Habitat clearance, disease, dog attacks, car hits, and climate change are threatening the survival of Australia’s most iconic animal.
The effects of climate change on koalas and the ravages of diseases such as chlamydia were main issues raised at a national conference about the beleaguered animal, and delegates heard that koalas are already functionally extinct in some areas of Australia.
There were some success stories, such as the population of koalas increasing to more than 3,000 in the Southern Highlands of New South Wales, and positive collaboration with the local council in Ipswich, and there have been numerous advances in scientific research.
However, koalas continue to die in their thousands as their habitat disappears, and they are killed by dogs, in car hits, and in bushfires.
It was made clear at the conference that, for koalas to survive, protection of their habitat has to be the top priority.
Nearly two hundred people attended the three-day conference, which was held in Port Macquarie in the eastern state of New South Wales.
The event was entitled “Their Future is in our Hands” and was organised by the Port Macquarie Koala Hospital, with the backing of the local council.
The conference brought together a wide range of delegates, including carers, campaigners, scientists, and veterinarians.
The founder of Queensland Koala Crusaders, Meghan Halverson, said that combining efforts and resources was the only way to win the war to save the koala. “And a war it is,” she said.
At the last koala conference in 2013, Halverson’s message was “while we are talking they are dying”.
Four years later, everyone is working harder and more collaboratively, Halverson says, “but we are still talking and they are still dying”.
Halverson (pictured below) says that, in Queensland, one million hectares of land have been cleared of native vegetation. “Of this, the WWF estimates that at least 84,000 hectares are in critical koala habitat.”
Koala carer Wanda Grabowski, who is the president and secretary of Koala Action Inc. (KAI), based in Queensland, told Changing Times: “Whatever remains of mature habitat has to be maintained, and improved when necessary. You cannot cut down any more trees in koala habitat; end of story.”
Wanda Grabowski with Burman. (Photo by Megan Slade.)
In 2015, the Australian government listed the koala as vulnerable to extinction throughout Queensland. Previously the listing had only applied to the southeast of the state.
The New South Wales and Australian Capital Territory koala populations are also listed as vulnerable.
In late 2015, a University of Queensland report presented clear statistical evidence of dramatic declines in koala populations in southeast Queensland. That report showed that, between 1996 and 2014, koala densities declined by about 80 percent in the Koala Coast area and 54 percent in Pine Rivers.
“There was some evidence to suggest the rate of decline had actually accelerated,” the report stated.
Stephen Phillips, who is an ecologist specialising in the koala, told conference delegates: “Looking at this animal throughout its geographic range in Australia, we find that there are some populations that are just on the edge, that are just about to become locally extinct; we find some populations that are stable, and we have even found some populations that are recovering.
“When you put all that information together, overall the trend is one of decline.”
Phillips (pictured left) says that the state forests in New South Wales have been harvested to within an inch of their ecological lives.
Researchers, he says, are going into forested areas that they know used to have koalas in them, and are often coming back without seeing any.
When European settlers first arrived in Australia, there were ten million koalas in the wild. There are now a few hundred thousand at most. A senate inquiry in 2011 was told that there are probably between 50,000 and 100,000.
Over the past twenty years, koala numbers have dropped by 40 percent in Queensland and by a third in New South Wales. In the Pilliga Forest of northwest New South Wales, three-quarters of the koala population has been wiped out since 2000.
Local and federal governments still do very little to protect the animal that tourists flock to cuddle.
On the first day of the Port Macquarie conference, there were protests over the inaction of the New South Wales government.
Left to right: Drusi Megget, Greg Hall, and Susie Russell.
Susie Russell from the North Coast Environment Council said: “The New South Wales government, while pretending to be concerned about koalas – and it’s the same with the federal government, is actually introducing policies that will see the best remaining koala habitat cleared as part of its forestry proposals,” Russell said.
Russell says the government is favouring the logging industry over the protection of Australia’s unique and extremely biodiverse forests.
“Land clearing legislation allows landholders to self-assess their conservation value, so we are seeing systematic government policies driving koalas and all the other species that are endangered towards extinction.”
Koalas have a home range and a pattern to their behaviour, Russell says. “If you take out the trees from their home range, they have got no home; they become stressed and they become sick.
“They move around, and they’re likely to be attacked by dogs and hit by cars.”
Koala hit by a car. Photo by Charlie Lewis.
Wanda Grabowski says the highest densities of koalas in Queensland are on the coast and this is where there is the highest pressure from urban and peri-urban residential development.
“So you’ve got humans competing for the same habitat that koalas want, and the humans are always going to win.”
Grabowski says ways need to be found to connect national parkland, reserves, open spaces, and urban parks.
“By incorporating this connectivity with remaining koala habitat, the retained, rehabilitated, and replanted koala habitat could support adult populations.”
Grabowski says that sub-adult koalas leaving their mothers are having to move through high-density residential developments to find a home range of their own, and they are not going to survive the journey.
“We already know from medical records that, in breeding season, the big, healthy males and dispersing sub-adults get hit by cars and attacked by dogs,” she told Changing Times.
Displaced koalas and other wildlife are moving into the last remaining parks and reserve land within the urban footprint, Grabowski says, and they are putting additional pressure on the residential populations there.
“Females can often share similar home ranges, but there are limits to the carrying capacity of what remains, so sub-adult females may also be forced out.”
The Queensland government will continue to permit clearing for urban development and for infrastructure, mining, and agriculture, Grabowski says.
“There are people in charge of managing the environment who have a vested interest in seeing that development continues at an escalating rate. There is clearly a conflict of interest. It’s like putting Dracula in charge of the blood bank.”
The effects of climate change
Several of the speakers at Port Macquarie spoke about the effects of climate change on koalas.
In her presentation entitled “Up the gum tree without a paddle”, ecologist from the Port Macquarie-Hastings council Rebecca Montague-Drake said that climate change was likely to have severe impacts on the animals.
An increasing number of wildfires, she said, would lead to direct mortality and habitat loss.
“Drought leads to reduced leaf water content, which will leave koalas vulnerable to hotter conditions. It will also reduce the canopy,” she told delegates.
Koalas eat mainly eucalyptus leaves, and only from certain species of gum tree.
Montague-Drake (pictured left) said that koala populations along the eastern seaboard, particularly in New South Wales and Queensland, were in great peril, and many of them were on “a steady downward run to extinction”.
The koala, Montague-Drake says, “is an arboreal marsupial that cannot go into torpor, fly, or shelter in hollows, leaving it vulnerable to weather extremes”.
