Pacific Conservation Biology Pacific Conservation Biology Society
A journal dedicated to conservation and wildlife management in the Pacific region.
RESEARCH ARTICLE

The remaining koalas (Phascolarctos cinereus) of the Pilliga forests, north-west New South Wales: refugial persistence or a population on the road to extinction?

Daniel Lunney A B K , Martin Predavec A , Indrie Sonawane A , Rodney Kavanagh C D , George Barrott-Brown E , Stephen Phillips F , John Callaghan F , Dave Mitchell G , Harry Parnaby A , David C. Paull H , Ian Shannon A , Murray Ellis A , Owen Price I and David Milledge J
+ Author Affiliations
- Author Affiliations

A Office of Environment and Heritage NSW, PO Box 1967, Hurstville, NSW 2220, Australia.

B School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia and School of Veterinary and Life Science, Murdoch University, Perth 6150, Australia.

C Niche Environment and Heritage, PO Box 2443, North Parramatta, NSW 1750, Australia.

D Present address: Australian Wildlife Conservancy, GPO Box 4301, Sydney, NSW 2001, Australia.

E Office of Environment and Heritage, PO Box 2111, Dubbo, NSW 2830, Australia.

F Biolink Ecological Consultants, PO Box 3196, Uki, NSW 2484, Australia.

G Australian Koala Foundation, GPO Box 265, Brisbane, Qld 4001, Australia.

H Ethical Ecology, PO Box 67, Coonabarabran, NSW 2357, Australia.

I School of Biological Sciences, University of Wollongong, Wollongong, NSW 2522, Australia.

J Landmark Ecological Services, PO Box 100, Suffolk Park, NSW 2481, Australia.

K Corresponding author. Email: dan.lunney@environment.nsw.gov.au

Pacific Conservation Biology 23(3) 277-294 https://doi.org/10.1071/PC17008
Submitted: 15 March 2017  Accepted: 11 June 2017   Published: 18 July 2017

Abstract

In the 1990s, the Pilliga forests were carrying the largest population of koalas west of the Great Dividing Range in New South Wales (NSW). Whereas the NSW koala population in its entirety was thought to be in decline, the Pilliga population stood out as potentially increasing. By 2007, anecdotal evidence suggested that the population was in decline. We undertook surveys of koalas in the Pilliga forests that repeated surveys undertaken between 1991 and 2011. We found that koalas had declined and were found in only 21% of sites in which they were observed in the initial surveys – by any measure, a 5-fold drop in occupancy in less than two decades is severe. Declines occurred evenly across the Pilliga, with persistence at a site seemingly related to a high initial density of koalas rather than to a slower rate of decline. Sites where koalas persisted were characterised as having higher temperatures and lower rainfall relative to other sites, being close to drainage lines with deeper soils and having a lower occurrence of fire. This pattern fits with the observation in the recent surveys that koalas were next to drainage lines in the western half of the Pilliga and fits with the suggestion that koalas show refugial persistence. Recovery from this point is not assured and will depend on how we manage the landscape, particularly with the threat of climate change. This will likely require active management within an adaptive management framework, such as restoration of refuges, and not simply habitat reservation.

Additional keywords: climate change, extreme weather events, population decline, refuge, refugia


References

Adams-Hosking, C., Grantham, H. S., Rhodes, J. R., McAlpine, C., and Moss, P. T. (2011a). Modelling climate-change-induced shifts in the distribution of the koala. Wildlife Research 38, 122–130.
Modelling climate-change-induced shifts in the distribution of the koala.CrossRef |

Adams-Hosking, C., Moss, P., Rhodes, J., Grantham, H., and McAlpine, C. (2011b). Modelling the potential range of the koala at the Last Glacial Maximum: future conservation implications. Australian Zoologist 35, 983–990.
Modelling the potential range of the koala at the Last Glacial Maximum: future conservation implications.CrossRef |

