This study program is an initiative of The Koala Study Program at the University of Queensland and the Koala Research Centre of Central Queensland (Central Queensland University) & Central Queensland Koala Volunteers.
Project Overview of koala research on St.Bees Island, Queensland
Records of translocations 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 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 neighboring islands this project is at the forefront of both management and scientific investigation of the koala in Australia.
Projected Outcomes
The Koala Study Program at the University of Queensland and The Koala Research Centre at Central Queensland University have combined to undertake The St Bees Koala Study. The St Bees Island Koala Study represents a unique opportunity, both in terms of scientific endeavor and for the affiliated funding partner.
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 programme in the region for the St Bees koalas.
The Koala is perhaps Australia’s most endearing and highest profile native fauna, commanding a prized and responsible position. It is the flagship of many conservation efforts and association with the conservation of the koala reflects favourably on research partners. The unique location at St Bees itself is interesting from a public perception, hence the opportunities to promote this study and the support of the granting body in the print and visual media would complement the scientific publications from this work.
Detailed Project Plan
Preliminary surveys of the area of the research project have been undertaken; the results of these indicate a sizeable group of koalas to inhabit St Bees Island, with several smaller groups inhabiting nearby island. These smaller groups are believed to have been founded by individuals from the St Bees population.
The research team will initiate the proposed study in July 2000, visiting the island for some 28 days during which koala catching, sampling, monitoring and radio-tracking procedures will be undertaken. All procedures will be conducted in accordance with The University of Queensland Animal Ethics Committee approval and Environmental Protection Agency Scientific Purposes Permit held by The Koala Study Program.
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 be 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 tethered the koala, ensures that it is unable to ascend the tree.
Radio relocation
Koalas are fitted with collar-mounted radio transmitters, which enabled their movements to be monitored. Captured adult koalas are fitted with rubber collars with aluminum 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 faecal pellets, according to the method of Tun (1993). This method has been used in Queensland (Tun 1993; Hasegawa 1995) and N.S.W. (Lloyd & Fisher 1997) to determine local diet preferences for koalas and has recently been validated in trials with captive koalas subject to species-controlled feeding procedures (Ellis et al. 1999).
A local reference slide collection is made prior to the commencement of dietary analysis, using the locally occurring Eucalyptus and other species. Leaf segments (1 cm x 1 cm) from these species are fixed (70% ethanol: 5% glacial acetic acid: 5% formalin at 90: 5: 5 v:v) then boiled (hydrogen peroxide: glacial acetic acid at 6: 1 v:v) in a fume hood. After washing with water, the adaxial and abaxial cuticle layers of the specimens are removed with forceps and stored in ethanol (60%). These layers are then stained in aqueous gentian violet for 30 sec, dehydrated, cleared in xylene and mounted under cover slips in xam (Merck, Kilsyth, Victoria) on microscope slides. These slides are examined under a light microscope at x 10 and x 40 magnification using an eye-piece micrometer as reference for each species’ identification.
Tun (1993) provides a complete description of the diagnostic features used to distinguish Eucalyptus and other potential koala fodder species on the basis of microscopic analysis of leaf material. The mean size and density of the stomatal complex is a highly reliable diagnostic character and the number of subsidiary cells is also used to distinguish species.
Fresh faecal pellets are collected, when present, from the base of the tree in which each koala is located during the radio-tracking procedures. Since all known koalas at the study site are radio-collared, fresh pellets found at the base of a tree can be assigned to the koala found in the tree with a degree of confidence. Up to 10 pellets will be collected and stored in small press-seal plastic bags (6 cm x 12 cm) at -4OC until the pellets are processed. A single pellet from each collection (4 -15 collections per koala) is analysed and a composite description of the diet of each koala determined. We have shown that species eaten by koalas can appear in faecal pellets within 11 h post-feeding and could remain present for up to 154 h post-feeding (Ellis et al.1999).
The pellets are washed with tap water and several drops of detergent (Decon) in centrifuge tubes (10 ml), overnight on an orbital shaker (Bio-Line, Edwards Instrument Co. N.S.W.) at 37oC. The pellets are then crushed using forceps prior to the tubes being centrifuged (3000 rpm for 3 min). The supernatants are poured off and the tubes filled with water, shaken and centrifuged again. This washing is repeated three times after which the tubes are filled with 4% sodium hypochlorite and left until any remaining mesophyll had been removed (up to 5 days). The bleached material is then centrifuged and washed as before and alcohol (60 %) added to the tubes prior to staining.
A small amount (0.5 ml) of the bleached material is adhered to a microscope slide using Mayer’s albumen and stained with gentian violet. This preparation is then dehydrated, cleared in xylene and mounted under a coverslip using xam.
These permanent slides are compared with the reference slides at x 40 magnification by systematic traversing to avoid double counting of fragments. In each slide, a sample of 100 fragments are identified and the frequency of occurrence of each species is recorded.
