state's north coast, with an extensive but highly fragmented distribution west of the Great Dividing Range and in the southern half of the state. Prior to the first official koala survey in 1949, records suggest considerable numbers of koalas in central and western New South Wales. The National Survey revealed that many southern, central and western koala populations had disappeared, indicating that their distribution was contracting towards the coast.14 With the exception of those in the central west of the state, the largest koala populations in New South Wales are in coastal areas where their habitat is under increasing threat from urban development. One of the key reasons for the koala's decline in New South Wales was proposed by Philip Reed and colleagues who suggested that its distribution is linked to tree species found in high-nutrient soils such as those in river valleys, soils which are much sought after for agriculture and timber production.
In Victoria, the National Survey found that the koala's distribution largely reflected the state's translocation programmes. As we discovered in Chapter 10 over 24 600 koalas have been translocated to over 250 sites, which has re-established the koala through much of its former range. In South Australia, the koala's distribution is probably wider than at any time since European settlement, which is entirely due to translocation.15 In 1923, when the koala was close to extinction on the South Australian mainland, it was re-introduced on Kangaroo Island.
Koalas from Queensland, New South Wales and Victoria were also introduced to the Mount Lofty Ranges and subsequently established at Riverland.16 The 1983 wildfires took a heavy toll on the Mount Lofty Ranges population, but it is now largely recovered.17 In 1969, koalas were introduced to the Eyre Peninsula and to their former range in the state's south-east.18
Their distribution might be wide, but their numbers are not uniformly abundant across their range. Koala numbers are determined by geographical location, sustainability of their existing habitat and the extent of habitat loss.19 In central Queensland, for example, koala populations with densities as low as one animal per 200 hectares have been discovered.20 Studies in Victoria's Brisbane Ranges found densities of 0.7 to 1.6 animals per hectare, while population densities of between 6.0 and 8.9 animals per hectare have been recorded on French Island. Densities as high as eight animals per hectare have been found in the Strathbogie Ranges in north-eastern Victoria— more than a 1000-fold increase in abundance over the central Queensland populations.21
With all the threats that have menaced the koala since the arrival of Europeans, is it endangered with extinction? In 1996 the Australasian Marsupial and Monotreme Specialist Group undertook a formal review of the koala's status. A number of koala specialists carefully considered the koala in line with criteria developed by the International Union for the Conservation of Nature and Natural Resources (IUCN). They determined that despite an estimated reduction in its geographic range since European settlement of greater than 50 per cent, the koala was considered 'common throughout the broad band of forests and woodlands dominated by Eucalyptus trees, extending from Queensland to the south-eastern corner of mainland South Australia'. The review proposed that, at a national level, the koala did not meet the criteria for listing as a threatened species, but it acknowledged that the koala was potentially vulnerable by granting it the conservation status of 'lower risk' ('near-threatened').22 The koala's conservation status was being hotly debated before this assessment and the review's controversial finding ensured that it continues to be so.
What is the difference between 'lower risk' and 'vulnerable'? The IUCN has developed a complex set of guidelines to assess the likelihood or risk of a species becoming extinct. The criteria are based on the degree of habitat loss, population reduction, population fragmentation and reduction in overall distribution. A species' risk of extinction is known as its 'conservation status' and ranges from 'extinct', where all individuals of a species are thought to have died; 'critically endangered' where a species is facing an extremely high risk of extinction in the wild in the immediate future; 'endangered' where a species is not critically endangered but does face a high risk of extinction in the wild in the near future; and 'vulnerable' where a species is not critically endangered or endangered but does face a high risk of extinction in the wild in the medium-term future. A species which is not considered threatened with extinction is classed as 'lower risk'.23
One of the key organisations committed to promoting the koala, especially its conservation and education of the public, is the Australian Koala Foundation or AKF. The AKF was founded by two veterinary scientists, Barry Scott and Steve Brown, who registered the Australian Koala Association Inc. in 1986.24 Later the same year, the name was changed to the Australian Koala Foundation Inc., but the 'Inc' was subsequently dropped. Each year in Australia, the AKF runs a springtime public appeal, such as Save the Koala Month each September. The last Friday of that month is Save the Koala Day, and uses slogans such as 'No tree, no me' and 'Think spring, think koalas'. The AKF's aim is to raise awareness of the koala's plight at the same time as educating people on wider conservation issues. They also play an important role in undertaking koala research, providing advice to assist koala conservation, and advocating the koala in the media and during public debates on various issues. They raise money through sponsors, sales of stickers, badges, special gifts, items and donations.