She told delegates about modelling done in the Port Macquarie-Hastings local government area that she said revealed a new and hitherto unreported impact of climate change on koala populations.
Researchers conducted modelling of climate-induced rises in sea level, looking mainly at the spring tide scenario.
“The results revealed that, even under mild climate change scenarios, many areas of primary koala habitat will experience tidal inundation on a monthly (spring tide) basis,” Montague-Drake said.
“This tidal inundation will increase soil salinity levels and increase shallow ground water tables.”
This, Montague-Drake says, will be likely to reduce the survival of koala food trees such as Swamp Mahogany, Tallowwood, and Forest Red Gum.
“Even presuming that trees are able to survive such incursions, even small rises in salinity will likely impact nutrient uptake by eucalyptus species.”
Any changes in salinity levels in eucalyptus leaves will almost certainly affect the delicate balance of nutrients versus toxins in those leaves, Montague-Drake says. Salinity also suppresses plant height and the trees’ biomass.
“As a result, koalas may no longer be able to meet their nutritional demands, resulting in malnutrition and starvation.
“Such physiological stresses will also leave koalas more vulnerable to diseases such as chlamydia and the koala retrovirus.”
The researchers found that a third of all koala habitat on the coastal flood plain would be inundated within one hundred years. Across all koala habitat, 14 percent would be lost within fifty years, and 22 percent within one hundred years.
In coastal swamp forests in the Port Macquarie-Hastings area, 100 percent of the canopy often comprises koala food trees, Montague-Drake says. These forests, she says, are the environment that support the highest level of koala activity.
Montague-Drake is concerned that the 2013 modelling may already be out of date and the loss of koala habitat could reach 40 percent in one hundred years.
“A study that has come out of the US this week shows that we’re outstripping the rates of sea level rise that were expected.”
There are more immediate threats to koalas, Montague-Drake says, but unless there are major turnarounds within the next five years, “we are really heading on that track to functional extinction within fifty years, and that’s a very sobering thought”.
Ben Moore (pictured left), from the Hawkesbury Institute for the Environment at the University of Western Sydney, told Changing Times that numerous climate change factors will affect koalas.
“None of them individually is going to wipe out the koala, but a lot of them together certainly affect the way populations are able to grow after they take a hit.
“We see periods of drought and heatwaves and El Niño events and they are going to get more extreme and koala populations are going to take a bigger hit.”
We can expect shorter intervals between extreme climate events, Moore says, and the koala populations will have less time to recover.
Many koalas are killed directly by heat stress, Moore says.
It’s not clear what temperature koalas can no longer tolerate, but flying foxes die when the mercury hits 42 degrees.
When temperatures are very high, koalas go to the ground and find hollows, but they can’t take too many days of that, Moore says.
When animals are heat-stressed, Moore says, their liver becomes less able to cope with toxins in their food.
“What that means for koalas is the more time they spend heat-stressed then they’ll be less tolerant of toxic plant foods.
“That probably doesn’t mean that koalas will be poisoned, but it would narrow down their choices of leaf that they can eat.”
This would be particularly difficult for koalas in more marginal habitats where the leaf quality is already not the best, Moore says.
Scientists from the Hawkesbury Institute are carrying out extensive research into the effects of rapidly rising atmospheric carbon dioxide levels on Australia’s native forests, animals, soils, and grasses.
The EucFACE Free-Air Carbon dioxide Enrichment experiment, which has been running for four years, is exposing large areas of native Cumberland Plain eucalyptus forest to elevated CO2 at about 550ppm, which is what scientists expect will be reached by 2050, and aims to predict the effects such CO2 levels would have on ecosystems.
Increased CO2 in the atmosphere affects how plants grow, Moore says.
“The general response of plants is that we see a decrease in nutritional quality. There would be less protein in a leaf, and more fibre. But it seems that eucalypts haven’t generally decreased their protein. The toxin content is unpredictable, but tannins usually go up with climate change.”
The general effects of climate change on the nutritional content of eucalyptus leaves may not be as bad as scientists thought they might be, Moore says, “but it is going to vary from ecosystem to ecosystem”.
In the EucFACE experiment, the scientists expected the trees to grow faster, Moore says, but they didn’t, most likely because they are limited by the amount of phosphorous in the soil.
Moore says that koalas usually get all the water they need from the leaves that they eat, but when the leaf water content decreases, and it’s hot as well, they need more water and there is less water available. “That’s when they run into trouble if there’s no free water available for them.”
Researchers from the University of Sydney have been looking at how much koalas need free water, and whether this is a way of combatting some of the effects of extreme climate events.
In a study in Gunnedah in northwestern New South Wales, they have been supplementing water in the environment and have been trying to gauge the effect.
A landholder, Rob Frend, on whose farm the research is being carried out, has designed “blinky drinkers” (named after the fictional character Blinky Bill) that refill automatically.
It seems that the koalas’ behaviour is changing. Researchers found that there were 386 koala visits to each “blinky drinker” in a year, and the koalas drank for long periods.
Monitored during the winter, the animals were seen to be drinking from the artificial water stations day and night for an average of more than ten minutes.
Valentina Mella, who is leading the study, says the koalas not only drank in the tree tops, but even sought out the drinkers on the ground during the day, when they would normally be asleep.
Scientific literature is filled with statements saying that koalas do not need to drink free water, but the Gunnedah results show that koalas could benefit from water supplementation, Mella says.
In a heatwave in 2009, about 25 percent of Gunnedah’s koala population died over just a few days.
Mathew Crowther, from the School of Life and Environmental Sciences at the University of Sydney, said that, in the 2009 heatwave, when temperatures were over 40 degrees Celsius for more than a week, koalas were found dead or dying at the base of the trees.
Crowther says that examination of changes in koala occupancy on the Liverpool Plains surrounding Gunnedah, as indicated by the number of trees with koala scats, shows a 16 to 30 percent reduction from 2011 to 2015.
Crowther (pictured left) says that the population of koalas is declining on the Liverpool Plains because they are not having enough young.
He adds, however: “Overall, what seems to be driving the decline, and what will be driving the decline into the future on the Liverpool plains is climate.”
Researchers have been examining whether koalas are having to seek out different trees when temperatures increase.
“When it gets hotter they move into lower elevations,” Crowther said. “They get down into the gullies. And they tend to use many more non-food trees. The non-eucalypts tend to have higher cover, so they use these to keep cool. They need to go to taller, bigger trees.”
Tree planting is important, Crowther says, but the areas that have shown the biggest decline in the koala population are those that don’t have many old trees.
