A koala’s home is much more than one gum tree.
It is a living neighbourhood made up of food trees, resting trees, shade trees and safe pathways between them.
When those trees are cleared, a koala does not simply move into the next forest. It may have to cross a road, enter a backyard with dogs, travel across open ground or compete with other koalas for the few trees left.
A line of disconnected trees is not the same as a healthy forest.
Across Queensland, New South Wales, the Australian Capital Territory, Victoria and South Australia, koala habitat is being lost, broken into smaller pieces or damaged.
The problem is not exactly the same everywhere. In Queensland and New South Wales, clearing and development are major dangers. In parts of Victoria and South Australia, some koala populations are crowded into limited habitat and can overeat their favourite trees. Fire, drought, heat, disease and plantation harvesting add even more pressure.
Planting trees is essential, but it cannot be used as an excuse to destroy mature habitat today.
A seedling is a promise for the future. A mature tree is a koala home right now.
What Makes a Tree Good Koala Habitat?
Koalas have been recorded using more than 120 species of Eucalyptus, Corymbia and Angophora across Australia.
They may also use paperbarks, brush boxes, she-oaks and other trees for shelter or occasional food. However, koalas do not eat every gum tree, and they do not use the same tree species everywhere.
Their choices depend on:
- the local climate and rainfall;
- the type and condition of the soil;
- how much moisture is in the leaves;
- the natural chemicals in the leaves;
- the size of the tree; and
- whether other useful trees are nearby.
Even two trees of the same species can have different food value. Koalas often choose larger trees and trees growing close to other suitable feeding and shelter trees.
Healthy koala habitat therefore needs a mixture of locally suitable trees. It should contain food trees with nutritious leaves, large trees with strong branches, dense shade trees for hot days and younger trees that will eventually replace older ones.
Most importantly, those trees must be connected. Koalas need to move between feeding areas without spending long periods on the ground.
This is why a row of newly planted seedlings cannot immediately replace an established woodland.
The 40-to-50-Year Problem
It is sometimes said that a tree planted today will not be strong enough to hold an adult koala for at least 40 or 50 years.
The full truth is a little more complicated.
Some fast-growing eucalypts may be climbed or browsed by koalas within about three to five years, especially when koalas already live nearby. Young trees can produce fresh leaves and become useful surprisingly quickly.
However, this does not make them equal to mature habitat trees.
A forest red gum, for example, may take roughly 20 to 50 years to reach its mature height, depending on rainfall, soil, access to water and other growing conditions. During those decades, it develops:
- a thicker trunk;
- stronger and wider branches;
- a larger canopy;
- more leaves;
- safer resting places; and
- better protection from heat and weather.
Koalas may use young trees for feeding, but they generally prefer mature trees when those trees are available because mature trees provide more leaves, canopy and shelter.
The important message is therefore still true:
A sapling planted today is not a like-for-like replacement for a mature tree removed today.
It can take at least 40 to 50 years—and sometimes longer—for a planted tree to develop near the strength, branches, canopy and dependable leaf supply of mature habitat.
We must keep planting for tomorrow, but first we must protect the habitat koalas can use today.
Koala Habitat Trees by State and Territory
The trees listed below are examples, however not a planting guide for every property.
The correct species can change within a state from one council area, soil type, climate zone or regional ecosystem to another. Always obtain local ecological advice before planting.
Queensland
Queensland stretches from tropical Cape York to dry inland country and the cooler south-east. Because of these great differences, Queensland’s koalas use many different trees.
Important koala trees in Southeast Queensland include:
- Queensland blue gum or forest red gum;
- tallowwood;
- swamp mahogany;
- Sydney blue gum;
- flooded gum;
- small-fruited grey gum;
- spotted gum;
- narrow-leaved ironbark;
- grey ironbark;
- brush box; and
- broad-leaved paperbark.
In south-western Queensland, river red gum, poplar box, mountain yapunya and other dry-country trees can be important. White cypress can also provide shelter, even though it is not a major food tree.
Southeast Queensland is one of Australia’s greatest koala-habitat battlegrounds.
Rapid population growth, roads, housing and infrastructure have removed and divided large areas of woodland. Much of the essential habitat that remains is located on private land. Clearing also forces koalas towards roads, dogs and stressful journeys across open ground.
Queensland has rules intended to protect mapped core koala habitat in priority areas. However, a map cannot save a tree by itself it requires human action, and the choice not to destroy but to preserve.
Habitat outside mapped areas, individual mature trees and the corridors connecting larger habitat patches can also be extremely important.
New South Wales
New South Wales has one of Australia’s most detailed systems for identifying regional koala trees.
The state is divided into koala management areas because a tree that is important on the North Coast may be less useful on the western plains.
Common examples of important New South Wales koala trees include:
- tallowwood;
- forest red gum;
- swamp mahogany;
- Parramatta red gum;
- ribbon gum; and
- cabbage gum.