Analysis of leaf moisture
Leaf moisture is determined according to the method of Ellis et al. (1995). Vegetation monitoring plots are established across the study area including all of the tree associations used by the koalas in the study. At each plot, five individual trees of each potential food species are sampled to determine absolute leaf moisture content of these trees during the study period. Six of the newest fully expanded leaves are cut at first light (when leaf moisture is at maximum) from the lower third of the north-east aspect (for consistency) of the canopy of each tree. The leaves are transferred to a previously tared bottle and transported to the laboratory where their fresh weight is determined. The leaves are dried to constant mass after 3 to 5 days in an incubator at less than 60oC. The majority of essential oils in central Queensland eucalypts volatolise at temperatures of 70oC or greater (Melzer and Carrick unpublished data). They are then warm weighed to determine dry weight. Leaf moisture is determined by the difference between wet and dry weights.
Analysis of water turnover and field metabolic rate (FMR)
Koalas will also be captured for analysis of FMR using doubly labeled. Upon capture, each animal is weighed and a 2 ml blood sample collected by cephalic venipuncture. Tritiated water (0.5 ml, 370 MBq/ml (5 mCi/ml)) followed by 1.0 ml O18 (97% atoms excess) is infused through the same needle to the cephalic vein, and the animal placed in a metabolism cage in a shaded place for a period of two hours (Ellis & Carrick 1992). Following this period, a 2 ml blood sample is taken from the cephalic vein of each koala, and the koala released into the tree from which it has been caught.
After 7 to 11 days, the koalas are recaptured, weighed, a 2 ml blood sample is collected from each, and they are released at the recapture site.
The blood samples are collected in 5 ml sterile vials and frozen at -20oC. These samples are analysed as described by Ellis et al. (1995). Water is extracted from blood samples by vacuum distillation to dryness to avoid fractionation. Thereafter 100(l of extracted water with 3 ml PCS (Amersham) is counted in a Beckman LS2800 counter. Oxygen 18:16 ratios are determined after Urey exchange using a VG 903 isotope ratio mass spectrometer. Rates of carbon dioxide production and water flux are determined according to the method of Lifson et al. (1955) and Lifson and McClintock (1966).
Genetic analysis
Tissue samples will be collected from non-anaethsetised koalas by using a sterile leather punch to remove a small (3 mm diameter) section of the outermost portion of one ear. This sample is placed in 20% dimethyl sulphoxide in saturated NaCl solution and kept refrigerated until processed.
DNA is extracted from ear clips that have been ground in liquid nitrogen or from the buffy coat using standard protocols. After digestion with proteinase K, contaminating proteins are removed by a phenol/chloroform extraction procedure and the DNA precipitated in salt and ethanol, washed twice in 70% ethanol, resuspended in buffer containing 1mM EDTA and stored frozen.
Genotypes at six variable dinucleotide microsatellite loci used previously for koala population studies are obtained for koalas using standard procedures. The six pairs of oligonucleotide primers are used to amplify loci by PCR (20 secs denaturing at 94oC, 30 secs annealing at 50oC, and 40 secs extension at 72oC) with one of the primers in the reaction labeled with gamma 33P. PCR products are electrophoresed on 6% acrylamide denaturing gels at 45 volts/cm for 1.5 - 3 hours. Gels are dried under vacuum at 80oC and exposed to x-ray film for 2 - 6 days. Allele sizes are scored with reference to a sequence ladder of known size.
Koala Study Program Project background and relevant issues.
The long-term survival of the koala is dependent on the capacity for isolated groups to negotiate population bottlenecks. This project aims to determine the effect of founders on the physiological responsiveness, disease status, reproduction and spatial arrangement of isolated koala groups by comparing apparently stable island populations with their founders and other non-related groups. The adaptive capacity of koalas to environmental factors will be assessed and an understanding of the viability of isolated groups gained.
Features of the scientific investigation
Physiological ecology of island population of koalas. Water balance and field metabolic rate.
Diet, tree use, home range and social interaction.
Health and reproduction.
Genetic analysis of translocated island population of koalas.
Population dynamics of island population of koalas – breeding strategies, viability analysis.
Team Profile
The Koala Study Program at the University of Queensland, led by Dr. Frank Carrick A.M., is the leader in the research of the biology of the koala. Dr. Carrick’s specific input into the conservation of the koala was recognised in 1995 with the awarding of the A.M. The Koala Research Centre of Central Queensland at Central Queensland University, led by Dr. Alistair Melzer, was formed in 1994 and comprises a multidisciplinary team investigating the biology of koalas in a unique bioregion. Working together, the team has published ground breaking information regarding water balance and energy budgets for koalas in central Queensland, and their complementary approaches provide an effective platform to achieve research goals. Recent achievements of the two programs include:
Pioneering the determination of the diet of koalas
Identification of the disease-causing pathogens of koalas
Development of screening tests for diseases in koalas
Use of DNA analysis to describe the breeding behaviour of free-ranging koalas
Pioneering work in the field of artificial insemination in koalas
Identifying the first ever identical twin koalas born in captivity
Pioneering work evaluating stress in koalas
Being awarded The Australian Minerals and Energy Environment Foundation Environmental Excellence Award in 1999 – Dr. Bill Ellis
Contributions to the Koala Study Program, the Koala Research Centre of Central Queensland and the Central Queensland Koala Volunteers are tax deductable.
