Background

 Records of translocation of koalas include small numbers moved from mainland Australia as far back as the late 19th century, when several formed the founding populations on Islands off the Victorian coastline. The subsequent management problems and further translocations of these koalas have been well documented, representing one of the most contentious and disconcerting issues in native animal management in Australia’s history.
 There is no doubt that serious issues remain for the management of koalas in south-east Australia, and that many of these issues relate directly to the problems which have resulted from apparent overpopulation, population crashes and repeated translocations of these animals in that region. Some researchers contend that koalas are unable to survive in such island populations, that the effects of in-breeding and overpopulation inevitably destroy both the koalas and their environment.
 Koalas occur on several islands off the coast of Queensland. In some cases, such as St Bees, there are records of the translocation of these koalas from the mainland. In the case of the St Bees population, the founding population on the mainland has suffered considerable habitat alienation, and the future of that population is in doubt as a result.
 The koalas at St Bees inhabit a tropical continental island some 30km from the coast at Mackay. A recent survey by the study team revealed a relatively dense (by Central Queensland standards) and healthy group of koalas living across several areas on the island. There exists a unique opportunity to examine the population dynamics, eco-physiology and genetics of this population, which may hold the key to the recolonisation by koalas of revegetated areas of the mainland in the future. In the face of considerable land clearing and development both on the mainland and on neighbouring islands this project is at the forefront of both management and scientific investigation of the koala in Australia.
This research project is designed to provide answers to fundamental questions about the biology of the koala which underpin the long term conservation of the koala in Australia. The unique environment, healthy population of koalas and absence of external impacts at the site chosen for this project provide the base for the next step in understanding how this animal’s future is to be secured, through the development of a regional koala strategy in Queensland.
 The project involves investigating the physiology, ecology and social and genetic dynamics of and isolated group of koalas living in an island ecosystem off the coast of central Queensland.
 
 

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Projected Outcomes

The St Bees Island Koala Study is now funded by The Earthwatch Institute, with four or five expeditions per year led by Principal Investigators Dr. Alistair Melzer and Dr. Bill Ellis. The St Bees Island Koala Study represents a unique opportunity, both in terms of scientific endeavour and opportunities for interested funding partners.
Outcomes from this project will include:
* Survey of Island population of koalas to investigate population densities, home range sizes and population structure.
* Data describing the eco-physiology of a free-ranging population of koalas living in an island environment. This will include water balance and investigation of field metabolic rate.
* Detailed information describing the genetics and population dynamics of a translocated, island group of koalas, including the examination of founder effects on this and other groups. This has relevance to the viability of this and the groups of koalas founded from the St Bees group.
* Management recommendations for island and mainland populations of koalas, and development of a regional koala recovery strategy.
* Development of community based koala restoration program in the region for the St Bees koalas.

Surveys

Surveys consist of systematic searches of the study site by experienced researchers walking in a set formation using compass and GPS information, searching for scratch marks, koala faecal pellets and koalas in trees. By this means the presence or absence of koalas can be determined and koalas located for capture when required.

Capture of koalas

The terrain at St Bees is too rough for wheeled vehicles such as bucket trucks, which can assist in the capture of koalas. Koalas are therefore captured by scaling the tree in which the koala is sitting, securing a tether to the koala and encouraging the koala to descend by waving a rag tied to a pole above its head. Constant tension placed on the koala by a person on the ground holding the rope, which tethers the koala, ensures that it is unable to ascend the tree.

Radio relocation

Koalas are fitted with collar-mounted radio transmitters, which enable their movements to be monitored.  Captured adult koalas are fitted with rubber collars with an aluminium housing containing a 3.5 volt lithium battery and transmitter (Titley Electronics, Australia).  An antenna extending from the transmitter housing is strapped with insulation tape against the collar.
A Regal 2000 receiver and 3 element Yagi antenna (Titley Electronics, Australia) are used to radio-track koalas. Each transmitter emits an individual frequency between 150 and 152 MHz.
Dependant young (aged less than one year) are not collared since they generally occupy the same tree as their mother and are observed when their mother is located. Sub-adult koalas (aged between one and two years) may be fitted with modified collars containing an elastic section to prevent discomfort during growth.
Radio-collared koalas are observed daily.  The type of tree used by the koala and plant community it is in is recorded to allow an understanding of habitat use.  The location of each tree is determined using a GPS and mapped in a GIS providing data on how far the koalas move, and what area they use and how they interact.

Diet analysis

Diet analysis is carried out using the unique method developed by the Koala Study Program.

Funding

The support of The Earthwatch Institute has made this project a successful and productive research initiative, however, we seek partners in this research to support our teams and students complete the work.