Evidence of Altered Fire Regimes in the Western Desert Region of Australia

272 Conservation Science W. Aust. 5 (3)N.D. : 272–284 Burrows (2006) et al. Evidence of altered fire regimes in the Western Desert region of Australia N.D. BURROWS1, A.A. BURBIDGE2, P.J. FULLER3 AND G. BEHN1 1Department of Conservation and Land Management, Locked Bag 104, Bentley Delivery Centre, Bentley, Western Australia, 6983. 2Department of Conservation and Land Management, Western Australian Wildlife Research Centre, P.O. Box 51, Wanneroo, Western Australia, 6946. 33 Willow Rd, Warwick, Western Australia, 6024. SUMMARY and senescing vegetation or vast tracts of vegetation burnt by lightning-caused wildfires. The relatively recent exodus of Aboriginal people from parts of the Western Desert region of Australia has coincided with an alarming decline in native mammals INTRODUCTION and a contraction of some fire sensitive plant communities. Proposed causes of these changes, in what The Great Victoria, Gibson, Great Sandy and Little Sandy is an otherwise pristine environment, include an altered Deserts (the Western Desert) occupy some 1.6 million fire regime resulting from the departure of traditional km2 of Western Australia, of which more than 100 000 Aboriginal burning, predation by introduced carnivores km2 is managed for nature conservation. The and competition with feral herbivores. conservation reserves in the Western Desert are large, Under traditional law and custom, Aboriginal people remote and relatively undisturbed. A management option inherit, exercise and bequeath customary responsibilities for such reserves is not to intervene and allow natural to manage their traditional country. Knowledge of the processes to continue to shape the biota. However, in fire regime during an estimated 30 000 years of Aboriginal spite of the apparent relative pristine nature of these occupation of these lands and the involvement of reserves and the lack of direct European impact, a sudden Aboriginal communities in contemporary land and alarming decline in native mammals has been management are important issues to be addressed if reported (Bolton & Latz 1978, Burbidge 1985, Burbidge conservation lands are to be managed appropriately. As et al. 1988, and Burbidge & McKenzie 1989). Burbidge part of this process, Pintupi Aboriginal men were and Jenkins (1984) reported that about 33 percent of interviewed and observed in the field to obtain Western Australian desert mammals are extinct or information about their traditional use of fire and to endangered. They noted that this decline had occurred obtain their views on how country could be managed over the last 30 to 50 years. Burbidge and McKenzie with fire. Of particular interest were the reasons for (1989) have shown that all declines and extinctions have burning country and the temporal and spatial variation been restricted to native mammals with a mean adult in the size and distribution of burnt patches. This valuable body weight in the range from 35 grams to 5 500 grams but largely qualitative oral information was supplemented (the critical weight range). Three main hypotheses have with a quantitative study of fire scars in a chronological been proposed to explain the decline and in some cases, sequence of early black and white aerial photographs extinction of desert mammals; change in fire regime, and more recent satellite imagery. The study focussed predation by feral animals and competition from feral on a remote region of the Western Desert, an area from herbivores (Burbidge & Johnson 1983). The notion of which Aboriginal people living a traditional lifestyle had a changed fire regime contributing to mammal decline most recently departed. The earliest aerial photographs has some support among Western Desert Aborigines. (1953) were taken as part of a military rocket For example, Ngaanyatjarra Aborigines from the development project over an area that was occupied by Warburton area of Western Australia believe that the Aboriginal people living in a traditional manner at the mitika, or burrowing bettong (Bettongia lesueur), had time of the photography. The photography revealed a “gone to the sky because the country had not been landscape mosaic of small burnt patches of vegetation at cleaned up” (de Graaff 1976). “Clean up” is a term different stages of post-fire succession. This pattern was often used by desert Aborigines for burning the vegetation consistent with information provided by Pintupi men; (Jones 1980). Kimber (1983) reported that Pintupi that fire was used purposefully, frequently and regularly people believed that perhaps a “big bushfire” caused across the landscape for many reasons but mainly to the disappearance of the golden bandicoot (Isoodon acquire food. Analysis of satellite imagery since the early auratus). 