Koalas in Victoria

Introduction

Compared to other Australian states, Victoria has a large and thriving Koala population.

That means Victoria has a responsibility to manage its Koala populations to ensure that the species continues to flourish in the wild without damaging other natural values. This responsibility is led by the Department of Environment and Primary Industries along with Parks Victoria.

Management of Koalas in Victoria has been an active and evolving process for over 75 years. Now, with Victoria's Koala Management Strategy, we have a formally adopted plan to guide management actions and policy decisions.

This strategy has been prepared after consultation with community groups and relevant Government agencies.

The aim of the Victorian Koala Management Strategy is to ensure that viable wild populations of the Koala persist wherever suitable habitat occurs throughout their natural range in Victoria.

The Victorian Koala Management Strategy

A copy of the Victorian Koala Management Strategy can be downloaded here:

Victorian Koala Management Strategy [PDF File - 1.7 MB]

Victoria has the largest number of wild Koalas in Australia. In some areas, population densities are so high that they put unsustainable pressure on tree species: this can become a direct threat to forest patches. In other areas, management support is needed to help reverse the declining numbers.

The strategy addresses 11 key issues affecting Koala populations in Victoria:

  • Defining, ranking and conserving habitat
  • Monitoring populations
  • Managing over-browsing
  • Managing genetic structure
  • Investigating the role of chalmydophila in population processes
  • Understanding population demographics
  • Managing interactions with people
  • Managing captive Koalas
  • Managing sick and injured Koalas
  • Involving the community
  • Implementing the strategy

How you can help

Please report sick or injured Koalas to the Department of Environment and Primary Industries on 136 186 or phone RACV Wildlife Connect on 13 11 11 to be connected to the nearest wildlife shelter operator.

Please report signs of over-browsing to local DEPI or Parks Victoria staff, or contact the Department of Environment and Primary Industries on 136 186.

Questions & Answers – Developing a Victorian Koala Management Strategy

Why is there a need for Koala management?
Victoria has the largest number of wild Koalas in Australia. In some areas, Koalas are overpopulated; this can cause a decline in available food supplies and lead to mass starvation. In some other areas Koala numbers are in decline, so it is equally important that we can provide management support.

Where are the Koala over-populated areas?
The areas where Koala numbers are too high are Mt Eccles National Park, Snake Island, French Island, Raymond Island and parts of the Otway forests.

Has there been Koala Management before now?
In Victoria, Koalas were almost wiped out by the 1920s. A sustained re-introduction program over 75 years has resulted in Koalas now occupying most of the available habitat in this State.

What are the key issues that influence Koala population trends?
Key issues that influence Koala population trends are the extent and quality of available habitat, the presence or absence of the disease Chlamydia in a population, and the nutritional quality of the eucalypt leaves available at a given site.

What is the aim of the management strategy?
The strategy aims to ensure that viable wild Koala populations persist wherever suitable habitat occurs throughout the species' natural range in Victoria.

What organisations are involved in the Koala management?
The Department of Environment and Primary Industries (Biodiversity and Natural Resources Division, Parks and Forests Division), Parks Victoria, Catchment Management Authorities and Local Government.

How will Koala populations be managed where over-browsing is a problem?
A major development has been the successful trialling of a contraceptive to limit population growth at sites where over-browsing threatens ecological values. The contraceptive is a progestin hormone, implanted beneath the skin in a slow-release tube. This method has proven highly effective during a six-year trial at Tower Hill State Game Reserve, and a large-scale trial run by Parks Victoria is scheduled to begin in the Spring of 2004 at Mt Eccles National Park.

How much will this strategy cost to implement?
Compared to previous management strategies (catching the Koalas and relocating them), the implementation of the Victorian Koala Management Strategy will be cost-effective.

Have there been tests on the Koalas to prove success of the use of contraceptives in Koalas?
Slow-release hormone implants have successfully prevented conception for more than six years in a DEPI trial undertaken on wild Koalas at Tower Hill State Game Reserve.

What other strategies have been tried?
Since 1923 Koala over-browsing has been managed by relocating surplus animals to habitat left vacant by the population crash in the first decades of the twentieth century.

Over recent years, surgical sterilisation has been used, which has been shown to result in unacceptable levels of mortality in some circumstances. Management of Koalas in Victoria has been an active and evolving process for over 75 years.

What is involved in implanting the slow-release hormone?
The implant is a narrow tube about 3 mm in diameter and 40 mm long. It is inserted beneath the skin between the shoulder blades using a special applicator.

Will this contraception procedure be implemented in Koalas state-wide, or just in the problem areas?
Contraception is an expensive and intrusive management option. It will be used only where over-browsing of food trees is a serious problem and where there is no alternative means of population control.

Do the contraceptives have any side effects that will harm the Koalas?
No harmful side effects have become apparent in the trials or in other mammals to which they have been applied. Koalas which have been implanted as part of the Mount Eccles trial will be monitored throughout.

How will they keep record of the Koalas with contraception?
All Koalas implanted with contraceptive devices will be ear-tagged with numbered plastic swivel sheep tags and will also be tagged with a sub-dermal PIT tag (Passive Integrated Transponder).

How will the Koalas be captured?
Safe handling of Koalas is imperative. Trained Koala catchers, mostly staff of Parks Victoria or DEPI, use the noose and flag technique to guide a Koala down the tree to where it can be safely grasped and placed in a hessian sack.

Did you know?

  • Fragmentation of habitat is a serious issue for Koala conservation because Koalas have a specialised low-energy, low-nutrient diet. This means that Koalas have a limited amount of energy available to use travelling between patches of food trees.
  • Koalas live for up to 20 years in the wild.
  • Koalas only have one offspring in a year, usually in summer.
  • Koalas breed from September to March with a single young being born after a 33 to 35 day pregnancy. The baby Koala, called a "joey", remains in the mother's pouch for approximately six months. Weaning occurs at one year of age.
  • Male Koalas can weigh up to 14kg and females up to 10 kg.
  • Koalas are nocturnal animals, and are most active just after sunset.
  • Koalas are not bears. They are marsupials – mammals whose young are born at a very early stage of development and are then nourished in a pouch.
  • In the past, Koalas were killed for their fur. From 1919 to 1924, eight million Koalas were killed. Today, the Koala is threatened by domestic dogs and by vehicle traffic. But by far the biggest threat to Koalas is habitat loss.
  • Because of their low energy diet of eucalypt leaves, Koalas must rest for much of the day – they are often active for only about four hours out of the 24 hour day, usually after dark.
  • Victoria’s Koala population is thriving and does not meet the criteria for listing as a threatened species.
  • Koalas' fur is different in different parts of Australia. In the southern parts of Australia, it is longer and shaggier than in the north in order to keep them warm in the cold southern winters.
  • According to settlers, Koalas were rarely encountered in Victoria in the 1830s. By the 1860s, Koala populations were increasing in size, possibly due to a decline in hunting pressure from Indigenous Australians. By the early 1900s, Koalas were heavily hunted by European settlers for their fur, which was exported to Europe. Consequently, Koala numbers crashed to very low levels.
  • Koalas have been translocated from heavily-populated areas like Phillip, French and Quail Islands to unoccupied habitat throughout their former Victorian range. About 23,000 Koalas have been translocated to more than 200 release sites across Victoria, initially as a re-introduction program, more recently purely to manage over-population issues. This represents the largest and most sustained wildlife re-introduction program ever undertaken.
  • Koalas do not normally share trees and, in prime quality habitat, have territories ranging from 1.2 to 1.7 hectares.

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