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RESEARCH ARTICLE
Contents Vol 35(4)

Some human, aircraft and animal factors affecting aerial surveys: how to enumerate animals from the air

Peter J. S. Fleming A B and John P. Tracey A
+ Author Affiliations
- Author Affiliations

A Vertebrate Pest Research Unit, NSW Department of Primary Industries, Orange Agricultural Institute, Forest Road, Orange, NSW 2800, Australia.

B Corresponding author. Email:peter.fleming@dpi.nsw.gov.au

Wildlife Research 35(4) 258-267 https://doi.org/10.1071/WR07081
Submitted: 3 July 2007  Accepted: 21 February 2008   Published: 27 June 2008

Abstract

Aerial surveys of wildlife involve a noisy platform carrying one or more observers moving over animals in order to quantify their abundance. This simple-sounding system encapsulates limits to human visual acuity and human concentration, visual attention, salience of target objects within the viewed scene, characteristics of survey platforms and facets of animal behaviours that affect the detection of animals by the airborne observers. These facets are too often ignored in aerial surveys, yet are inherent sources of counting error. Here we briefly review factors limiting the ability of observers to detect animals from aerial platforms in a range of sites, including characteristics of the aircraft, observers and target animals. Some of the previously uninvestigated limitations identified in the review were studied in central and western New South Wales, showing that inaccuracies of human memory and enumeration processes are sources of bias in aerial survey estimates. Standard protocols that minimise or account for the reviewed factors in aerial surveys of wildlife are recommended.


Acknowledgements

Special thanks to Brian Lukins for assisting with aerial surveys and discussions on memory and for drawing Fig. 1. Ken England and Glen Walker assisted with aerial surveys at Coolah. The work at Coolah was funded by Wildlife and Exotic Disease Preparedness and National Feral Animal Control Programs, and the Warrego study was part-funded by the Invasive Animal Cooperative Research Centre. The assistance of Mike, Chris and Ant Martin, Doug and Don Arnott, and Kevin Cluff, and the comments of two anonymous referees are appreciated.


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