Dr. Bill Ellis
Research Officer, Koala Study Program
The University of Queensland.
B.Sc. (Hons) Australian National University.
Ph.D. The University of Queensland.
1999 Australian Minerals and Energy Environment Foundation Environmental Excellence Award.
Bill Ellis has been undertaking koala research since he joined The Koala Study Program at the University of Queensland in 1988. He has worked as a koala keeper in a commercial zoo and completed his Ph.D. in the Department of Zoology at the University of Queensland, investigating disease and physiology of koalas in 1997.
Overseeing much of the program’s research field work in central Queensland, Bill has developed an affinity with the country and the koalas of this region and is recognised as a leading scientist investigating koalas in this region.
Key Publications:
Ellis, W., Carrick, F.N., Lundgren, P., Veary, A. and Cohen, B. (1999). The accurate prediction of the dietary composition of koalas from faecal cuticle examination. Aust. Zool. 31(1) 127- 133
Ellis, W.A.H., Sullivan, B.J., Lisle, A.T. and Carrick, F.N. (1998). The spatial and temporal distribution of koala faecal pellets. Wildl. Res. 25: 663-668
Ellis, W.A.H., Melzer, A., Green, B., Newgrain, K., Hindell M.A. and Carrick, F.N. (1995). Seasonal variation in water flux, field metabolic rate and food consumption of free-ranging koalas (Phascolarctos cinereus). Aust. J. Zool. 43:59-68
Ellis, W.A.H., Girjes, A.A., Carrick, F.N. and Melzer, A. (1993). Chlamydial infection in koalas under relatively little alienation pressure. Aust. Vet. J. 70 (11) 427-428
Ellis, W.A.H. and Carrick, F.N. (1992). Total body water and the estimation of fat in the koala. Aust. Vet. J. 69(9): 229-231
Dr Alistair Melzer
Senior Research Fellow
Central Queensland University
Leader, Industrial Land Management Programme
Principal Research Officer, Koala Research Centre of Central Queensland
BSc(Hons), PhD University of Queensland
Alistair Melzer is an ecologist - studying koalas since 1988. He has been in Central Queensland since 1990 and at Central Queensland University since 1994. Alistair’s work on the ecology of koalas (ranging behavior, habitat selection, morphological variation, effects of climate and conservation) has resulted in his being asked to provide expert advice on koala management (NSW State Forests) and conservation (forum for the conservation of the koala, international conference of the Society for Conservation Biology) as well as working with local community and industry. His work in CQ has been possible through strong community support (volunteer time and money) over the last 10 years.
Publications and Reports:
Ellis, W.A.H., Girjes, A.A., Carrick, F.N. & Melzer, A. (1993) Chlamydial infection in koalas under relatively little alienation pressure. Aust. Vet. J. 70 (11) 427 - 428.
Ellis, W.A.H., Melzer, A., Green, B., Newgrain, K., Hindell, M.A. & Carrick, F.N. (1995) Seasonal variation in water flux, field metabolic rate and food consumption of free-ranging koalas (Phascolarctos cinereus). Aust. J. Zool., 43, 59-68.
Houlden, B.A., Costello, B.H., Sharkey, D., Fowler, E.V., Melzer, A., Ellis, W., Carrick, F. Baverstock P.R. & Elphinstone, M.S. (1999) Phylogeographic differentiation in the mitochondrial control region in the koala, Phascolarctos cinereus (Goldfus 1817) Molecular Ecology 8, 999-1011.
Melzer, A., Carrick, F. Menkhorst, P. Lunney, D. & St John, B. (2000) Koala distribution and abundance: an overview, critical assessment and review of conservation implications. Conservation Biology, in press July edition.
Melzer, A. and Houston, W. (1997) Distribution and ecology of the koala. Koala Research Centre of Central Queensland, Faculty of Applied Science, Central Queensland University, Rockhampton, Qld.
Melzer, A. & Lamb, D. (1994) Low density populations of the koala (Phascolarctos cinereus) in Central Queensland. Proc. R. Soc. Qld, 104, 89-93.
Melzer, A., Schneider, M.A. & Lamb, D, (1994) Insects associated with the faecal pellets of the koala, Phascolarctos cinereus Goldfuss. Australian Entomologist, 21 (3), 69-70.
Penn, A.M., Sherwin, W.B., Gordon, G., Lunney, D. Melzer, A. & lacy, R.C. (2000) Demographic forecasting in Koala Conservation. Conservation Biology. In press July edition.
Worthington Wilmer, J.M., Melzer, A., Carrick, F. & Moritz, C. (1993) Low genetic diversity and inbreeding depression in Queensland koalas: implications for conservation. Wildlife Research, 20, 177-188.