Terrain of taphonomy: how biogeographic variation affects decomposition and scavenger behaviour in two forensically significant habitats of Cape Town, South Africa.

Abstract

In South Africa, high rates of unidentified human remains necessitate the establishment of regionally specific high resolution taphonomic data to facilitate accurate reconstruction of postmortem circumstances and timing, as well as identification. This study investigates the effects scavenging and environmental conditions on the decomposition process using porcine models as human analogs across two distinct forensic sites in Cape Town: a suburban site and a peri-urban site. Over four deployments (July 2021-January 2023), six clothed porcine bodies were placed at each site and monitored. Data collected included mass loss, scavenger activity (notably by the Cape grey mongoose Galerella pulverulenta), and environmental variables. Findings revealed that seasonal variations and habitat types had significant impacts on the rate and pattern of decomposition. Porcine bodies at the Medical Research Council site consistently decomposed faster than those at the University of Cape Town site due to the micro habitat differences documented between the two sites. This research underscores the importance of considering biogeographic variation and the displacement of vertebrate scavengers in urban settings, emphasising the need for careful site selection in decomposition research to better reflect some forensic urban scenarios. By replicating the locally prevalent medicolegal death scenario of a single clothed body, the study enhances understanding of postmortem processes in Cape Town and contributes to the refinement of methodologies for forensic taphonomy within specific ecological contexts.