Dynamics of heterotrophic succession in carrion arthropod assemblages: discrete seres or a continuum of change?

Decomposition and insect succession on human cadavers in a humid, continental (Dfb) climate (Quebec, Canada)

Forensic entomology has been developing globally for decades. Despite this discipline being used in criminal investigations around the world, only a few controlled studies have been performed on human cadavers in human decomposition facilities, with the majority of these being conducted in warm and often dry climates. Therefore, the purpose of our research was to catalogue the first published data on insects associated with decomposed human bodies in a humid, continental (Dfb) climate. Specifically, our objective was to document the diversity and succession of the entomofauna associated with human cadavers throughout the decomposition process, in the Quebec province of Canada, during the summer season. Two human cadavers were studied in 2020 at the site for Research in Experimental and Social Thanatology, REST, located in Bécancour (Quebec, Canada). Insects (and other arthropods) were regularly sampled by visual observations, collection from the cadavers, and by using an entomological net and pitfall traps. Our results highlight that the decomposition process is a heterogeneous and complex process in Quebec, with cadavers showing signs of precocious desiccation/mummification. In addition, our observations confirm that the presence of superficial skin lesions accelerates the colonization of blow flies (Diptera: Calliphoridae) and, consequently, the process of decomposition. Finally, we were able to discriminate between "early colonizers" (e.g., Calliphoridae Lucilia sp. or Calliphora livida), "late colonizers" (e.g., larvae of Piophilidae or Heleomyzidae), and "non-specific colonizers." We also officially report the first observation of Cochliomyia macellaria (Diptera: Calliphoridae) in Quebec. These findings will provide new information to help medico-legal death investigations by determining the minimum time elapsed since death and the circumstances surrounding death.

Analysis of Postmortem Intestinal Microbiota Successional Patterns with Application in Postmortem Interval Estimation

Microorganisms play a vital role in the decomposition of vertebrate remains in natural nutrient cycling, and the postmortem microbial succession patterns during decomposition remain unclear. The present study used hierarchical clustering based on Manhattan distances to analyze the similarities and differences among postmortem intestinal microbial succession patterns based on microbial 16S rDNA sequences in a mouse decomposition model. Based on the similarity, seven different classes of succession patterns were obtained. Generally, the normal intestinal flora in the cecum was gradually decreased with changes in the living conditions after death, while some facultative anaerobes and obligate anaerobes grew and multiplied upon oxygen consumption. Furthermore, a random forest regression model was developed to predict the postmortem interval based on the microbial succession trend dataset. The model demonstrated a mean absolute error of 20.01 h and a squared correlation coefficient of 0.95 during 15-day decomposition. Lactobacillus, Dubosiella, Enterococcus, and the Lachnospiraceae NK4A136 group were considered significant biomarkers for this model according to the ranked list. The present study explored microbial succession patterns in terms of relative abundances and variety, aiding in the prediction of postmortem intervals and offering some information on microbial behaviors in decomposition ecology.

Carrion flies (Insecta: Diptera) found on human cadavers in Chiba prefecture, Honshu, Japan, with the first record of Fannia prisca from a human corpse

Forensic entomology (FE) involves the collection and analysis of necrophagous insects and arthropods for postmortem interval estimation based on their growth and succession. In Japan, research on FE is limited, and the predominant species of necrophagous insects and their distribution have not been clarified. The present study aimed to clarify the actual situation of insects, targeting Diptera collected from human cadavers, in Chiba Prefecture. We targeted the cases for which specimens could be collected from forensic autopsies conducted at the Legal Medicine Department of Chiba University Graduate School of Medicine or from human bodies handled by the Chiba Police in 2019. We specifically chose cases from which adult insects could be bred. Fifty cases were applicable, and 47 cases were successful in rearing adult flies. Sixteen species of Diptera were identified: six species of Calliphoridae, four species of Sarcophagidae, and a few species of Fanniidae, Muscidae, Phoridae, Piophilidae, and Stratiomyidae. The most frequently observed species were Lucilia sericata (20 cases) and Chrysomya pinguis (18 cases). For the first time, globally, we recorded the presence of Fannia prisca in a human cadaver. In conclusion, this is the first report to reveal the presence of carrion flies in human death cases in Chiba Prefecture, Japan. Research in FE is important in the context of the Japanese natural and social environment since this can aid forensic investigations conducted by authorities.

