The Scavenging Behaviour of the Australian Raven (Corvus Coronoides): Patterns and Influencing Factors

The Australian Raven (Corvus coronoides) is a widespread, abundant corvid which is often considered a pest species, due to the thought that it predates on livestock, ruin crops, and is often seen feeding on refuse, in both urban and rural areas. The species is known to feed on a range of material from seeds in ploughed fields to human refuse and decomposing organic material. A large proportion of its diet consists of carrion, and as such, the Australian Raven is an effective detrivorous species capable of removing and consuming dead and decomposing carcasses. This research examined the scavenging pattern of the Australian Raven on domestic pig (Sus scrofa) carcasses at four different locations surrounding Perth, Western Australia. Domestic pig carcasses were sacrificed and placed in outdoor environments and the carcasses were filmed using infrared cameras with time lapse image capture. The number of feeding events, length of feeding, material being fed upon, and associated weather data were recorded. Furthermore, the influences of location, season and life cycle of the Australian Raven on scavenging behaviour is examined. It was found that raven scavenging intensity was greatest during spring and as an omnivore there was significantly higher feeding on both flesh and insects in one event than either material on its own

The Scavenging Behaviour of the Australian Raven (Corvus Coronoides): Patterns and Influencing Factors

The Australian Raven (Corvus coronoides) is a widespread, abundant corvid which is often considered a pest species, due to the thought that it predates on livestock, ruin crops, and is often seen feeding on refuse, in both urban and rural areas. The species is known to feed on a range of material from seeds in ploughed fields to human refuse and decomposing organic material. A large proportion of its diet consists of carrion, and as such, the Australian Raven is an effective detrivorous species capable of removing and consuming dead and decomposing carcasses. This research examined the scavenging pattern of the Australian Raven on domestic pig (Sus scrofa) carcasses at four different locations surrounding Perth, Western Australia. Domestic pig carcasses were sacrificed and placed in outdoor environments and the carcasses were filmed using infrared cameras with time lapse image capture. The number of feeding events, length of feeding, material being fed upon, and associated weather data were recorded. Furthermore, the influences of location, season and life cycle of the Australian Raven on scavenging behaviour is examined. It was found that raven scavenging intensity was greatest during spring and as an omnivore there was significantly higher feeding on both flesh and insects in one event than either material on its own

A Biological and Procedural Review of Forensically Significant Dermestes Species (Coleoptera: Dermestidae)

The analyses of the insect species found on decomposing remains may provide useful information for the estimation of the minimum time elapsed since death and other parameters, such as causes and circumstances of death. The majority of research has focused on the early colonizing species, typically blowflies, while research concerning late colonizing insects is currently sparse. Dermestid beetles of the genus Dermestes L. (Coleoptera: Dermestidae) are one of the predominant insect species associated with decomposing remains during dry decay and skeletal stages of decomposition. In some dry environments, Dermestes species are likely to be the only necrophagous insects feeding on the decomposing remains. Furthermore, Dermestes species (immature and adults), their remains (cast skins and fecal material), and their artifacts (pupal chambers) are frequently found associated with ancient remains (e.g., mummies, fossils). Dermestes species have a worldwide distribution and are considered important in decomposition processes, forensic investigations, and economically as a known pest of stored products. Despite their recognized forensic importance, there is limited data documenting the ecology, biology, and the growth rates of the forensically relevant species. The aim of this review is to provide a comprehensive synopsis on the available literature concerning Dermestes species associated with forensic cases. In particular, aspects of colonization behavior, growth rates for forensic taxa and potential best practice guidelines for forensic casework encompassing late colonizing Dermestes species are discussed

The use of insects and associated arthropods in legal cases : a historical and practical perspective

 Forensic entomology has generally been recognised among law enforcement and the wider community as a science employed in the estimation of time since death. The utility of this science in contributing to the provision of time frames resulting in the focusing of valuable investigative resources has certainly been of the greatest importance. However, arthropods have been exploited extensively for their ability to provide information in a multitude of other situations, including cases of neglect, the food industry, and information relating to the cause and manner of death. This chapter will discuss the realm of information obtainable from insects and related groups in the forensic context, including and beyond the recognised time since death applications. Two areas of current research, molecular forensic entomology and entomotoxicology, will be discussed for their potential impact in the field

Mitochondrial DNA cytochrome oxidase I gene : potential for distinction between immature stages of some forensically important fly species (Diptera) in western Australia

Forensic entomology requires the fast and accurate identification of insects collected from a corpse for estimation of the postmortem interval (PMI). Identification of specimens is traditionally performed using morphological features of the insect. Morphological identification may be complicated however by the numerical diversity of species and physical similarity between different species, particularly in immature stages. In this study, sequencing was performed to study the mitochondrial DNA (mtDNA) as the prospective basis of a diagnostic technique. The sequencing focused on a section of the cytochrome oxidase I encoding region of mtDNA. Three species of calliphorid (blow flies) commonly associated with corpses in western Australia, Calliphora dubia, Chrysomya rufifacies and Lucilia sericata, in addition to specimens of Calliphora augur and Chrysomya megacephala were studied. Phylogenetic analysis of data revealed grouping of species according to genus. The DNA region sequenced allowed identification of all species, providing high support for separation on congeneric species. Low levels of variation between some species of the same genus however indicate that further sequencing is required to locate a region for development of a molecular-based technique for identification

Domestic Filth Flies in New Haven, Connecticut: A Case Study on the Effects of Urbanization and Climate Change by Comparing Fly Populations after 78 Years

Changes in common and widespread insect populations such as the domestic filth fly in urban cities are useful and relevant bioindicators for overall changes in the insect biomass. The current study surveyed necrophagous flies by placing a weekly trap from June–September over a two-year period in the city of New Haven, Connecticut, to compare data on fly abundance and diversity with data collected 78 years earlier. Climate and land cover changes were also assessed in combination with the fly population for each period. The survey results suggest the domestic filth fly population is now less diverse with decreased species richness and changes in the relative abundance of species. In both surveys, 95–96% of the population was composed of only three species. The current survey data indicate the numerical dominance of Lucilia sericata has decreased, the abundance of several species, notably Lucilia coeruleiviridis, has increased, and Lucilia illustris is absent. Species that showed a significant interaction with temperature in the 1940s survey have now increased in abundance, with several of the trapped species continuing to show an interaction with temperature and rainfall. Analysis of the land cover and climate data characterizes the trap site as a region exposed to a prolonged period of industrialization and urbanization, with only 7% of the land cover remaining undeveloped and over 50% impervious, coupled with an increase in temperature and rainfall. This study serves as a model for changes in domestic filth fly populations and other insects in similarly highly urbanized established cities