Adams-Hosking, C., McBride, M. F., Baxter, G., Burgman, M., de Villiers, D., Kavanagh, R., Lawler, I., Lunney, D., Melzer, A., Menkhorst, P., Molsher, R., Moore, B. D., Phalen, D., Rhodes, J. R., Todd, C., Whisson, D., and McAlpine, C. A. (2016). Use of expert knowledge to elicit population trends for the koala (Phascolarctos cinereus). Diversity & Distributions 22, 249–262.
Use of expert knowledge to elicit population trends for the koala (Phascolarctos cinereus).CrossRef |

Aguilera, A. M., Escabias, M., and Valderrama, M. J. (2006). Using principal components for estimating logistic regression with high-dimensional multicollinear data. Computational Statistics & Data Analysis 50, 1905–1924.
Using principal components for estimating logistic regression with high-dimensional multicollinear data.CrossRef |

Anon. (1919). Conditions at Pilliga. The Sydney Morning Herald (NSW: 1842–1954) 2 December 1919. Available at: http://nla.gov.au/nla.news-article15871531 [accessed 8 March 2017].

ASRIS (2011). Australian soil resource information system. Available at: http://www.asris.csiro.au.

Beckers, D., and Binns, D. (2000). NSW Western Regional Assessment Vegetation Survey and Mapping Report (Stage 1). Report prepared for the Resource and Conservation Division, Sydney.

Briscoe, N. J., Handasyde, K. A., Griffiths, S. R., Porter, W. P., Krockenberger, A., and Kearney, M. R. (2014). Tree-hugging koalas demonstrate a novel thermoregulatory mechanism for arboreal mammals. Biology Letters 10, 20140235.
Tree-hugging koalas demonstrate a novel thermoregulatory mechanism for arboreal mammals.CrossRef |

Briscoe, N. J., Kearney, M. R., Taylor, C. A., and Wintle, B. A. (2016). Unpacking the mechanisms captured by a correlative species distribution model to improve predictions of climate refugia. Global Change Biology 22, 2425–2439.
Unpacking the mechanisms captured by a correlative species distribution model to improve predictions of climate refugia.CrossRef |

Channell, R., and Lomolino, M. V. (2000). Trajectories to extinction: spatial dynamics of the contraction of geographical ranges. Journal of Biogeography 27, 169–179.
Trajectories to extinction: spatial dynamics of the contraction of geographical ranges.CrossRef |

Crapper, P. F., Fleming, P. M., and Kalma, J. D. (1996). Prediction of lake levels using water balance models. Environmental Software 11, 251–258.
Prediction of lake levels using water balance models.CrossRef |

Crowther, M. S., Lunney, D., Lemon, J., Stalenberg, E., Wheeler, R., Madani, G., Ross, K. A., and Ellis, M. (2014). Climate-mediated habitat selection in an arboreal folivore. Ecography 37, 336–343.
Climate-mediated habitat selection in an arboreal folivore.CrossRef |

Date, E. M., and Paull, D. C. (2000). Fauna survey of the north-west cypress/ironbark forests. State Forests of New South Wales, Dubbo.

Davies, N., Gramotnev, G., Seabrook, L., Bradley, A., Baxter, G., Rhodes, J., Lunney, D., and McAlpine, C. (2013). Movement patterns of an arboreal marsupial at the edge of its range: a case study of the koala. Movement Ecology 1, 8.
Movement patterns of an arboreal marsupial at the edge of its range: a case study of the koala.CrossRef |

DEC (2006). ‘Atlas of NSW Landscapes: The Mitchell Landscapes.’ (Department of Environment and Conservation: Sydney.)

DECC (2008). Recovery plan for the koala (Phascolarctos cinereus) (Approved). Approved recovery plan for the koala. Department of Environment and Climate Change, Sydney.