Inland and western koalas may rely on river red gum, coolabah, bimble box, yellow box, white box and western grey box. Grey gums, stringybarks and other species can also be valuable in particular districts.
A statewide review found evidence of koalas using 137 different tree species. This was later refined to 123 species for the Koala Habitat Information Base.
That large number demonstrates why there cannot be one simple national list of “koala trees.” Local conditions matter.
New South Wales habitat has been heavily cleared and fragmented, particularly on fertile land that is also attractive for farming and development.
Bushfires, logging, roads, urban growth, drought and extreme heat add to the damage.
Importantly, the official New South Wales restoration guidelines say the first principle of restoration is to protect existing habitat—even when that habitat consists of individual mature trees.
Restoration should then repair damaged areas, enlarge surviving habitat and connect separated patches.
Australian Capital Territory
The ACT sits near the edge of the koala’s natural range.
Koalas were once reported in the district, but clearing of lowland woodland for farming and development greatly reduced their habitat.
Current ACT conservation advice says wild koalas are now extremely rare. Surveys conducted in 2018 did not detect any wild koalas, although authorities cannot rule out the possibility that a small number remain.
Locally important koala trees identified for Ngunnawal Country and surrounding areas include:
- ribbon or manna gum;
- brittle gum;
- snow gum;
- broad-leaved peppermint;
- black sallee;
- grey gum;
- red stringybark; and
- scribbly gum.
The ACT provides a serious warning.
Waiting until an animal has almost disappeared makes recovery much harder. Protecting and reconnecting suitable woodland, creek lines and wildlife corridors is necessary before a secure wild population can return.
Victoria
Victoria has a large overall koala population, but this does not mean every Victorian population or habitat area is safe.
Manna gum and swamp gum are especially important in some southern and coastal areas. Other locally used trees include coastal manna gum, blue gum, river red gum, messmate, stringybarks, grey box, yellow box and red box.
The correct tree mixture changes between Victorian regions.
Victoria faces two very different habitat problems.
In some locations, historic clearing, continuing fragmentation, drought, fire and climate change are reducing habitat quality. Victoria’s own koala strategy describes the state as having experienced widespread historical forest clearing, with continuing habitat loss and fragmentation remaining a concern.
In other places, particularly some coastal and island populations, koalas have become too numerous for the limited supply of their favourite trees.
Heavy browsing can strip manna gums and swamp gums of their leaves. In severe cases, trees die and koalas can eventually face starvation.
Commercial blue gum plantations create another problem.
These plantations can provide plentiful food, shade and shelter. However, they are crops grown to be harvested, not permanent native forests.
When large areas are clear-felled, koalas may be injured, killed or displaced into nearby habitat. Victoria’s koala strategy also warns that short-term plantation protection measures do not solve the longer-term problem of displaced koalas trying to find somewhere else to live.
Plantation trees can provide temporary habitat, but they cannot replace protected and permanently connected native woodland.
South Australia
Koalas are not native to every part of South Australia. Many present-day populations were established following earlier introductions.
Suitable habitat is limited mainly to places such as the Mount Lofty Ranges, Adelaide Hills, Kangaroo Island, the Southeast and parts of Eyre Peninsula.
Favoured South Australian food trees include:
- rough-barked manna gum;
- South Australian blue gum;
- river red gum;
- swamp gum;
- messmate stringybark;
- brown stringybark; and
- peppermint box.
South Australia shows that habitat decline is not caused only by bulldozers.
In some areas, koalas are packed into small or isolated habitat patches and cannot spread safely. They may overbrowse manna gums and blue gums until the canopy becomes thin or dies.
Fragmentation can make this worse because roads, farms and suburbs prevent koalas from reaching other food trees. South Australia has only relatively small areas containing the right mixture of suitable trees, placing extra pressure on locations where koalas occur in high numbers.
The answer is not simply to plant thousands of one favourite species.
Healthy landscapes need enough space, connected corridors, several suitable local tree species and careful management of both tree health and koala numbers.
Western Australia, the Northern Territory and Tasmania
Wild koalas do not naturally live in Western Australia, the Northern Territory or Tasmania.
Their modern natural range follows eastern and south-eastern Australia, from Queensland through New South Wales and the ACT to Victoria and South Australia.
These jurisdictions can still contribute through wildlife education, scientific research and support for national conservation.
However, planting eastern-state koala trees outside the koala’s natural range is not a substitute for protecting habitat where wild koalas belong.
Why Koala Habitat Is Under Pressure Across Australia
The National Recovery Plan describes habitat loss, fragmentation and degradation as primary threats to koalas.
It reports that nearly 40% of Australia’s forests had been lost since European settlement. Anecdotal evidence would suggest even more than 40% has been cleared. Much preferred koala habitat overlaps fertile coastal and river soils that people also want for farming, towns, roads and industry.
The greatest dangers are connected.
Clearing removes food and shelter immediately.