“If you are going to conserve koalas in an area, you need a wide variety of trees, not just food trees.”
The principal project officer for the Saving Our Species programme run by the New South Wales Office of Environment and Heritage, Mike Roache, told delegates that the koala population in the Blue Mountains west of Sydney appeared to be increasing, and the area was expected to become a significant climate refuge for the animals.
Climate change and disease
Associate professor of veterinary pathology at the University of Sydney, Mark Krockenberger, says that scientists researching in Gunnedah have observed a link between the occurrence of disease and climatic events.
Populations had been increasing in the area, he says, but the heatwaves in 2008, 2009, and 2010 had an impact on the local koala population.
“The population was under stress,” Krockenberger said. “All of a sudden, we went from a very low prevalence of chlamydiosis to a high prevalence.”
The prevalence increased in 2011, Krockenberger says, and, by 2015/2016, the prevalence of the disease was very high. There was a dramatic increase.
Blue gum plantations
Conference delegates heard about the plight of koalas living on blue gum plantations.
“Koalas have moved into these plantations and have thrived,” said Tracey Wilson from Mosswood Wildlife Rescue & Rehabilitation in southwest Victoria.
“However, the impact on the landscape and the koalas when these plantations are harvested is devastating.”
Wilson (pictured left) says that displaced koalas are putting massive pressure on the small amount of existing roadside vegetation, private land, indigenous land, and parks and reserves.
She told delegates that koalas are now eating coppice (the stumps that are left after harvesting).
“We have reduced these arboreal animals to grazing like sheep,” she said.
When there are bushfires, koalas will eat coppice, but they don’t usually come to the ground to feed. Wilson is therefore surprised and intrigued to see them eating coppice on the blue gum plantations.
“When I try to feed coppice blue gum to koalas in care, they will not touch it,” she told Changing Times. “The sight of a koala grazing is not good; they are arboreal animals.
“When we see a koala on the ground, it’s not right – unless they are moving from tree to tree. Why are they selectively grazing on stumps when they can go and get in a manna gum or blue gum tree?”
In 2013, the blue gum industry in the Green Triangle was exposed for killing and maiming koalas during harvesting, Wilson says. After this, a koala zone was created, and there are now koala spotters on the plantations within that zone.
New regulations are coming into force, and they will bring major improvements, Wilson says. It will, for instance, be compulsory for the companies to have koala spotters on site when burning is carried out.
Wilson still, however, wants blue gum companies to provide permanent koala habitat and the government has not yet made this obligatory.
There are more exports of hardwood chip from southwest Victoria than anywhere else in the world.
Woodchip from the blue gums is exported for paper production, and Japan and China are the main buyers.
Wood chips piled up on the wharf in Portland Harbour, waiting for export.
Ruth Lewis, who is the president of the Ipswich Koala Protection Society, told delegates that Ipswich is home to possibly the largest healthy population of koalas left in southeast Queensland, but there are areas where the animals are already functionally extinct.
Lewis talked about the Ipswich society’s most significant win, which was instigating the state government’s realignment of 12 kilometres of the southern freight rail corridor, which would have cut a path through the middle of core koala habitat.
She also spoke about the conservation efforts of the local council and said she hoped other councils would follow Ipswich’s example.
“Ipswich city council has purchased approximately 6,500 hectares of eucalypt and other native forest for the purpose of conservation and to provide safe haven for koalas and other species.
“Council, in partnership with Powerlink¹, and SEQ Catchments², planted close to 12,500 trees over 27 hectares, not only establishing critical koala habitat, but also helping build the resilience of our natural environment in the face of climate change and development pressures.”
There have also been council initiatives to establish a koala conservation agreement, a land-for-wildlife programme, and a nature refuge programme.
Over the twenty years since the protection society was set up, volunteers have planted more than a thousand koala food trees and had a purpose-built education trail made. They have carried out more than 3,500 rescues, and more than two hundred orphan koalas have been released to the wild. The society has established a dedicated rescue and rehabilitation centre and is working on acquiring a facility to establish a koala education centre in partnership with Ipswich city council.
Ipswich council has supplied the society with a thermal imaging camera to help in koala detection.
Joe Stammers from the Wingecarribee Shire Council also raised spirits with the story of the Southern Highlands Koala Conservation Project, which was established in 2014 as a partnership between the New South Wales Office of Environment and Heritage (OEH) and Wingecarribee Shire Council.
In March this year, the OEH announced that the koala population in the Southern Highlands had reached more than 3,000 and was now the largest population in southern New South Wales.
The project team is currently mapping corridors that koalas use to move around the Southern Highlands and is creating a map of land across the shire that is of high environmental value land.
Stammers said that community awareness had soared from zero to a level where not only the community, but also local councils, were supporting conservation.
One of the rare examples of koala-focused urban development is the Koala Beach Estate near Pottsville in the Northern Rivers region of New South Wales.
The residential development is designed to be totally koala friendly; residents are, for instance, not allowed to have domestic dogs.
As a result, there is a significant koala population and the development forms part of the largest relatively intact area of remaining koala habitat on the Tweed Coast.
The Australian Koala Foundation worked with the Ray Group to design the development in the 1990s and, on the 365-hectare site, more than 270 hectares of bushland was reserved for nature conservation.
There is a Koala Plan of Management, which incorporates such measures as the retention of preferred koala habitat, habitat restoration, slow traffic speeds and vehicle calming, streetscape koala tree plantings, ongoing monitoring, an environmental levy on residents, and active community involvement via a Wildlife and Habitat Management Committee chaired by the Tweed Shire Council.
A koala monitoring programme was designed for the Koala Beach Estate to detect changes and trends in the distribution and status of the koala population and to help gauge the success of the conservation measures.
John Callaghan from Biolink Ecological Consultants says there has been a decline in koala sightings at Koala Beach and the population has decreased over the past twenty years.
He says, however, that, despite downward trends in koala activity, the ongoing persistence of koalas on the estate, coupled with positive indications from a number of the Spot Assessment Technique (SAT) sites during the most recent surveys, present hopeful signs for the Koala Beach koalas in the context of broader declines in the Tweed Coast koala population.
Callaghan says the estate is still a valuable model for other councils and the development industry.
“There are many positive signs, including the fact that there are still breeding koalas at the estate,” Callaghan said. “The population is still quite widespread so, whereas there have been significant reductions in the extent of occupancy across the Tweed Coast area, that hasn’t been mirrored in the Koala Beach Estate.
