Decomposition of human remains is a complex process impacted by many intrinsic and extrinsic factors. A less-studied extrinsic factor in forensic taphonomy are the scavengers that consume soft and hard tissue. Scavengers physically degrade and remove soft tissue, disperse, and destroy skeletal elements, which can make locating remains challenging. While invertebrate activity has been largely investigated, there is limited quantitative data available on vertebrate activity, particularly in Canada. This study aimed to determine which species (vertebrate and invertebrate) belong to the scavenger guilds in southern Quebec, and their potential taphonomic impact on the decomposition process. Two independent trials were conducted in 2020 using pig carcasses: one during summer in a forest habitat and one during fall in a grassland habitat. Each carcass was placed a minimum 100 m apart in semi-rural land. Vertebrate scavenger activity was recorded by continuous surveillance using trail cameras. Carcasses were also regularly visited to monitor the decomposition process and the activity of invertebrate scavengers. Overall, the vertebrate scavenger guilds included a narrow range of corvids, turkey vultures, coyotes, and skunks. The intensity of vertebrate scavengers was greater in the grassland habitat (fall), while the intensity of invertebrate scavengers was greater in the forest habitat (summer). With the exception of invertebrate scavengers, very few species visited during the fresh stage of decomposition, and the probability of body displacement increased as decomposition progressed. These results identify which scavengers have the greatest taphonomic impact and highlight the importance of incorporating scavenger impact when searching for human remains.

While forensic science is generally focused on associating a trace to its source, trace's relevance is best addressed at the activity responsible for its genesis. Recurring studies show the potential of the Bayesian approach in order to address activity level's propositions in a rational and transparent manner. The objective of this research is to identify and review literature and models for transfer traces to create a relevant database for activity level interpretation. As of December 17 th , 2020, a thorough review of 2042 existing peerreviewed publications and studies concerning transfer traces has been conducted. The data have been classified by different criteria such as, the type of trace, year of publication, and type of study (i.e. population). Every publication has been critically analyzed according to its relevance, among others, with regards to a Canadian environment. This process identified research that needed to be completed. A database collecting publication and data on activity level assessment has been created. This database is available for consultation to laboratories, police agencies, lawyers and universities, thus contributing to the transparency of the expert opinion. RÉSUMÉ Alors que la science forensique se concentre g en eralement sur l'association d'une trace a sa source, la pertinence se situe plus g en eralement au niveau de l'activit e responsable de sa gen ese. Des etudes r ecurrentes montrent le potentiel de l'approche bay esienne afin d'aborder les propositions au niveau de l'activit e de mani ere rationnelle et transparente. L'objectif de cette recherche est d'identifier et d'analyser la litt erature concernant les traces de transfert afin de cr eer une base de donn ees pertinente pour l'interpr etation au niveau de l'activit e. En date du 17 d ecembre 2020, une analyse de 2042 etudes existantes concernant les traces de transfert a et e effectu ee. Les donn ees ont et e class ees selon diff erents crit eres tels que le type de trace, l'ann ee de publication et le type d' etude (p.ex. population). Chaque publication a fait l'objet d'une analyse critique en fonction de sa pertinence par rapport, entre autres, a l'environnement canadien. Ce processus a permis d'identifier des recherches a compl eter.

While forensic science is generally focused on associating a trace to its source, trace's relevance is best addressed at the activity responsible for its genesis. Recurring studies show the potential of the Bayesian approach in order to address activity level's propositions in a rational and transparent manner. The objective of this research is to identify and review literature and models for transfer traces to create a relevant database for activity level interpretation. As of December 17 th , 2020, a thorough review of 2042 existing peer-reviewed publications and studies concerning transfer traces has been conducted. The data have been classified by different criteria such as, the type of trace, year of publication, and type of study (i.e. population). Every publication has been critically analyzed according to its relevance, among others, with regards to a Canadian environment. This process identified research that needed to be completed. A database collecting publication and data on activity level assessment has been created. This database is available for consultation to laboratories, police agencies, lawyers and universities, thus contributing to the transparency of the expert opinion. RÉSUMÉAlors que la science forensique se concentre g en eralement sur l'association d'une trace a sa source, la pertinence se situe plus g en eralement au niveau de l'activit e responsable de sa gen ese. Des etudes r ecurrentes montrent le potentiel de l'approche bay esienne afin d'aborder les propositions au niveau de l'activit e de mani ere rationnelle et transparente. L'objectif de cette recherche est d'identifier et d'analyser la litt erature concernant les traces de transfert afin de cr eer une base de donn ees pertinente pour l'interpr etation au niveau de l'activit e. En date du 17 d ecembre 2020, une analyse de 2042 etudes existantes concernant les traces de transfert a et e effectu ee. Les donn ees ont et e class ees selon diff erents crit eres tels que le type de trace, l'ann ee de publication et le type d' etude (p.ex. population). Chaque publication a fait l'objet d'une analyse critique en fonction de sa pertinence par rapport, entre autres, a l'environnement canadien. Ce processus a permis d'identifier des recherches a compl eter.

No abstract