Fragmentation leaves small islands of trees separated by roads, fences, farms and open land.
Heatwaves and drought reduce moisture in leaves and make it harder for koalas to stay cool and hydrated.
Bushfires can kill animals and remove entire habitat patches.
Disease can have a greater effect on koalas already weakened by stress and poor nutrition.
Roads and dogs become more dangerous when koalas are forced to travel across the ground.
Koala populations in Queensland, New South Wales and the ACT are nationally listed as endangered. The national assessment was based partly on an estimated population decline of more than 50% over three generations, together with continuing threats including habitat loss, climate change and disease.
Victoria and South Australia have different population patterns. Koala numbers are stable or increasing in some places, while other local populations and habitats face clearing, fragmentation, fire, extreme heat, plantation harvesting or severe overbrowsing.
It is therefore more accurate to say koala habitat is under pressure throughout the species’ range than to claim every local koala population is declining in exactly the same way.
Replacement Trees Must Belong to the Local Area
People often say that replacement trees should be “endemic.”
In restoration work, the more exact terms are locally indigenous and local provenance.
A locally indigenous species is one that naturally belongs in that particular district and ecosystem.
Local-provenance plants are usually grown from seed collected from healthy plants near the planting site or from locations with similar conditions. This gives the seedlings a better chance of surviving.
An Australian native tree is not automatically suitable everywhere in Australia.
A species from tropical Queensland may be completely wrong for a cool Victorian woodland. Even within Queensland or New South Wales, a tree suited to a wet coastal creek may struggle on a dry ridge.
Official restoration guidance warns against introducing a native species simply because it is Australian. If it does not naturally grow in that local ecosystem, it may be the wrong choice.
Plantings should copy the natural vegetation community that belongs on the site.
They should contain local food trees, shelter trees, shrubs, grasses and other native plants—not a plantation-like row of one tree species.
Advice should be obtained from the relevant council, state environment agency, Landcare group, Traditional Custodians, local native nursery or qualified ecologist.
What Australia Must Do Now
Protect mature trees first
The quickest way to create a 50-year-old koala tree is to avoid cutting down the one already standing.
Protect habitat, not only occupied trees
A tree should not become disposable simply because no koala was sitting in it during one inspection.
Koalas move. Seasons change. A tree that appears empty today may provide food or shelter tomorrow.
Reconnect the landscape
Wide, vegetated corridors along creeks, ridgelines, roadsides and property boundaries can reconnect feeding and breeding areas.
Safe road crossings, lower speeds, koala-friendly fencing and responsible dog control can reduce danger along those routes.
Restore damaged land properly
Natural regeneration should be encouraged wherever possible. Planting can then fill gaps and return missing species.
New trees require years of weed control, watering, guards, maintenance and monitoring. Planting a seedling and walking away is not habitat restoration.
Plan development around habitat
Wildlife should not be treated as an obstacle to be moved after development has been approved.
Moving a koala does not replace its food trees, shade, home range or connections with the surrounding landscape.
Measure survival, not planting numbers
A photograph of volunteers standing beside 10,000 seedlings is encouraging, but the real questions must be asked years later:
How many trees survived? Are they the correct species? Are they connected to existing habitat? Were mature trees protected? Are koalas using the restored area safely?
Plant for Tomorrow. Protect Today.
Tree planting gives us hope.
Every properly planned local tree can become part of a future corridor, feeding area or refuge. Communities should keep planting them.
But Australia cannot plant its way out of continuing habitat destruction.
A mature koala tree may have taken decades to build its trunk, branches and canopy. It already provides food, shade, strength and safety.
Removing it and planting a small replacement creates a habitat debt that may last at least 40 to 50 years or longer. Some koalas living today will never receive the benefits of that replacement.
The order matters:
Protect first. Restore second. Plant for the future.
Koalas do not need promises that a forest will exist one day.
They need the trees still standing today.
Frequently Asked Questions
How long before a newly planted tree helps a koala?
Some fast-growing eucalypts may provide leaves and be used within three to five years. However, developing the strong branches, broad canopy and dependable food supply of mature habitat can take at least 40 to 50 years or longer.
Can I plant any eucalyptus tree for koalas?
No. Koala preferences change according to region, soil and climate. Use locally indigenous species, preferably grown from local-provenance seed, and follow planting guidance for your council area or regional ecosystem.
Do koalas use trees only for food?
No. Koalas also need trees for sleeping, shade, protection from weather, movement and social behaviour. Some valuable shelter trees are not major food trees.
Why can’t koalas simply move after their trees are cleared?
Moving between habitat patches uses energy and can force koalas across roads, open ground, fences and backyards containing dogs. Nearby habitat may already be occupied or may not contain the correct trees.
Is tree planting enough to save koalas?
No. Planting is essential for future habitat, but it must be combined with protection of mature trees, connected wildlife corridors, safer roads, responsible pet ownership and long-term care of restored land.
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