Population Trends and the Koala Conservation Debate

A critical issue affecting the long-term management of koalas is their perceived conservation sta- tus. Koalas still occur in many areas throughout their historical range, but numbers of animals are esti- mated to vary from , 100,000 to at least one order of magnitude higher. Complex factors limit free-ranging koala populations, including food tree preferences, history of disturbance, and Chlamydia infection, all of which make longer-term population trends of many populations difficult to predict. Lack of consensus re- garding the size and viability of remaining populations and regarding the extent of and reasons for decline, or overabundance in some instances, hinders the conservation task. A reappraisal of population trends sug- gests that, notwithstanding localized management issues in Victoria and South Australia, overall the species is "vulnerable" on the basis of current World Conservation Union criteria. Recommendations for more effec- tive conservation of koalas include (1) acknowledging the legitimacy of differing perspectives, (2) recogniz- ing the uncertainty and assumptions inherent in population estimates and trends, (3) applying greater rigor and developing better standards for monitoring population trends, and (4) being cautious in assigning con- servation status to national, state, and regional populations.

[1]  Chris R. Dickman,et al.  An ecological approach to identifying the endangered fauna of New South Wales , 1995 .

[2]  R. W. Martin.  Overbrowsing, and decline of a population of the koala, Phascolarctos cinereus, in Victoria. III. Population dynamics , 1985 .

[3]  P. Timms,et al.  Outer Membrane Protein A Gene Sequencing Demonstrates the Polyphyletic Nature of Koala Chlamydia pecorum Isolates , 1997 .

[4]  Graeme Caughley,et al.  Analysis of vertebrate populations , 1977 .

[5]  P. Timms,et al.  Outer Membrane Protein 2 Gene Sequences Indicate that Chlamydia pecorum and Chlamydia pneumoniae Cause Infections in Koalas , 1996 .

[6]  R. Bilney,et al.  Population structure and reproductive status of Koalas on Raymond Island, Victoria , 1988 .

[7]  Graeme Caughley,et al.  Conservation Biology in Theory and Practice , 1996 .

[8]  M. Elgar,et al.  The Use of Corridors by Mammals in Fragmented Australian Eucalypt Forests , 1997 .

[9]  M. Lavin,et al.  ASPECTS OF THE EPIDEMIOLOGY OF CHLAMYDIA PSITTACI INFECTION IN A POPULATION OF KOALAS (PHASCOLARCTOS CINEREUS) IN SOUTHEASTERN QUEENSLAND, AUSTRALIA , 1988, Journal of wildlife diseases.

[10]  B. Gall.  Aspects of the Ecology of the Koala, Phascolarctos cinereus (Goldfuss), in Tucki Tucki Nature Reserve, New South Wales , 1980 .

[11]  M. Hindell,et al.  Habitat Use and Tree Preferences of Koalas in a Mixed Eucalypt Forest , 1987 .

[12]  Rw Martin.  Age-Specific Fertility in Three Populations of the Koala, Phascolarctos cinereus Goldfuss, in Victoria , 1981 .

[13]  G. Gordon,et al.  A koala (Phascolarctos cinereus Goldfuss) population crash during drought and heatwave conditions in south-western Queensland , 1988 .

[14]  John Callaghan,et al.  Determining the distribution of Koala habitat across a shire as a basis for conservation: a case study from Port Stephens, New South Wales , 1998 .

[15]  Bill Phillips.  Koalas: The Little Australians We'd All Hate to Lose , 1996 .

[16]  Keith R. Every.  Evaluation of a Decline in Population of the Koala, Phascolarctos cinereus (Goldfuss) in Ventnor Reserve, Phillip I., Vic., by means of a Triple-Count Technique , 1986 .

[17]  M. Lavin,et al.  Chlamydial disease in koalas. , 1987, Australian veterinary journal.

[18]  K. Handasyde,et al.  Experimental translocation of koalas to new habitat , 1991 .

[19]  D. Lunney,et al.  A Community-based Survey of the Koala, Phascolarctos cinereus, in the Eden Region of South-eastern New South Wales , 1997 .

[20]  M. Hindell,et al.  Tree Use by Individual Koalas in a Natural Forest , 1988 .

[21]  M. Hindell,et al.  Tree Species Selection by Free-Ranging Koala Populations in Victoria. , 1985 .

[22]  H. Cogger,et al.  The Action Plan For Australian Reptiles , 1993 .

[23]  Judy Smith,et al.  Decline of the urban Koala (Phascolarctos cinereus) population in Warringah Shire, Sydney , 1990 .

[24]  K. Handasyde,et al.  Chlamydia infection and infertility in the female koala (Phascolarctos cinereus) , 1984, Veterinary Record.

[25]  W. Sherwin,et al.  Low genetic variability of the koala Phascolarctos cinereus in south‐eastern Australia following a severe population bottleneck , 1996, Molecular ecology.

[26]  D. Augustine.  Modelling Chlamydia–koala interactions: coexistence, population dynamics and conservation implications , 1998 .

[27]  Neil M. White,et al.  Aspects of the ecology of the koala in southeastern Queensland , 1991 .

[28]  C. Krebs.  Ecology: The Experimental Analysis of Distribution and Abundance , 1973 .