There are very hopeful signs of a recovery of the koala population, particularly around the residential area, Callaghan says. “Without that population, I think the Tweed Coast koala population would be in much more dire circumstances than it is now.”
Koalas in Queensland
Wanda Grabowski says research suggests that koalas in Central Queensland are now heading towards the east because of the marginal conditions out west, poor quality habitat, and climatic conditions such as drought.
People on the coast are forcing the eastern koala population towards the west, but the mountains form a natural barrier preventing any further dispersal.
Environmental laws in Queensland state that rescuers and carers have to release koalas back into bushland within five kilometres of the rescue site, even if they know that the area will be developed in the near future.
To ensure the sustainability of the next koala generation, it may be necessary, Grabowski says, to translocate sub-adults who don’t yet have a home range of their own into areas that are protected from development, such as water-catchment land and reserves.
“Sometimes even mining or quarry land can be rehabilitated sufficiently to support koalas and other native wildlife into the future.”
Koala Action, Moreton Bay Koala Rescue, and Queensland Koala Crusaders are urging local councils and state and federal governments to facilitate a change in legislation to enable translocation to areas outside the five-kilometre demarcation line.
Such translocations would only be carried out as an emergency measure if all habitat at a particular site was going to be razed to the ground, Grabowski says. “It will be undertaken to ensure the survival of koalas in a specific area only when no other options are available. It has to be done with careful thought, and management strategies should be incorporated into the plan.”
Tree species and soil profiles need to be similar, Grabowski says, and the koalas being translocated must be in excellent health.
“The koalas already in the area also get health checks, and both populations must be monitored to determine whether there are any negative impacts.
“If both populations remain viable and produce young, this would indicate a successful translocation.”
Grabowski says that, if the Queensland government’s approach doesn’t change, the picture is bleak. “However, if enough people speak out about protecting the koala and conserving the habitat on which it depends then legislation will change and councils can be encouraged to turn the situation around.”
If the status quo remains, the Queensland koala population will continue to decline, Grabowski says.
“Positive action has to be taken at all levels of government, and in local councils, and only then will the decline at least stabilise.”
At the Amcor Petrie³ site, where the new campus of the Sunshine Coast University is going to be built, the koala population is actually increasing.
“It’s the only site in the Moreton Bay region where the population is increasing; and why? Because there is still habitat there.
“If we can retain koala habitat and build up wildlife corridors that are at least 100 metres wide, I have no doubt that we can make a difference and ensure the survival of Queensland’s faunal emblem.”
People need to write letters and emails, Grabowski says. “They need to telephone, and try to meet, their divisional councillors and state representatives, and urge them to do something about retaining remaining koala habitat and rehabilitating secondary habitat.”
Creating sanctuaries is another option, Grabowski says. “They would have to be fenced, to keep out feral animals.”
Such sanctuaries could house animals that are currently being euthanised because they cannot be released back into the wild.
Grabowski prefers to use the word “killed”. She says that, aside from having minor injuries, or not being reproductively viable, the animals are otherwise healthy.
“Koalas are being ‘euthanised’ because they cannot breed, have lost a digit or paw, have one ear missing, or are blind. In a safe, bushland environment these koalas can still be cared for to ensure that they remain healthy and live out their natural lives doing the things they have always done.
“Why can’t we let those animals live in a natural setting and give people the opportunity to come and see them?”
The income from visitors could then be used to buy more land, Grabowski says. “The local councils could help finance tree plantations that would be used to feed koalas in the sanctuaries.”
The story of the koalas in Moreton Bay in Queensland is two-edged. A very successful large-scale monitoring programme took place while work was being carried out on the Moreton Bay rail link (now called the Redcliffe Peninsula Line), which runs through some of the last intact urban and peri-urban bushland in the region and was opened in October last year.
However, a total of 292 koalas died during the monitoring period (from March 2013 to June 2016). Of these, 116 were killed by wild dogs, 82 died from illness, 19 were killed by carpet pythons, and nine were hit by cars. One died from bee stings after disturbing a hive.
“It wasn’t until we urged Moreton Bay regional council to intensify its wild dog management at this location that we actually halted the decline,” says Wanda Grabowski.
“The majority of the kills were not torn apart, some were eaten and the rest were stored, by burying, to be consumed later which is typical wild dog behaviour.
“One dog was responsible for more than 80 percent of the kills and he did it for pleasure. Nothing was eaten; the koalas were just chased, caught, and mauled and died of their injuries and shock.”
Deidré de Villiers (pictured left) from the Queensland company Endeavour Veterinary Ecology told delegates in Port Macquarie about the Moreton Bay Rail Koala Tagging and Monitoring Programme.
The programme began ten months prior to the start of vegetation clearing and construction. It was implemented to minimise the risk of death or injury to koalas during construction works, to provide scientific data to inform and support mitigation measures, and to offset some of the residual impacts of the rail project on the koala population.
“One of the key aims of the project was that no koalas were killed during the vegetation clearing or construction work and we achieved that,” De Villiers said.
More than five hundred koalas were captured and given veterinary examinations and most were fitted with custom-designed telemetry devices and were monitored in the wild.
“Disease management, translocation, wild dog control, habitat offsets, and fauna crossing structures were key components of the management programme,” De Villiers explained.
“At the peak time, we had a koala dying from a wild dog attack every second day, which is devastating,” she said.
The Moreton Bay monitoring has provided a large number of samples that other scientists have been able to use in their koala studies and the first successful field trial of a vaccine against chlamydia in koalas was carried out at Moreton Bay in 2014.
Stephen Phillips told delegates about the koala population in Port Stephens, which is one of the largest coastal koala populations in New South Wales and has been a hub of research about koalas for nearly thirty years.
The population was nearly lost in a fire in 1994, but it did recover.
“When we go to the most recent three koala generations there has been some quite dramatic change,” Phillips said. Populations had disappeared from several areas and there was a reduced occupation in several others.
“The areas of generational persistence have reduced by approximately 40 percent in the last three koala generations. When you get to 50 percent you’re endangered and about to zip off the radar.”
Phillips talked about koala hubs, or source populations, which he says are the last bastion of koala conservation.
“If you cannot conserve these, the animal is lost; it’s as simple as that.”
Phillips cites a swampy area where he thinks koalas have gathered. “If that’s correct, then we are able to guide council and hopefully government into applying and focusing conservation resources into those hub areas.
“Deal with the roads, deal with the habitat loss, and fix the fragmentation. Do it there and you’ll hold the population.
“The challenge for all of us is to work collectively to get these hubs identified.”
