ORIGINAL PAPER A preliminary investigation into the scavenging activity on pig carcasses in Western Australia R. Christopher O’Brien Æ Shari L. Forbes Æ Jan Meyer Æ Ian R. Dadour Accepted: 4 December 2006 / Published online: 7 August 2007 Ó Humana Press Inc. 2007 Abstract Human remains exposed to an outdoor envi- ronment are subject not only to the process of decompo- sition, but also to the activity of scavenging fauna. The scavenging behavior of fauna can vary considerably with region and season, affecting the rate of decomposition, and more importantly, the accuracy of postmortem interval estimations. A thorough knowledge of the scavenging behavior of fauna present in the local environment is imperative for law enforcement and forensic investigators dealing with decomposed remains located outdoors. This study was conducted to identify the major scavengers of decomposing remains in the southwest region of Western Australia. Avian species were identified as the dominant scavengers amongst a range of birds, reptiles, mammals, and amphibians feeding on cadaveric tissues and associated insects. The scavenging behavior of the fauna varied with seasonal factors, including temperature and rainfall. The preliminary results are useful for forensic investigations involving decomposed remains in the southwest region of Western Australia. Keywords Forensic taphonomy Á Scavenging activity Á Decomposition Á Fauna Á Western Australia Although there is an abundance of published material reporting on animal scavenging of both human and animal remains, there is a scarcity of field studies that have investigated region-specific animal scavenging of carcasses in outdoor environments. During the process of postmortem soft-tissue decompo- sition [1], feeding on the body can occur by a host of pre- dators including microorganisms [2], insects and other arthropods [3], and vertebrates [4], causing extensive dam- age to both soft and hard tissue that may be mistaken for postmortem trauma [5]. A better understanding of region- specific animal scavenging can assist the forensic expert in recognizing damage likely to be produced by scavengers [6], thus allowing them to make a more-informed assessment of any trauma associated with skeletal remains. In a forensic context, the modification of human remains by animal scavenging can not only distinctly mark the skeleton but also significantly affect the rate of decompo- sition and pattern of insect succession, leading to serious implications for estimations of time since death [6]. Given the variation in the impact of different species upon decomposed remains, the need for region-specific scav- enging studies to provide forensic investigators with re- gion-specific data is clearly apparent. This study was conducted to investigate the scavenging and disarticulation patterns of mammalian remains by native fauna in the southwest region of Western Australia. To date, there is no published data on scavenging by native or feral species in this area. Although there are no native species of large carnivores in Australia, (the dingo, Canis lupus dingo, the only seminative, large Australian mammalian carnivore [7] does not naturally inhabit this ecosystem) there are numerous mammals, reptiles, and birds which inhabit the southwest region, which are likely predators of carrion. The aim of this study was to identify those animals that feed R. C. O’Brien (&) Á I. R. Dadour Centre for Forensic Science, University of Western Australia, Mail Bag M420, 35 Stirling Highway, Crawley, WA 6009, Australia e-mail: chris.obrien@uwa.edu.au R. C. O’Brien Á J. Meyer School of Anatomy & Human Biology, University of Western Australia, Crawley, WA, Australia S. L. Forbes Faculty of Science, University of Ontario Institute of Technology, Oshawa, ON, Canada L1H 7K4 Forensic Sci Med Pathol (2007) 3:194–199 DOI 10.1007/s12024-007-0016-3