Koalas face many threats in an increasingly cleared, developed and fragmented landscape.
The biggest threat to koalas is habitat loss. Much of the koala's habitat in Queensland overlaps with areas where significant clearing has occurred, and continues to occur, for urban, industrial and rural development.
In South East Queensland, the human population is increasing by more than 1000 people a week. This rapid population growth and increased need for houses is placing considerable pressure on the limited remaining koala habitat.
As habitat patches become smaller and more fragmented, koalas are more likely to move through developed areas. In developed areas, koalas have to cross roads and move through properties where they may be attacked by dogs or drown in backyard swimming pools.
After habitat clearing, the most serious threat to koalas is death from car hits. In South East Queensland, an average of almost 300 koalas are killed each year by motor vehicles, based on wildlife hospital records in the period 1997 to early 2011.
Disease also threatens koalas. Loss of habitat, including loss of food and shelter, is a major stress for koalas. During times of stress, koalas are prone to outbreaks of the disease Chlamydia. Chlamydia is a bacterial infection which affects almost all koalas in South East Queensland. The disease weakens the immune system and causes various problems, including blindness and female infertility. In severe cases, it can cause death. Infertility from Chlamydia is a contributing factor to the current decline in koala numbers.
Another major threat to koalas is dogs. More than 100 koalas are hospitalised each year in South East Queensland after being attacked by dogs. Around 75 per cent of these koalas will die from their injuries. On average that's 75 koalas killed each year from dog attacks. Many dog attacks go unreported so the number of dog attacks is likely to be even higher.
South East Queensland was once home to one of Australia's largest population of koalas. Today, they are under serious threat from development, cars, dogs and stress-related diseases.
Everyone has a role to play in protecting South East Queensland's koalas.
Below are some ways to help ensure koalas are here for keeps.
A drive carefully road sign
Koala crossing a road in the daytime
- Cars kill koalas.
- Around 340 koalas are taken to Moggill Koala Hospital, Currumbin Wildlife Hospital and Australian Wildlife Hospital every year due to car hits.
- Around 80 per cent of car hits are fatal.
How to help
- Remember: koalas need to cross roads too!
- Obey speed limits.
- Look for koala crossing signs.
- Slow down and watch for koalas crossing roads, particularly at night.
- Report injured or dead koalas on the roadside via the EHP wildlife hotline on 1300 130 372 (press 1, then 2), the RSPCA on 1300 ANIMAL (1300 264 625) or contact your local wildlife rescue service.
- Read more about koalas and cars.
A restrained dog will help protect koalas
- Dogs can kill koalas.
- Around 100 koalas are taken to Moggill Koala Hospital, Currumbin Wildlife Hospital and Australian Wildlife Hospital every year because of dog attacks.
- Around 75 per cent of dog attacks on koalas are fatal.
- Many dog attacks aren’t reported so the actual figures may be higher.
How to help
- Keep dogs confined or restrained at night.
- Remember: a dog doesn't need to bite a koala to seriously cause harm—a barking dog can severely stress a koala which can cause the stress-related disease Chlamydia.
- Contact local council to check compliance with dog laws that protect koalas in the area.
- Fence off a dog play area with koala exclusion fencing. This will separate the dog from the rest of the yard so koalas can cross without being harassed.
- Koala exclusion fencing must:
- be at least 1.5 m high
- be made of solid material (e.g. tin, steel or chainwire with sheet metal attached to the top)
- have no gaps in the fence
- have no trees or shrubs growing or overhanging within 3 m of the fence
- Koala exclusion fencing must:
- Read more about koalas and dogs.
Koala in search for a tree
Example of a koala-friendly fence.
Placing a timber pole on the side of fencing can help koalas leave a property
- Koalas cross backyards, lawns, bushland, sporting fields, golf courses, roads, footpaths and open areas to find food trees and mates.
- Koalas walk along the ground and can travel long distances to get to a tree.
- Koalas on the ground are particularly vulnerable.
How to help
- If a koala is seen climbing down a tree, stand still and let it move freely.
- Plant koala food trees. (see availability)
- Make fences koala-friendly so koalas can safely move in and out of each property.
- To create koala-friendly fencing:
- Make it climbable—use timber posts and rail, chain wire or slats with at least 1 cm gap between each slat.
- Ensure it can be passed through or over by a koala. Include a 30 cm gap from the ground to the first rail or strand.
- Put a plank along the top of the fence to provide a koala walkway.
- Plant trees close to both sides of the fence so koalas can cross over.
- For steel fencing (such as Colorbond), place wooden poles (at least 10 cm wide) at a 45° angle to the base of the fence so koalas can climb up, as pictured. It is a good idea to also speak to neighbours to see if they can put a pole on their side so a koala can climb safely to and from the ground.
An example of rope and float in a pool. Tie one end to a tree or stake. This provides the koala a way to climb out if they fall in.
- Use a pool cover that is tight, secure and will not sink if a koala walks on it.
- Install a fence to keep koalas out of the pool area (e.g. transparent glass, perspex or steel).
- Install a rope. Attach one end of a thick rope (5 cm in diameter and 2 m long—marine rope is ideal) to a float (like an empty milk bottle) in the pool and tie the other end securely to a tree, post or fence. This can save a koala from drowning by giving it something to help it climb out of the pool.
- All new pools built in 'Koala Habitat Areas' (see availability) must incorporate one or more of these:
- beach-type access where the water is level with part of the pavement so koalas can get out easily
- steps that are big enough to allow koalas to climb out
- koala exclusion fence (e.g. transparent glass or perspex with no gaps).
Search 'koala' on the following websites:
- Redland City Council
- Moreton Bay Regional Council
- Brisbane City Council
- Logan City Council
- Gold Coast City Council
- Martin, R.W. and Handasyde, K.A. (1995) Koala Phascolarctos cinereus, in Strahan, R. (ed.), The Mammals of Australia, Reed Books, Sydney.
- Martin, R. and Handasyde, K. (1999) The Koala: Natural History, Conservation and Management, New South Wales University Press, Kensington.
- Koalas in Pine Rivers Shire: distribution, abundance and management (see availability)
- Trees for koalas: coastal South East Queensland (see availability)
- Report on Koala Coast koala surveys (see availability)
The documents referred to on this page are available from the department’s online library catalogue.