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Ecology, management and conservation in natural and modified habitats
RESEARCH ARTICLE

Design of aerial surveys for population estimation and the management of macropods in the Northern Tablelands of New South Wales, Australia

S. C. Cairns A C , G. W. Lollback A and N. Payne B
+ Author Affiliations
- Author Affiliations

A Zoology, School of Environmental and Rural Sciences, University of New England, Armidale, NSW 23521, Australia.

B New South Wales Department of Environment and Climate Change, PO Box 2111, Dubbo, NSW 2880, Australia.

C Corresponding author. Email: scairns@une.edu.au

Wildlife Research 35(4) 331-339 https://doi.org/10.1071/WR07079
Submitted: 29 June 2007  Accepted: 20 May 2008   Published: 27 June 2008

Abstract

As part of a kangaroo management program, eastern grey kangaroos (Macropus giganteus) and common wallaroos (M. robustus robustus) are harvested from three kangaroo management zones in north-eastern New South Wales, Australia. To set sustainable harvest quotas, it is necessary to obtain reasonably accurate estimates of the sizes of the populations of these two species of macropod. Recently, this has been done on two occasions using helicopter line-transect surveys. For the most recent of these surveys, conducted in 2004, each management zone was subdivided into three strata of increasing kangaroo density and the surveys were designed in relation to this stratification using an automated survey design algorithm. The results of the surveys were that eastern grey kangaroo densities were estimated as 8.11 ± 1.81 km–2 in the Glen Innes zone, 10.23 ± 2.41 km–2 in the Armidale zone and 4.82 ± 0.87 km–2 in the Upper Hunter zone. Wallaroo densities for these three zones were 3.06 ± 0.73 km–2, 5.68 ± 3.45 km–2 and 4.40 ± 1.01 km–2 respectively. The wallaroo densities were determined by multiplying the initial estimated densities by a correction factor of 1.85. Across the three kangaroo management zones, eastern grey kangaroo densities did not change in any significant way between the two surveys. This was also the case for wallaroos in the Glen Innes and Armidale zones. Wallaroo density in the Upper Hunter zone, however, increased significantly between the two surveys. Over a decade before these surveys were conducted, a series of ground surveys using walked line-transect sampling were undertaken. The density estimates derived from the helicopter surveys proved to be broadly comparable to those derived from the ground surveys, suggesting that conducting helicopter line-transect surveys designed using the method deployed here is effective in producing population estimates for the purpose of kangaroo management.


Acknowledgements

As with any project, the job is never completed without the support of others who are either wittingly or unwittingly drawn in to provide assistance. So, in order of the support provided, thanks goes to the following people. Steve Naven of NSW DECC provided the shape files (including the initial stratification) of the three Northern Tablelands kangaroo management zones. Mark Reid of Reid Heliwork provided the survey platform and excellent and obliging service as the pilot. David Bearup and Peter Morris acted as observers during the course of the surveys. Scott Seymour contributed valuable logistical support during the surveys. Tony Pople (UQ) provided some advice with regard to distance sampling and data analysis.


References

Borchers D. L., Buckland S. T., and Zuchini W. (2002). ‘Estimating Animal Abundance: Closed Populations.’ (Springer-Verlag: London.)

Buckland S. T., Anderson D. A., Burnham K. P., Laake J. L., Borchers D. L., and Thomas L. (2001). ‘Introduction to Distance Sampling: Estimating Abundance of Biological Populations.’ (Oxford University Press: Oxford.)

Burnham, K. P. , Anderson, D. R. , and Laake, J. L. (1980). Estimation of density from line transect sampling of biological populations. Wildlife Monographs 72, 1–202.
Burnham K. P., Buckland S. T., Laake J. L., Borchers D. L., Marques T. A., Bishop J. R. B., and Thomas L. (2004). Further topics in distance sampling. In ‘Advanced Distance Sampling’. (Eds S. T. Buckland, D. A. Anderson, K. P. Burnham, J. L. Laake and L. Thomas.) pp. 307–392. (Oxford University Press: Oxford.)

Cairns S. C. (2003). Report to the New South Wales National Parks and Wildlife Service on the consultancy: Kangaroo Monitoring New England Tablelands Helicopter Survey. Unpublished report to New South Wales National Parks and Wildlife Service, Dubbo, NSW.

Clancy, T. F. (1999). Choice of survey platforms and technique for broad-scale monitoring of kangaroo populations. Australian Zoologist 31, 267–274.
Emery K. A. (1985). ‘Rural Land Capability Mapping.’ (Soil Conservation Service of NSW: Sydney.)

Fewster R. M., and Buckland S. T. (2004). Assessment of distance sampling estimators. In ‘Advanced Distance Sampling’. (Eds S. T. Buckland, D. A. Anderson, K. P. Burnham, J. L. Laake and L. Thomas.) pp. 281–306. (Oxford University Press: Oxford.)

Gilroy, J. (1999). Kangaroo monitoring in relation to the kangaroo management plan in New South Wales. Australian Zoologist 31, 306–308.
New South Wales National Parks and Wildlife Service (2001). The New South Wales Kangaroo Management Program. A management program for the utilisation of four kangaroo species in NSW. New South Wales National Parks and Wildlife Service, Sydney. Available online at http://www.environment.nsw.gov.au/resources/nature/kmp.pdf [Verified June 2008]

Pople, A. R. (2004). Population monitoring for kangaroo management. Australian Mammalogy 26, 37–44.
Pople A. R., and Grigg G. C. (1998). Commercial harvesting of kangaroos in Australia. Environment Australia, Canberra. Available online at http://www.ea.gov.au/biodiversity/trade-use/wild-harvest/kangaroo/harvesting/index.html [Verified May 2008]

Pople, A. R. , Cairns, S. C. , Menke, N. , and Payne, N. (2006). Estimating the abundance of eastern grey kangaroos (Macropus giganteus) in south-eastern New South Wales Australian Wildlife Research 33, 93–102.
Crossref | GoogleScholarGoogle Scholar | Sahukar R., Gallery C., Smart J., and Mitchell P. (2003). The Bioregions of New South Wales: their biodiversity, conservation and history. National Parks and Wildlife Service NSW, Dubbo.

Southwell, C. (1994). Evaluation of walked line transect counts for estimating densities of kangaroos. The Journal of Wildlife Management 58, 348–356.
Crossref | GoogleScholarGoogle Scholar | Strindberg S., Buckland S. T., and Thomas L. (2004). Design of distance sampling surveys and Geographic Information Systems. In ‘Advanced Distance Sampling’. (Eds S. T. Buckland, D. A. Anderson, K. P. Burnham, J. L. Laake and L. Thomas.) pp. 190–228. (Oxford University Press: Oxford.)

Taylor, R. J. (1985). Habitat use by the eastern grey kangaroo and wallaroo in an area of sympatry. Mammalia 49, 173–186.
Thomas L., Laake J. L., Strindberg S., Marques F. F. C., Buckland S. T., Borchers D. L., Anderson D. R., Burnham K. P., Hedley S. L., Pollards J. H., and Bishop J. B. R. (2003). ‘Distance 4.1. Release 2.’ (Research Unit for Wildlife Population Assessment: University of St Andrews.) Available online at www.ruwpa.st-andrews.ac.uk/distance/ [Verified May 2008]

Thomas, L. , Williams, R. , and Sandilands, D. (2007). Designing liner transect surveys for complex survey regions. Journal of Cetacean Research and Management 9, 1–11.
Thompson S. K. (2002). ‘Sampling’. 2nd edn. (John Wiley and Sons: New York.)