Insect abundance patterns on vertebrate remains reveal carrion resource quality variation

Resource quality is a key driver of species abundance and community structure. Carrion is unique among resources due to its high nutritional quality, rapidly changing nature, and the diverse community of organisms it supports. Yet the role resource quality plays in driving variation in abundance patterns of carrion-associated species remains poorly studied. Here we investigate how species abundances change with a measure of resource change, and interpret these findings to determine how species differ in their association with carrion that changes in quality over time. We conducted field succession experiments using pigs and humans over two winters and one summer. We quantified the effect of total body score, an objective measure of resource change, on adult insect abundance using generalised additive models. For each species, phases of increasing abundance likely indicated attraction to a high-quality resource, and length of abundance maxima indicated optimal oviposition and feeding time. Some species such as the beetle Necrobia rufipes had a rapid spike in abundance, suggesting a narrow window of opportunity for carrion resource exploitation, while species like the wasp Nasonia vitripennis had a gradual change in abundance, indicating a wide window of resource exploitation. Different abundance patterns were also observed between species occurring on pigs and humans, suggesting cadaver type is an important aspect of resource quality. Our findings show that species abundances, unlike species occurrences, can reveal additional detail about species exploitation of carrion and provide information about how resource quality may drive competition and variation in insect community succession.

How does mass loss compare with total body score when assessing decomposition of human and pig cadavers?

Providing accurate and reliable measures of decomposition is paramount for forensic research where decomposition progress is used to estimate time of death. Mass loss is routinely used as a direct measure of biomass decomposition in ecological studies, yet few studies have analysed mass loss in a forensic context on human cadavers to determine its usefulness for modelling the decomposition process. Mass loss was examined in decomposing human and pig cadavers, and compared with other common decomposition metrics, such as total body score (TBS). One summer and one winter field decomposition experiment was conducted using human and pig cadavers, as pigs are often used as proxies for human cadavers in forensic research. The two measures of decomposition revealed two contrasting patterns of decomposition on pigs and humans, particularly in winter where TBS stabilised at similar values, but mass loss differed greatly. Mass loss was found to be faster in pigs than humans during early decomposition. Pigs lost 75% of their mass in winter, while humans lost less than 50%; however, in summer, both lost around 80% of their mass. TBS displayed similar patterns in both experiments, with TBS increasing more rapidly in pigs compared with humans but both eventually reaching similar TBS values in late decomposition. Measuring mass loss can provide additional information about decomposition progress that is missed if using TBS only. Key differences in decomposition progress between cadaver types were also observed, suggesting caution when extrapolating data from pigs to humans for forensic research and decomposition modelling.

Assemblages of Acari in shallow burials: mites as markers of the burial environment, of the stage of decay and of body-cadaver regions

The burial of a cadaver results in reduced arthropod activity and disruptions in colonisation patterns. Here, the distribution and diversity of mite taxa was studied across decomposition stages of shallowly buried pig carcasses (Sus scrofa domesticus). In total 300 mites (88 species) were collected from three pig shallow graves compared to 129 mites (46 species) from control (bare) soil samples at the same depth. A successional pattern of Acari higher taxa and families was observed, and species richness and biodiversity fluctuated throughout decomposition, whereas active decay showed the greatest biodiversity. Mesostigmata mites were the most abundant in 'cadaver soils' with a significant difference in the abundance of Parasitidae mites, whereas Oribatida mites (true soil mites) were the most abundant in control soils. Certain mite species were significantly associated with decay stages: Cornigamasus lunaris with 'bloated', Gamasodes spiniger with 'active', Eugamasus sp. and Lorryia reticulata with 'advanced', and Macrocheles matrius and Ramusella clavipectinata in 'dry'. Scheloribates laevigatus was a marker of bare soil at a shallow depth and Vulgoramasus remberti of buried decomposition, not specific to any decay stage. Analysis of mite assemblages associated with head, torso and posterior body showed that Parasitus evertsi and M. matrius are attracted to beneath the thighs, whereas L. reticulata to beneath the head. This study highlights the value of mites as indicator species of decomposition and its stages, confirming (1) a succession of Acari on buried remains and (2) species specificity to body regions.

Is Resource Change a Useful Predictor of Carrion Insect Succession on Pigs and Humans?

