Development of a lightweight, portable trap for capturing free-ranging Koalas Phascolarctos cinereus
Biolink Ecological Consultants
Koalas Phascolarctos cinereus are specialised arboreal folivores that inhabit woodland and forest communities of eastern Australia (Martin and Lee 1984). The species is also Australia’s largest arboreal mammal, the weights of adult males in southeastern Australia reaching approximately 13kgs (Lee and Martin 1988). Much of the knowledge on various aspects of koala ecology has come from studies of captured animals (e.g. Gall 1976; Martin 1981; Lee et al. 1990; Mitchell 1990; Melzer and Lamb 1996; Pieters and Woodhall 1996; Kavanagh et al. 2007). Traditionally, the capture of koalas for research and/or management purposes involves various procedures, most of which employ a combination of telescopic poles, flags and/or nooses, usually in conjunction with a variable (but by no means commensurate) measure of arboreality on the part of researchers and/or their assistants. However, koala capture procedures in some areas of Australia have drawn criticism from some quarters (Phillips 1997). In New South Wales, concerns about some captures led to instigation of a formal review of procedures by the south-east forests Koala Research Committee. This review (Bali and Delaney 1996) recognised the potential for stressful captures to contribute to koala mortality and amongst other things, resulted in the development of draft capture protocols for researchers. The protocols (subsequently amended by the former NSW Koala Research Committee) have been adopted by the (now) NSW Department of Environment, Climate Change and Water and are distributed to Animal Ethics Committees in NSW for their guidance. Whilst various capture methods were reviewed by Bali and Delaney (1996), the concept of actually trapping koalas was not discussed in any detail and is therefore not one of the preferred methods recognised by the protocols. The purpose of this paper is to describe a trapping device that has proven effective in the capture of free-ranging koalas. Trap specifications and the results from a pilot study are presented herein with a view to broader acceptance of the technique as an acceptable method of koala capture that offers a number of advantages when compared to more traditional techniques.