Drought-driven change in wildlife distribution and numbers: a case study of koalas in south west Queensland

Seabrook, Leonie, McAlpine, Clive, Baxter, Greg, Rhodes, Jonathan, Bradley, Adrian and Lunney, Daniel (2011) Drought-driven change in wildlife distribution and numbers: a case study of koalas in south west Queensland. Wildlife Research, 38 6: 509-524. doi:10.1071/WR11064

Author Seabrook, Leonie
McAlpine, Clive
Baxter, Greg
Rhodes, Jonathan
Bradley, Adrian
Lunney, Daniel
Title Drought-driven change in wildlife distribution and numbers: a case study of koalas in south west Queensland
Journal name Wildlife Research   Check publisher's open access policy
ISSN 1035-3712
Publication date 2011
Sub-type Article (original research)
DOI 10.1071/WR11064
Volume 38
Issue 6
Start page 509
End page 524
Total pages 16
Place of publication Collingwood, Vic., Australia
Publisher CSIRO Publishing
Collection year 2012
Language eng
Formatted abstract
Context: Global climate change will lead to increased climate variability, including more frequent drought and heatwaves, in many areas of the world. This will affect the distribution and numbers of wildlife populations. In south-west Queensland, anecdotal reports indicated that a low density but significant koala population had been impacted by drought from 2001–2009, in accord with the predicted effects of climate change.
Aims: The study aimed to compare koala distribution and numbers in south-west Queensland in 2009 with pre-drought estimates from 1995–1997.
Methods: Community surveys and faecal pellet surveys were used to assess koala distribution. Population densities were estimated using the Faecal Standing Crop Method. From these densities, koala abundance in 10 habitat units was interpolated across the study region. Bootstrapping was used to estimate standard error. Climate data and land clearing were examined as possible explanations for changes in koala distribution and numbers between the two time periods.
Key results: Although there was only a minor change in distribution, there was an 80% decline in koala numbers across the study region, from a mean population of 59 000 in 1995 to 11 600 in 2009. Most summers between 2002 and 2007 were hotter and drier than average. Vegetation clearance was greatest in the eastern third of the study region, with the majority of clearing being in mixed eucalypt/acacia ecosystems and vegetation on elevated residuals.
Conclusions: Changes in the area of occupancy and numbers of koalas allowed us to conclude that drought significantly reduced koala populations and that they contracted to critical riparian habitats. Land clearing in the eastern part of the region may reduce the ability of koalas to move between habitats.
Implications: The increase in hotter and drier conditions expected with climate change will adversely affect koala populations in south-west Queensland and may be similar in other wildlife species in arid and semiarid regions. The effect of climate change on trailing edge populations may interact with habitat loss and fragmentation to increase extinction risks. Monitoring wildlife population dynamics at the margins of their geographic ranges will help to manage the impacts of climate change.
Keyword Climate variability
Faecal standing crop method
Habitat loss
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 31 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 34 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Sun, 18 Dec 2011, 16:22:13 EST by System User on behalf of School of Geography, Planning & Env Management