Ellis, W., Melzer, A., Clifton, I., and Carrick, F. (2010). Climate change and the koala Phascolarctos cinereus: water and energy. Australian Zoologist 35, 369–377.
Climate change and the koala Phascolarctos cinereus: water and energy.CrossRef |

Fisher, D. O. (2011). Trajectories from extinction: where are missing mammals rediscovered? Global Ecology and Biogeography 20, 415–425.
Trajectories from extinction: where are missing mammals rediscovered?CrossRef |

Gordon, G., Brown, A. S., and Pulsford, T. (1988). A koala (Phascolarctos cinereus Goldfuss) population crash during drought and heatwave conditions in south-western Queensland. Australian Journal of Ecology 13, 451–461.
A koala (Phascolarctos cinereus Goldfuss) population crash during drought and heatwave conditions in south-western Queensland.CrossRef |

Grumley, S. (2015). Still a million wild acres: unlocking environmental archives in the Pilliga Forest. MSc Thesis, Department of Environmental Sciences, Macquarie University, Sydney.

Hesse, P., and Humphreys, G. (2001). Pilliga landscapes, quaternary environment and geomorphology. In ‘Perfumed Pineries: Environmental History of Australia’s Callitris Forests’. (Eds J. Dargavel, D. Hart, and B. Libbis.) pp. 79–87. (Centre for Resource and Environmental Studies, Australian National University: Canberra.)

Hindell, M. A. (1984). The feeding ecology of the koala, Phascolarctos cinereus, in a mixed Eucalyptus forest. M.Sc. Thesis, Monash University, Melbourne.

Kavanagh, R. P., and Barrott, E. (2001). Koala populations in the Pilliga Forests. In ‘Perfumed Pineries: Environmental History of Australia’s Callitris Forests’. (Eds J. Dargavel, D. Hart, and B. Libbis.) pp. 93–103. (Centre for Resource and Environmental Studies, Australian National University: Canberra.)

Kavanagh, R. P., Stanton, M. A., and Brassil, T. E. (2007). Koalas continue to occupy their previous home-ranges after selective logging in CallitrisEucalyptus forest. Wildlife Research 34, 94–107.
Koalas continue to occupy their previous home-ranges after selective logging in CallitrisEucalyptus forest.CrossRef |

Kerle, J. A., Fleming, M. R., and Foulkes, J. N. (2007). Managing biodiversity in arid Australia: a landscape view. In ‘Animals of Arid Australia. Forum of the Royal Zoological Society of New South Wales’. pp. 42–64. (Royal Zoological Society of New South Wales: Sydney.)

Lunney, D. (2001). Causes of the extinction of native mammals of the Western Division of New South Wales: an ecological interpretation of the nineteenth century historical record. The Rangeland Journal 23, 44–70.
Causes of the extinction of native mammals of the Western Division of New South Wales: an ecological interpretation of the nineteenth century historical record.CrossRef |

Lunney, D., Urquhart, C. A., and Reed, P. (1990). Koala Summit: Managing Koalas in New South Wales: Proceedings of the Koala Summit Held at the University of Sydney, 7–8 November 1988. NSW National Parks and Wildlife Service, Sydney.

Lunney, D., Crowther, M. S., Shannon, I., and Bryant, J. V. (2009). Combining a map-based public survey with an estimation of site occupancy to determine the recent and changing distribution of the koala in New South Wales. Wildlife Research 36, 262–273.
Combining a map-based public survey with an estimation of site occupancy to determine the recent and changing distribution of the koala in New South Wales.CrossRef |

Lunney, D., Crowther, M. S., Wallis, I., Foley, W. J., Lemon, J., Wheeler, R., Madani, G., Orscheg, C., Griffith, J. E., Krockenberger, M., Retamales, M., and Stalenberg, E. (2012). Koalas and climate change: a case study on the Liverpool Plains, north-west New South Wales. In ‘Wildlife and Climate Change: Towards Robust Conservation Strategies for Australian Fauna’. (Eds D. Lunney and P. Hutchings.) pp. 150–168. (Sydney.)

