Koalas

An iconic Australian marsupial, Koalas occur from the tip of topical Queensland, down the east coast of Australia to Victoria and South Australia.

Due to hunting, bush fires, drought, and destruction of habitat from agriculture or urbanisation, Koala populations have dropped significantly over the past century leading to them being listed as a Vulnerable Species in the Environmental Protection and Biodiversity Conservation Act 1999 in Queensland and New South Wales in 2012.

The Koala diet consists mainly of the leaves from a small number of Eucalyptus species, providing a high fibre, low-protein food source. Koalas feed often, as they are unable to store excess energy as fat. They rely on a slow metabolism and conservation of energy through sleep and resting. Koalas generally feed for two to four hours every day, usually in the evening, or in drier climates, in the morning to collect moisture from the dew on leaves.

Koalas generally show a preference for younger foliage, as it usually contains more nitrogen, moisture, and sugars than older, mature foliage. The palatability of certain species depends a lot on the available nutrient in the soil, as trees growing in poor nutrient areas tend to produce compounds in their leaves that deter feeding as a protection for their foliage.

Koalas are relatively sedentary and localised in their movement. Females generally require a minimum 1 hectare of good quality habitat in areas of high soil fertility and good rainfall, while males require a minimum of 2 hectares.

Koalas are asocial animals, the only bonding occurring between the mother and offspring (known as joeys) up to the age of 20-36 months when the young disperse to find their own homes. Male Koalas communicate with loud bellows to intimidate rivals and attract females. They also mark their territory with secretions from a scent gland located on their chests.

Koalas usually live up to 10 years for males, and 12 years for females.

Creating a Koala Sanctuary

• Unless they are connected to adjacent areas of habitat, Koala sanctuaries should be a minimum of 50 (ideally 100) hectares in size.
• Connectivity through the use of wildlife corridors is essential, as Koalas generally will not move through more than 200m of open ground. Plantings should be more of a rounded or square shape rather than a long narrow strip, unless they are part of a wildlife corridor or are following a riparian zone along a watercourse.
• Tree density should be 100 trees per hectare, at 10 m spacing.
• Plant a range of different species to ensure there is always a wide assortment of food choices.
• Koalas also use many species of Acacia, Casuarina, and Melaleucas for shelter on hot days.
• Avoid barriers that will impede the movement of Koalas between areas of habitat, such as roads, fences, retaining walls, and buildings.
• Ensure there is no threat from dogs – wild or domestic.

Koala Food Trees

Botanical Name	Common Name
Eucalyptus agglomerata	Blue-Leaved Stringybark
Eucalyptus amplifolia	Cabbage Gum
Eucalyptus blakelyi	Blakely's Red Gum
Eucalyptus bridgesiana	Apple Box
Eucalyptus cinerea	Argyle Apple
Eucalyptus cypellocarpa	Mountain Grey Gum
Eucalyptus dealbata	Hill Redgum
Eucalyptus dives	Broad Leaf Peppermint
Eucalyptus eugenoides	Thin-leaved Stringybark
Eucalyptus globulus spp maidenii	Maiden's Gum
Eucalyptus mannifera ssp mannifera	Red Spotted Gum
Eucalyptus melliodora	Yellow Box
Eucalyptus nicholii	Willow Peppermint
Eucalyptus obliqua	Messmate
Eucalyptus ovata	Swamp Gum
Eucalyptus parramattensis	Parramatta Red Gum
Eucalyptus pauciflora	Snow Gum
Eucalyptus piperita	Sydney Peppermint
Eucalyptus polyanthemos	Red Box
Eucalyptus punctata	Grey Gum
Eucalyptus quadrangulata	White Topped Box
Eucalyptus radiata	Narrow-leaved Peppermint
Eucalyptus rubida	Candlebark
Eucalyptus tereticornis	Forest Red Gum
Eucalyptus viminalis	Ribbon Gum

If you would like further advice on designing your Koala sanctuary, we offer a consultation service.