The koala population in the Coffs Harbour area of new South Wales has declined by 50 percent in the past 15-20 years and conservationists have called for an end to hardwood logging in the area.
The Australian Broadcasting Corporation has obtained a map that shows the area that is marked for extensive logging, and it is the area where there is the highest quality koala habitat.
One current proposal is for a Great Koala National Park that would include many of the state forests in the Coffs Harbour hinterland.
The government, however, insists that a balance has to be struck between jobs and preserving the environment.
Meghan Halverson and Josey Sharad from The International Fund for Animal Welfare (IFAW) told delegates in Port Macquarie about the work being done with koala detection dogs.
QKC and the IFAW are working in collaboration with the University of the Sunshine Coast and there are now four trained dogs detecting koalas in the “Detection Dog for Conservation” initiative.
Thanks to the dog detection, Halverson says, strides can be made to analyse larger samples of data and give a better picture of koala health and genetic distribution throughout the landscape.
Thor Aaso from the Port Macquarie-Hastings council spoke about the dog- and owner-training that is being done in an effort to reduce canine attacks on the urban koala population in Port Macquarie.
He also told delegates about a mobile GIS6-enabled data recording system that assists the staff of the Port Macquarie hospital, the local council, and researchers. It enables the capture and collation of location, clinical, and other information about koalas.
The app has helped researchers to do heat map analysis to work out where there is a high incidence of car hits.
Much of the Port Macquarie conference was taken up with reports on scientific research into the diseases that affect koalas.
Microbiologist Adam Polkinghorne from the University of the Sunshine Coast talked about the Chlamydia pecorum infections that are widespread in koala populations and also highly prevalent in Australian livestock.
Koalas are affected by two different strains of chlamydia: Chlamydia pneumoniae and Chlamydia pecorum. Chlamydia pecorum is the most prevalent and the highest rates of infection are in Queensland and northern New South Wales. Most koala populations are infected with Chlamydia pecorum, but the impacts of the infection vary.
Koala populations in Victoria have high levels of chlamydia, but there is a different disease presentation to that in Queensland or New South Wales, Polkinghorne says.
Many koalas are infected with chlamydia, and are passing it on, but don’t show actual signs of the disease.
Koalas are the least common host of Chlamydia pecorum in Australia, however; the most common hosts are sheep and cattle, with 30 to 40 percent of the sheep population shedding Chlamydia pecorum in their faeces.
Polkinghorne says there is growing evidence to suggest that koalas are being exposed to livestock Chlamydia pecorum strains and his hypothesis is that it is through environmental contamination.
He says that comparison of koala Chlamydia pecorum strains with those from livestock strains provides strong evidence that supports the hypothesis, supported by some molecular evidence, that all infections in koalas may have resulted from the introduction of livestock infected with Chlamydia pecorum to Australia.
Polkinghorne points out that the first sheep and cattle to come to Australia came from South Africa, not from Europe. “So we should be looking in South Africa for the potential origins of chlamydia.”
Some of the Chlamydia pecorum strains found in koalas are more similar to livestock strains than they are to other koala strains, Polkinghorne says.
“A continued expansion of our analysis to include historical koala Chlamydia pecorum samples and a more diverse range of overseas livestock strains is anticipated to provide more evidence to test the latter hypothesis.”
Using genome sequencing, researchers have found three examples of chlamydia livestock strains in koalas. “In a South Australian koala and in central New South Wales koalas we find strains that are virtually identical to livestock strains,” Polkinghorne said.
On the south coast of Victoria researchers found a strain that clusters with strains of Chlamydia pecorum found in European pigs.
A koala with ulcers resulting from chlamydial infection.
One new discovery, Polkinghorne says, is that koalas can be infected by more than one strain of Chlamydia pecorum at the same time.
Researchers have found that the Chlamydia pecorum strains found in koala populations in Queensland and New South Wales appear to be genetically different to the strains found in Victoria and South Australia, but Polkinghorne is not sure that this will be backed up if there is further sampling.
Polkinghorne is also involved in the chlamydia vaccine trials.
Scientists have now completed two field trials. “Both of those trials have shown that vaccinated koalas have improved infection and disease outcomes over a one-year period compared to koalas that didn’t receive the vaccine,” Polkinghorne told Changing Times. “There was a lower incidence of infection and of disease.”
The researchers are now analysing the samples to try and understand why some koalas had an improved outcome while others didn’t. “By doing that we can hopefully use that information to further refine the vaccine in preparation for some other field trials.”
The scientists are examining the potential therapeutic efficacy of the vaccine. They hope it will boost the immune response of koalas who already have chlamydial infection and be an alternative to antibiotics. “Some of the early data suggests that might be the case,” Polkinghorne said.
Delegates also heard about the work being done to develop a vaccine against the Koala retrovirus (KoRV).
Olusola Olagoke from the Faculty of Science, Health, Education and Engineering at the University of the Sunshine Coast in Queensland said the majority of Australia’s koalas are infected with KoRV.
There is a 100 percent KoRV infection rate in Queensland, Olagoke says. All Queensland koalas have the KoRV-B genome. The infection rate is less in South Australia, Olagoke says, and there is no KoRV-B, only KoRV-A.
KoRV-A was discovered in Queensland and KoRV-B was originally found in captive koalas at Los Angeles zoo, and results from a mutation of KoRV-A.
Both KoRV-A and KoRV-B have been strongly implicated in chlamydial disease, but KoRV-B has more association with lymphoma and leukaemia, Olagoke says. Some zoos have reported a koala mortality rate of up to 50 percent from these diseases.
Olagoke (pictured left) said that, in a trial in Adelaide, researchers had successfully vaccinated five koalas with a recombinant KoRV envelope protein vaccine.
Three of the koalas are KoRV-positive and two are KoRV-negative.
The animals have had no adverse responses to the vaccine, Olagoke says, and have shown a KoRV-specific immune response.
“If the koalas do develop antibodies, they should be able to clear their current infection, and reinfection should also be prevented.”
Delegates also heard about the management of oxalate nephrosis (renal disease) in koalas in a captive environment.
Melissa Pettigrew Burford from the Cleland Wildlife Park in South Australia said that 60 percent of the sixty koalas in the park, who have either been hand-raised or bred in the park, have shown clinical signs of renal disease.
“Oxalate nephrosis is quite a large problem in the Mount Lofty Ranges. We do have quite a high prevalence in the population.”
Kidney dysfunction has been shown to be prevalent in the South Australian population, Burford says, and is less frequently seen in the eastern states.