Lunney, D., Stalenberg, E., Santika, T., and Rhodes, J. R. (2014). Extinction in Eden: identifying the role of climate change in the decline of the koala in south-eastern NSW. Wildlife Research 41, 22–34.
Extinction in Eden: identifying the role of climate change in the decline of the koala in south-eastern NSW.CrossRef |

Lunney, D., Predavec, M., Miller, I., Shannon, I., Fisher, M., Moon, C., Matthews, A., Turbill, J., and Rhodes, J. R. (2016). Interpreting patterns of population change in koalas from long-term datasets in Coffs Harbour on the north coast of New South Wales. Australian Mammalogy 38, 29–43.
Interpreting patterns of population change in koalas from long-term datasets in Coffs Harbour on the north coast of New South Wales.CrossRef |

McAlpine, C., Lunney, D., Melzer, A., Menkhorst, P., Phillips, S., Phalen, D., Ellis, W., Foley, W., Baxter, G., de Villiers, D., Kavanagh, R., Adams-Hosking, C., Todd, C., Whisson, D., Molsher, R., Walter, M., Lawler, I., and Close, R. (2015). Conserving koalas: a review of the contrasting regional trends, outlooks and policy challenges. Biological Conservation 192, 226–236.
Conserving koalas: a review of the contrasting regional trends, outlooks and policy challenges.CrossRef |

Milledge, D. (2004). Large owl territories as a planning tool for vertebrate fauna conservation in the forests and woodlands of eastern Australia. In ‘Conservation of Australia’s Forest Fauna. Forum of the Royal Zoological Society of New South Wales’. pp. 493–507. (Royal Zoological Society of New South Wales: Sydney.)

Morton, S. R. (1990). The impact of European settlement on the vertebrate animals of arid Australia: a conceptual model. Proceedings of the Ecological Society of Australia 16, 201–213.

NICE and CUCCLG (2012). National significance: the ecological values of Pilliga East Forest and the threats posed by coal seam gas mining 2011–2012. Report prepared by David Milledge, Landmark Ecological Services. Northern Inland Council for the Environment and the Coonabarabran and Upper Castlereagh Catchment and Landcare Group.

NSW NPWS (2002). NSW Western Regional Assessment. Vertebrate fauna survey, analysis and reporting. NSW Resource and Conservation Assessment Council, NSW National Parks and Wildlife Service, Sydney.

Olson, R., Evans, J. P., Argüeso, D., and Di Luca, A. (2014). NARCliM Climatological Atlas. NARCliM Technical Note 4. NARCliM Consortium, Sydney.

Paget, M. (2016). Green Accumulation Index – Landsat, JRSRP algorithm, NSW coverage. NSW Office of Environment and Heritage: Sydney.

Paull, D. C. (2012). Climate change and the Pilliga koalas, preliminary evidence for long-term decline? Paper presented to the 58th Annual Meeting of the Australian Mammal Society, Port Augusta.

Paull, D., and Date, E. (1999). Patterns of decline in the native mammal fauna of the north-west slopes of New South Wales. Australian Zoologist 31, 210–224.
Patterns of decline in the native mammal fauna of the north-west slopes of New South Wales.CrossRef |

Phillips, S., and Callaghan, J. (2011). The Spot Assessment Technique: a tool for determining localised levels of habitat use by koalas Phascolarctos cinereus. Australian Zoologist 35, 774–780.
The Spot Assessment Technique: a tool for determining localised levels of habitat use by koalas Phascolarctos cinereus.CrossRef |

Predavec, M. (2002). Response to disturbance and land management practices: NSW Western Regional Assessments. No. WRA31. Resource and Conservation Assessment Council of NSW: Sydney.

Predavec, M., Lunney, D., Shannon, I., Lemon, J., Sonawane, I., and Crowther, M. (2017). Using repeat citizen science surveys of koalas to assess their population trend in the north-west of New South Wales: scale matters. Australian Mammalogy , .
Using repeat citizen science surveys of koalas to assess their population trend in the north-west of New South Wales: scale matters.CrossRef |

Reed, P., and Lunney, D. (1990). Habitat loss: the key problem for the long-term survival of koalas in New South Wales. In ‘Koala Summit: Managing Koalas in New South Wales’. (Eds D. Lunney, C. A. Urquhart, and P. Reed.) pp. 9–31. (NSW National Parks & Wildlife Service: Sydney.)