Australasian Marsupial and Monotreme Specialist Group recorded in their report that the AKF disagreed with their allocation of the koala as 'lower risk', proposing the koala was at least 'vulnerable' if not 'endangered' with extinction. At the same time, the AKF were petitioning the Australian Government to include the koala in the Endangered Species Protection Act 1992 as 'vulnerable', an application which would prove unsuccessful.25
Before the Australasian Marsupial and Monotreme Specialist Group had given their decision on the koala's status, on 5 May 1995 several animal welfare groups including Australians for Animals and Fund for Animals (in the United States) petitioned the United States Fish and Wildlife Service to classify the koala as 'endangered' in New South Wales and Victoria and 'threatened' in Queensland. They listed some 40 American and Australian organisations, including the AKF and Humane Society International, and several leading scientists as supporting the petition. The petition was opposed by representatives of every Australian state government where koalas occur in the wild and the Australian Government, who questioned how the koala's 'endangered' listing in the United States would contribute to its conservation. On 9 May 2000, the welfare groups' application was successful, and on 8 June 2000 the koala was listed as 'threatened' under the United States Endangered Species Act 1973.26 The 'endangered' list also includes the great apes, Asian and African elephants, giant pandas, rhinos and tigers, although at one point you could have found three of the most abundant of all the Australian marsupials—the eastern grey kangaroo, western grey kangaroo and red kangaroo! These embarrassing inclusions were removed from the list on 10 April 1995.27 The koala's listing means that United States federal agencies must consider the impact of their actions on the koala and prohibits any commercial activity or trade in koalas by the United States of America, except under a 'threatened species' permit.
The American Government included the koala on their 'endangered' list because of a perception that the species was not being managed properly in Australia, and the listing came under immediate criticism from the Australian Government. The then federal minister for the environment and heritage, Robert Hill, took the extraordinary step of issuing a media release titled 'Koalas abundant despite US endangered listing', in which he stated that the 'decision by the United States Government to list the koala as threatened under the US Endangered Species Act is inappropriate and unnecessary'. He went on to say that the decision 'ignores available scientific data on the abundance of koalas in Australia' and that 'the US listing misrepresents the status of koalas in Australia and is superfluous to wildlife management issues'. He concluded by saying that 'the US decision will not contribute to the conservation of the species in Australia'.28
While the American Government was considering the koala's conservation status, in 1998 the Australian and New Zealand Environment and Conservation Council (ANZECC) developed a National Koala Conservation Strategy. ANZECC also considered the koala not to be endangered 'at this time', but acknowledged that koala numbers were declining in parts of its range, and the animal's cultural significance meant there was much public debate and scientific concern about its conservation.29 Shortly after this, Stephen Phillips, formerly of the
AKF, correctly pointed out that complex factors including food tree preferences, history of habitat disturbance and Chlamydia infection limit free-ranging koala populations and make it difficult to predict long-term population trends. At the conclusion of his review, he suggested that koalas should be considered 'vulnerable to extinction'.30
Undeterred by the lack of success of their 1996 petition, in 2004 the AKF lodged a further nomination for the koala to be considered 'vulnerable' at the national level with the Australian Government.31 In 2006, the AKF was advised that their application had been unsuccessful, prompting them to claim that 'Government washes hands of koala problem'.32 The AKF subsequently wrote to Senator Campbell as part of the preparations for Save the Koala Day.33 In this correspondence they suggest the minister's Threatened Species Advisory Committee had ignored recent research. The assessment of species under IUCN criteria does not look at predictions, but what has happened in the last ten years, or three generations, and seeks a 30 per cent decrease in population size for a species to be considered vulnerable. The koala does not qualify, under these criteria. What is really at issue here is that the IUCN's threatened species approach is not appropriate for evaluating a widespread species under significant threat in major parts of its range.34
The minister's decision seems to be supported, at least as far as Queensland koalas are concerned, by research undertaken by Greg Gordon, Frances Hrdina and Ross Patterson. Their extensive review of the decline of koalas in Queensland showed that the overall area of occupancy of koalas in Queensland had decreased by 31 per cent over 100 years. However, this contraction in distribution, for the koala to be listed as 'vulnerable' in Queensland or the South-east Queensland Bioregion, would have required a 30 per cent decline over only 15—20 years.35
So what is the koala's current 'official' status in Australia, and how does it vary between the states? At a state level the koala's conservation status varies enormously. In New South Wales it is listed as 'vulnerable' and in South Australia as 'rare'. However, elsewhere it is not considered threatened, except in the South-east Queensland Biogeographic Region.
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