Research is ongoing into the diet, liver function, and low genetic diversity of South Australian koalas, she adds.
There are numerous theories about the possible cause of oxalate nephrosis in koalas, Burford says. Genetics is the most obvious one, she says, and diet is another. “The oxalate4 level in some of the eucalypt leaves in South Australia is a little bit higher in some species compared to that in eastern states.”
Research is also being done into whether the enzyme in the liver that should break down the oxalate is missing in the koalas.
A main sign of oxalate nephrosis is a koala spending very lengthy periods on the ground drinking excessive amounts of water, Burford says. Koalas with oxalate nephrosis will also have a dramatic and usually rapid loss in body weight.
Koalas at Cleland who have been diagnosed with oxalate nephrosis are treated with vitamin B6 and Vivitonin.
“We have had great success with this,” Burford (pictured left) told delegates. “Over the last couple of years the number of koalas that we lose to kidney disease has been quite drastically reduced.”
While the condition of most of the koalas being treated for oxalate nephrosis becomes stable under treatment, extreme hot or cold weather can cause acute renal episodes.
If koalas stop eating, they are given gum smoothie “boost juice” made of eucalypt leaves blended with a nutritional supplement.
Most of the koalas who have been diagnosed with oxalate nephrosis at Cleland are low-dependency, Burford says, and the disease is relatively easy to manage in a captive environment, but there has to be long-term, ongoing treatment.
“At the moment, this isn’t really viable for a wild koala. The stress factor alone of catching a wild koala every day to administer Vivitonin and B6 is going to be quite counteractive.
“We need to know more about oxalate nephrosis and how we can manage it in the wild, or maybe even prevent it.”
Burford also reports an increase in in the Cleland Wildlife Park of the number of koalas with Sarcoptic mange, which is caused by the Sarcoptes scabiei or itch mite.
She also spoke about koala stress syndrome. Compared to other mammals, koalas seem to have quite a different adrenal and thyroid gland structure and functioning, she explained.
“This means their ability to deal with stress is quite reduced.”
It’s therefore important when caring for koalas with oxalate nephrosis, Burford says, to manage the stress factors that could not only trigger the disease, but also accelerate it.
Burford says koalas became extinct in South Australia in the early 1900s. “They got hunted in the fur trade. Small numbers were taken from the mainland in Victoria and put on offshore islands, including French island.”
About 18 koalas were taken from French island and were released onto Kangaroo island in South Australia. A small number were later translocated to the Mount Lofty ranges just east of Adelaide. Others were taken to the Riverland and the Eyre Peninsula.
“Having effectively two genetic bottlenecks5 in a really short period of time does leave them very vulnerable and open to disease,” Burford says.
Habitat loss is also a huge issue in South Australia, she adds.
There are some areas in South Australia, like the Mount Lofty ranges and Kangaroo Island, where there is some koala overpopulation, Burford says, and koalas have done some damage to the local native environment.
There is increased koala urbanisation, she says. “A lot of these koalas are moving more and more into urban environments, so that does increase their chances of coming into contact with dogs and also cars.”
Koala population in South Australia ‘overestimated’
The koala coordinator at Fauna Rescue in South Australia, Merridy Montarello, also spoke about the high rate of oxalate nephrosis in the state.
She added that, according to recent data, the incidence of koala retrovirus (77 percent) and chlamydia (32 percent) is much higher in the South Australia koala population than previously thought.
“It is estimated that we have had up to 1,500 koala rescues and 600 have died of oxalate nephrosis.
“If this keeps happening, along with loss of habitat, road kills, dog attacks, and infectious diseases, within fifty years, we may well see the end of South Australian koalas.”
Montarello said the true size of the koala population in South Australia was unknown because of inadequate data. “We think that it is probably significantly overestimated.”
According to Montarello, the population is in significant decline. She said government funding and resources must be urgently directed into monitoring and the government must classify South Australian koalas as endangered.
“We must,” Montarello says, “learn from the disastrous effects of previous koala culls.”
Montarello was taught by a deaf child how to say “Koala in a tree” in sign language.
Another area of Australia where there has been controversial koala culling is the Otways in southwestern Victoria.
In 2013 and 2014, the authorities euthanised hundreds of koalas in the Cape Otway area, about 230 kilometres southwest of Melbourne. They said they were responding to the problems caused by the overbrowsing of manna gum trees, which stripped the trees and left many koalas starving.
There was widespread outrage when news about the culls finally came out in media reports in March 2015. Some conservationists said the problem was loss of habitat, and argued that killing koalas was not the solution. It was even suggested that there might have been disease in the gum trees themselves.
Delegates in Port Macquarie heard from Desley Whisson from Deakin University, who has done a significant amount of research at Cape Otway.
She said that in the four or five years previous to 2013, she had watched the koala population at Cape Otway increase. “In September 2013, it reached a point at which the trees could no longer sustain the browsing pressure of this population.
“Trees died. There was widespread defoliation of trees as well. And ultimately several thousand koalas died as a result of starvation. It was really devastating for me to witness this.”
For years, Whisson says, there had been appeals to the government to take action in the Otways. “They talked about it a lot and nothing happened until it was far too late.”
Whisson (pictured left) came to the Otways in 2008. “I couldn’t believe my eyes: ten koalas a hectare, in trees that didn’t appear to be in particularly bad condition.”
The koala density remained level for several years, then started to increase after 2011.
“By September 2013 we had reached a peak of 23 koalas a hectare in some sites,” Whisson said. “And then the crash started.”
The percentage of healthy trees went down from about eighty percent in 2008 to less than five percent in September 2013.
By then, hungry koalas were converging on just a few trees, Whisson says, “females with back young reaching for the very last leaf”. The animals were often resorting to peeling bark off trees and eating bracken.
Despite the horrific situation, she says, “there had been no action and no sign of action by any of the people who had the power to do something about it”.
Finally, a team of vets came in to assess the koalas’ health, Whisson says, and most of the animals were found to be healthy.
“But we had nothing we could do except give them a hormone implant and release them into trees that had pretty much no leaves left on them.”
Twenty days after the veterinary check, Whisson says, joeys were no longer with their mothers. “They had just simply disappeared.” Whisson suspects that foxes were picking up carcasses off the ground.
There was then a second veterinary check “It was pretty well over for most of the koalas that were part of my study,” Whisson said.
“More than half of them had already died. I had spent each week pretty much picking up carcasses.”
Whisson says the Otway koalas had very tight home ranges, and showed high fidelity to those ranges. “When there were no food resources left the koalas tended not to move very far. Some of them died within their home ranges.”