1970s, and since the cessation of traditional burning Aborigines first arrived on the Australian continent practices, revealed that the fine-grained fire mosaic has at least 50 000 – 60 000 years ago and occupied the been obliterated in recent times and replaced by a simpler deserts of the interior by at least 30 000 years ago mosaic consisting of either vast tracts of long unburnt (Mulvaney 1975, Flood 1983, Gould 1971 & O’Connor Evidence of altered fire regimes in the Western Desert region of Australia 273 et al. 1998). They showed remarkable resilience and literature arguing that fire regimes in many Australian resourcefulness to survive in a vast expanse of scattered biomes have changed since the departure of traditional food and water resources (Tonkinson 1978). They were use of fire by Aborigines (e.g., see review by Bowman highly mobile, were able to exploit a variety of resources 1998), there is limited reliable quantitative information in different areas at different times and developed a about the scale of this change in terms of the size and detailed knowledge of the environment. distribution of burnt patches. Recent changes in the fire regime are believed to be This study aimed to document some of the ways in a direct consequence of the exodus of Aboriginal people which Western Desert Aborigines used fire and to from the desert to European settlements, missions, compare their oral evidence with fire scar information outstations and other communities (Gould 1971, de Graaf extracted from early black and white aerial photography. 1976, Latz & Griffin 1978, Kimber 1983, Saxon 1984 Importantly, this study aimed to quantify the scale of the & Burbidge 1985). Latz and Griffin (1978) postulated fire mosaic created by traditional Aboriginal burning, that Aborigines created a stable ecosystem by “burning and for the first time to our knowledge, present both the country in a mosaic pattern”. They believed that quantifiable and oral evidence of a changed fire regime mosaic burning reduced the extent and continuity of since a departure from traditional burning practices. By heavy fuels, and therefore reduced the occurrence of integrating these sources of evidence, and by studying a large, intense wildfires. They also stated that a second substantially larger area of the Western Desert (~240 effect of mosaic burning was to create a range of ‘states’ 000 ha), we build on the earlier work of Burrows and in the vegetation, from early post-fire plant communities Christensen (1990), who studied aerial photographs and to old mature patches and that such diversity of states satellite imagery of a 54 000 ha area of the Western would host a greater variety of plants and animals. Latz Desert. Knowledge of traditional Aboriginal burning (1995) observed that many of the most important food practices, especially the scale of burnt patches, would plants are only abundant in the first few years after fire. greatly assist with the formulation of appropriate fire He reported that of the twelve plants that are most management strategies for desert conservation reserves. important to desert Aborigines, five are “fire weeds”. We comment on the benefits of not only incorporating The extensive use of fire by desert Aborigines was Aboriginal knowledge into land management decisions, recorded by early explorers (e.g., Warburton 1875, Giles but of meaningfully involving Aboriginal communities 1889 and Carnegie 1898) and more recently by in decision making and on-ground management anthropologists and ecologists (e.g., Finlayson 1943, activities. Jones 1969, Calaby 1971, Gould 1971, de Graaf 1976, Tonkinson 1978, Kimber 1983, Latz 1995 and Bowman 1998). Kimber (1983) observed that Pintupi used fire METHODS in a skilful and controlled manner for many reasons, such as hunting, signalling, to “clean up” country, for The departure of Aborigines from their desert homelands ceremonies, and for fun. He provided a general started with first European contact at the end of the description of when fires were lit and the range in fire nineteenth century. Amadio and Kimber (1988) present sizes and also made some crude estimates of the a summary of European exploration and contact with proportion of country burnt and the approximate age Aborigines of the northern portion of the Western Desert since the last fire, based on information in the diaries of and also describe the movements of Aboriginal people Davidson, who explored parts of the Tanami Desert in away from their homelands and into European 1900. Latz (1995) noted that, “the judicious use of fire settlements. (by Aborigines) was, in the past, the single most important To gather information about the traditional use of aspect of the desert economy”. Recently Bird et al. (2003), fire, we decided to focus the study on a region of the working with Martu Aboriginal people of the Great Sandy Western Desert from which Aborigines had most recently Desert, have described and quantified the efficiency of departed from a more-or-less traditional lifestyle. We burning as a hunting strategy and conclude that mosaic learnt that a very remote tract of land in Western Australia burning increases the efficiency of women hunting for north of the community of Kiwirrkurra and west of Lake burrowing game but not of men hunting larger, more Mackay in Western Australia was the last homeland mobile prey.

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