Reside, A. E., Welbergen, J. A., Phillips, B. L., Wardell-Johnson, G. W., Keppel, G., Ferrier, S., Williams, S. E., and VanDerWal, J. (2014). Characteristics of climate change refugia for Australian biodiversity. Austral Ecology 39, 887–897.
Characteristics of climate change refugia for Australian biodiversity.CrossRef |

Rolls, E. C. (1981). ‘A Million Wild Acres: 200 Years of Man and an Australian Forest.’ (Nelson.)

Santika, T., McAlpine, C., Lunney, D., Wilson, K., and Rhodes, J. (2014). Modelling species distributional shifts across broad spatial extents by linking dynamic occupancy models with public-based surveys. Diversity & Distributions 20, 786–796.
Modelling species distributional shifts across broad spatial extents by linking dynamic occupancy models with public-based surveys.CrossRef |

Seabrook, L., McAlpine, C., Baxter, G., Rhodes, J., Bradley, A., and Lunney, D. (2011). Drought-driven change in wildlife distribution and numbers: a case study of koalas in south west Queensland. Wildlife Research 38, 509–524.
Drought-driven change in wildlife distribution and numbers: a case study of koalas in south west Queensland.CrossRef |

Smith, A. G., McAlpine, C. A., Rhodes, J. R., Lunney, D., Seabrook, L., and Baxter, G. (2013a). Out on a limb: habitat use of a specialist folivore, the koala, at the edge of its range in a modified semi-arid landscape. Landscape Ecology 28, 415–426.
Out on a limb: habitat use of a specialist folivore, the koala, at the edge of its range in a modified semi-arid landscape.CrossRef |

Smith, A. G., McAlpine, C., Rhodes, J., Seabrook, L., Lunney, D., and Baxter, G. (2013b). Are there habitat thresholds in koala occupancy in the semiarid landscapes of the Mulgalands Bioregion? Wildlife Research 40, 413–426.

Stafford Smith, M., and McAllister, R. R. J. (2008). Managing arid zone natural resources in Australia for spatial and temporal variability – an approach from first principles. The Rangeland Journal 30, 15–27.
Managing arid zone natural resources in Australia for spatial and temporal variability – an approach from first principles.CrossRef |

State Forests of NSW (2000). NSW Western Regional Assessments. Disturbance History Mapping Project. Resource and Conservation Assessment Council of NSW, Sydney.

Stewart, J. R., Lister, A. M., Barnes, I., and Dalén, L. (2010). Refugia revisited: individualistic responses of species in space and time. Proceedings of the Royal Society of London. Series B, Biological Sciences 277, 661–671.
Refugia revisited: individualistic responses of species in space and time.CrossRef |

TRCD (2004). Brigalow Belt South Joint Vegetation Mapping Project. Resource and Conservation Assessment Council of NSW, The Resource and Conservation Division, Sydney.

TSSC (2012a). Koalas – Advice to the Minister for Sustainability, Environment, Water, Population and Communities on amendments to the list of Threatened Species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). Threatened Species Scientific Committee, Department of Sustainability, Environment, Water, Population and Communities, Canberra. Available at: http://www.environment.gov.au/biodiversity/threatened/species/pubs/koala.pdf [accessed 27 May 2017].

TSSC (2012b). Update on information relating to status of the koala since listing advice provided to Minister on 30 September 2010 and incorporating outcomes of the Senate inquiry. Threatened Species Scientific Committee, Department of Sustainability, Environment, Water, Population and Communities, Canberra. Available at: http://www.environment.gov.au/biodiversity/threatened/species/pubs/197-update-post-senate-inquiry.pdf [accessed 27 May 2017].

van Kempen, E. (1997). ‘A History of the Pilliga Cypress Pine Forests.’ (State Forests of New South Wales: Sydney.)



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