By January 2014, the government had enthanised about seven hundred koalas, Whisson says, “and probably more than double that had died of starvation out of sight”.
Some trees managed to survive, Whisson says, and, within two years, the local koala population had doubled again in areas that had very little leaf left to sustain them. There is extremely high fecundity in the population, Whisson says. “Eighty to ninety percent of females bearing young every year, even since this particular crash and despite the poor food sources that are in most areas.”
The government moved in again in 2015 with plans to do some translocations and some fertility control, Whisson says. Koalas were moved out in late 2015, and again in 2016.
In late May this year, about two hundred koalas were moved out of the area.
There needs, Whisson says, to be a long-term koala management plan for the Otways, with more focus on the trees, not just the koalas.
“Clearly, reactive management like this does not tend to have good outcomes.”
At Cape Otway, less than 5 percent of 450 hectares of manna gums remains, and most of those trees are in poor condition.
Koala management has to be proactive, Whisson says.
“We need to consider whole landscapes. There are parts of the state where there are declining populations, so we need a state-wide strategy.”
In response to the revelations about the Otways culls, the chief executive officer of the Australian Koala Foundation, Deborah Tabart, said the real problem was gross mismanagement of koala habitat over the past sixty years or more.
Tabart says the koalas in Cape Otway were put there more than thirty years ago for tourism purposes, and the repercussions are now obvious. She sees the issue as an underpopulation of trees, not an overpopulation of koalas.
“Koala numbers at Cape Otway are a result of gross mismanagement. The Australian government should hang its head in shame,” she said.
The koalas shouldn’t have been moved to Cape Otway, Tabart says, because the preferred trees for Victorian koalas do not grow well on the soils there.
Pam Whitely from the Faculty of Veterinary and Agricultural Sciences at University of Melbourne, told conference delegates about the health of koalas in Victoria and the work of Wildlife Health Surveillance Victoria.
Whitely who is an active member of the Australasian section of the Wildlife Disease Association, and of the Asian Society of Conservation Medicine, explained that koalas could be reservoirs of zoonotic infections, which can pass from animals to humans. Togaviridae Alphaviruses like the Ross River and Barmah Forest viruses could infect people via mosquito bites, she said.
Chlamydia pecorum is not thought to be a zoonotic, whereas Chlamydia psittaci is a threat to birds.
“When you move animals you move their diseases so translocation considerations are important,” Whitely told delegates. “Detection and surveillance are very important.”
General, scanning surveillance is the most important component of a national wildlife health programme, Whitely says. “It is the only way you can know what pathogens exist in our wildlife, and the only available form of national vigilance for emerging diseases.”
The section of the 2009-2014 national koala conservation management strategy that refers to Victoria stated that there were few places where koala populations had declined as a result of deaths from car hits, dog attacks, and habitat loss.
“The principal concern for koala management is overabundant populations and overbrowsing.” Whitely said.
In Victoria, Whitely says, most potential habitats are now occupied or have burnt in bushfires. “Sterilisation is increasingly undertaken using hormone implants, and management involves capturing and this is very expensive.”
Whitely says researchers from the veterinary faculty initially (in 2008) carried out an online syndromic surveillance survey. They received 75 reports about koala health and about 20 percent of them were about weak, thin animals, in poor condition, who were found on the ground.
There were fatalities and some had eye disease, skin changes like ulcers, or wet bottom, which is an indication of chlamydial disease.
Whitely (pictured left) says Sarcoptic mange has become a problem in koala populations at multiple sites in Victoria. “We’re not sure of the source, but it could be from mangy wombats or mangy foxes.”
Oxalate nephrosis, Whitely says, could have a genetic component.
In the case of Chlamydia pecorum, research by Alistair Legione from Melbourne University has shown that older koalas are twice as likely to be infected as younger animals and males are more likely to be infected than females.
The Chlamydia pecorum seen in koalas on French island has been found to be closely related to the one found in cattle in western Australia.
According to Legione’s findings, on average, 25 percent of koalas in Victoria are infected with retrovirus, but there were no KoRV-B infections. “There was no link between chlamydia and KoRV in these results,” Whitely said.
Koalas in Victoria have not been listed as vulnerable, but carers say there has been a dramatic decline in the populations in certain parts of the state. They say there are localised extinctions because of urbanisation, habitat fragmentation, tree-felling, fire, and climate change.
In the 1890s, there was near extinction of koalas in Victoria and it was thought to be the result of disease and hunting, Whitely explains. Of the surviving populations in east Gipsland, some were taken to French island. There was a genetic bottleneck and there were widespread translocations and a reduction in genetic diversity.
The Koala Health Hub
Damien Higgins from The University of Sydney told delegates about the Koala Health Hub.
He said that more than two hundred stakeholders now supported koala clinical care, laboratory and field research, management, and policy across four states.
“In our role as a hub we aim to bring together researchers and koala managers from across the country, so that research can better inform management, and so managers can better direct research.”
Higgins says the aim of the Koala Health Hub is to provide evidence-based support for koala care and research
It’s important, he says, to build a sustainable and accessible network of koala veterinary expertise, and provide opportunities for training veterinarians in the management of diseased koalas.
Current projects include scat-based genetic and disease studies on the New South Wales far south coast populations, field and laboratory support for the Southern Highlands koala project, and projects at Gunnedah and in the Blue Mountains.
The hub provides free chlamydial diagnostics to more than three hundred koalas in care per year and an additional 150 koalas are being actively monitored in the wild.
Mark Krockenberger is a steering committee member of the Koala Health Hub and is involved in a major project in which researchers are examining the intersection between ecology and disease in the Gunnedah region.
Krockenberger spoke to delegates about cryptococcosis, a potentially fatal fungal disease that is quite common among captive animals. The fungus is found in tree hollows, particularly in eucalypts.
Cryptococcosis is a sporadic problem in wild animals that is probably underestimated, Krockenberger says.
One of Krockenberger’s PH students has been looking at the effect of eucalypt toxins on the koala’s immune system, including whether they might affect the animal’s capacity to combat disease.
Eucalyptus leaves are poisonous to most animals and humans, but the koala’s digestive system is especially adapted to detoxify the poisonous chemicals in the leaves.
In a counterbalance to the mass of scientific data presented at the Port Macquarie conference, Steve Garlick, who is an honorary professor in the Centre for Compassionate Conservation at the University of Technology in Sydney, spoke about the emotional lives and behaviours of wild animals.
“Engaging with the emotional side of wildlife can tell us how to construct a care situation enabling effective recovery of the sick and injured wild animal in conjunction with the usual provision of medication, veterinary surgery, and pathology analysis, Garlick said.
Garlick, who founded the Australian Animal Justice Party, has been rescuing, treating, and rehabilitating wildlife for 17 years and, with his wife, Rosemary Austen, runs the Possumwood Wildlife recovery and research centre in the southern tablelands of New South Wales.
Garlick talked about trans-species learning. There are knowledge systems in wild animals, he says, “and they could be very helpful for us in better understanding the recovery needs that they have”.
Before you start to gather knowledge from wild animals, however, you need to start from an ethical, teacher-teacher perspective, Garlick says.
Accessing wildlife knowledge systems can help us find answers when dealing with important environmental issues like sustainability, habitat pressure and climate change, he adds.
Garlick also talked about post-traumatic stress disorder in wild animals. He spoke about animals he has cared for who were inconsolable. “They were just climbing the walls. You could not do anything with them.”
When caring for animals, Garlick says, it’s not enough just to look at the physical animal.
“You have to look at the emotional animal and, when looking at the emotional animal, you get a whole swag of new information.”
Koalas feeding on tree bark
James Fitzgerald (pictured left) showed delegates at Port Macquarie fascinating footage of koalas feeding on the bark of a koala chew tree at his wildlife sanctuary in the Snowy Monaro region of New South Wales and explained that koalas are drawn to the bark because of its high sodium content.
Most Eucalyptus mannifera trees are not targeted by koalas as they don’t have sodium in the bark, Fitzgerald says, but a small number of eucalyptus trees have between 900 and 2,000 milligrams of sodium per kilogramme of bark.
“The koalas find these trees and eat the bark to get the sodium. We believe that the Eucalyptus mannifera trees that contain the sodium in their bark have a rock deposit in the ground under the tree that is high in sodium.”
The discovery by conservationist Garth Dixon that koalas were eating the bark from specific Eucalyptus mannifera trees led to follow-up work by Chris Allen from the National Parks Wildlife Service and research by Jessie Au, a PhD student at the Australian National University.
Chris Allen set up motion detection cameras at six ”chew trees” on the Black Ridge conservation property, and captured evidence of koalas eating bark, and both Allen and Fitzgerald provided Jessie Au with GPS data about chew tree locations.
Jessie Au looked at how intensively koalas were chewing bark and found that this ranged from little “test chews” to evidence that some trees had been heavily chewed for years.
Samples of bark and leaf samples were taken from trees at three locations. Jessie Au examined samples from chewed trees, nearby Eucalyptus mannifera trees that were not chewed, and nearby non-mannifera eucalyptus trees and established that the koala chew trees had higher levels of sodium in their bark than the others.
Fitzgerald says that it is very important to protect the chew trees from such damage as hazard reduction7 burns.
“We need to survey areas prior to hazard reduction burning, find the koala chew trees, and rake around the base of the trees to prevent them from being burnt.”
The 2015 University of Queensland report prompted a review of koala conservation policies by the Queensland government and the establishment of a Koala Expert Panel to review existing measures and make recommendations about the most appropriate and realistic actions that could be taken to reverse the decline in koala population sizes and ensure the long-term persistence of koala populations in the wild in southeast Queensland. The panel produced its interim report in February this year.
There was public consultation between September and November 2016, which indicated that loss of koala habitat was considered to be the threat having the greatest impact on koalas, and that urban development was considered to be the primary cause of habitat loss.
The 2015 report said that the decline in koala populations in southeast Queensland was related to ongoing habitat loss resulting from increasing urbanisation, other threats such as dog attacks and road mortality associated with development, and disease.
A koala being fed at the Port Macquarie hospital, New South Wales.
Calls for action
Phil Spark from the Northwest Ecological Services in New South Wales, asked delegates in Port Macquarie to contribute to a joint statement about new proposed legislation about clearing vegetation – the 2016 Biodiversity Conservation Bill.
The public are currently able to make submissions about the codes of practice that will regulate clearing in New South Wales.
“In our region, river red gums and brittle box have been listed as invasive species,” Spark said. We have huge problems with overcleared landscapes, particularly the flood plains.”
Spark cited one area, Croppa Creek, where koala habitat is being illegally cleared. “Under the new codes, that is likely to continue, except that it’ll become legal.”
There is a conflict, Spark says, between the New South Wales koala strategy and the new vegetation clearing regulations.
“The codes will be undoing a lot of what the koala strategy is supposed to be achieving.”
While the main issues at the 2017 koala conference were the same as at the previous conference in 2013, delegates did learn about inroads into medical techniques and new survey techniques and methodologies that are providing more accurate information about koalas.
“The science is certainly getting better,” Wanda Grabowski said. “We are finding options that will ensure that koalas are healthier and that a greater number of the population breed, all of which is a good thing.
“However, if we cannot save the habitat, then we won’t have any place to put these animals once they have been rehabilitated.
“There are a lot of positives, but, if some core elements are not changed, it may be too little too late. More actions need to be implemented; not words, not papers, not management plans, not recommendations; on-the-ground actions.
“Only then can we guarantee a future for koalas in Queensland and throughout their natural range.”
Photo courtesy of Queensland Koala Crusaders.
- Powerlink Queensland is an electricity transmission system operator owned by the Queensland government.
- SEQ Catchments is a community-based, not-for-profit organisation that works to protect and restore the natural resources of southeast Queensland.
- The former site of the Amcor paper mill.
- Oxalate is a naturally occurring molecule found in abundance in plants and humans. Too much can lead to kidney stones.
- A genetic bottleneck is a sharp reduction in the size of a population as a result of environmental events or human activities. Such events can reduce the variation in the gene pool of a population and, thereafter, a smaller population, with a correspondingly smaller genetic diversity, remains to pass on genes to future generations.
- Geographic Information System
- Hazard reduction is aimed at reducing the effect of bushfires. It includes controlled burning, mechanical clearing such as slashing undergrowth, and reducing ground fuel by hand.
Felled pine forest near Bathurst, Queensland. Photo by Louise O’Brien.
Send a KIMBY to Queensland politicians.
Article updated on 18/06/2017.
SUPPORTING CHANGING TIMES
YOU CAN SUPPORT MY WORK VIA THE PAYPAL OR GOCARDLESS BUTTONS ON THE TOP RIGHT-HAND SIDE OF THIS PAGE. DONATIONS AND PAID SUBSCRIPTIONS KEEP THIS WEBSITE GOING. THANKS.