Carrion is a dynamic and nutrient-rich resource that attracts numerous insect species that undergo succession due to the rapid change in the carrion resource. Despite this process being well-understood, few studies have examined resource change as a driver of carrion insect succession, and instead have focused on the effects of time per se, or on coarse, qualitative measures such as decay stage. Here we report on three field succession experiments using pig carcasses and human cadavers encompassing two winters and one summer. We quantified the effects of resource change (measured as total body score, TBS), carrion type, initial carrion mass, ambient temperature, and season on insect species richness and community composition. We found that all variables had an effect on different taxonomic or trophic components of the insect community composition, with the exception of initial carrion mass which had no effect. We found significant positive effects of TBS on beetle species richness and composition, while fly species richness was not significantly affected by TBS, but was by ambient temperature. TBS had a significant positive effect on all trophic groups, while ambient temperature also had a significant positive effect on the necrophages and predator/parasitoids. Our study indicates that resource change, as indicated by TBS, is an important driver of carrion insect species turnover and succession on carrion, and that TBS can provide information about insect ecological patterns on carrion that other temporal measures of change cannot.

Carcasses at Fixed Locations Host a Higher Diversity of Necrophilous Beetles

Simple Summary

Whereas vertebrate scavengers have a higher diversity reported at randomly placed carcasses, the drivers of insect diversity on carrion, such as the exposure type (fixed versus random) or the carrion species, are still incompletely understood. We analyzed beetle diversity at differently exposed carcasses in the low-range mountain forest of the Bavarian Forest National Park in Germany. We tested if scavenging beetles, similarly to vertebrate scavengers, show a higher diversity at randomly placed carcasses compared to easily manageable fixed places. Ninety-two beetle species at 29 exposed wildlife carcasses (roe, red deer, and red foxes) were detected. Beetle diversity was higher at fixed locations possessing extended highly nutrient-rich cadaver decomposition islands as important refuges for threatened red-listed species, such as Necrobia violacea (Coleoptera: Cleridae). Particularly noticeable in our insect traps were the following two rare species, the “primitive” carrion beetle Necrophilus subterraneus (Coleoptera: Agyrtidae) and the false clown beetle Sphaerites glabratus (Coleoptera: Sphaeritidae). In Europe, only the species S. glabratus out of the genus Sphaerites is present. This emphasizes the importance of carrion for biodiversity conservation. We clearly show the relevance of leaving and additional providing wildlife carcasses in a dedicated place in protected forests for preserving very rare and threatened beetle species as essential members of the decomposing community.

Abstract

In contrast to other necromass, such as leaves, deadwood, or dung, the drivers of insect biodiversity on carcasses are still incompletely understood. For vertebrate scavengers, a richer community was shown for randomly placed carcasses, due to lower competition. Here we tested if scavenging beetles similarly show a higher diversity at randomly placed carcasses compared to easily manageable fixed places. We sampled 12,879 individuals and 92 species of scavenging beetles attracted to 17 randomly and 12 at fixed places exposed and decomposing carcasses of red deer, roe deer, and red foxes compared to control sites in a low range mountain forest. We used rarefaction-extrapolation curves along the Hill-series to weight diversity from rare to dominant species and indicator species analysis to identify differences between placement types, the decay stage, and carrion species. Beetle diversity decreased from fixed to random locations, becoming increasingly pronounced with weighting of dominant species. In addition, we found only two indicator species for exposure location type, both representative of fixed placement locations and both red listed species, namely Omosita depressa and Necrobia violacea. Furthermore, we identified three indicator species of Staphylinidae (Philonthus marginatus and Oxytelus laqueatus) and Scarabaeidae (Melinopterus prodromus) for larger carrion and one geotrupid species Anoplotrupes stercorosus for advanced decomposition stages. Our study shows that necrophilous insect diversity patterns on carcasses over decomposition follow different mechanisms than those of vertebrate scavengers with permanently established carrion islands as important habitats for a diverse and threatened insect fauna.

Impact of Comingled Heterospecific Assemblages on Developmentally Based Estimates of the Post-Mortem Interval-A Study with Lucilia sericata (Meigen), Phormia regina (Meigen) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae)

Simple Summary

In forensic entomology, blow flies are often the first insects to arrive to decomposing remains. The development rates of blow flies are used to estimate the minimum amount of time between death and discovery of the remains, or post-mortem interval (PMI). When there are multiple species of flies interacting on the same remains, there could be changes in the development of the flies. We tested the development of three different species of blow flies in different combinations at different temperatures and measured the development and the rate of growth. One species (Lucilia sericata) grew larger when it developed with the species Phormia regina at certain temperatures. The larvae of Calliphora vicina gained weight slower when interacting with P. regina and P. regina grew faster when interacting with these two other species. Due to these differences in the development rates of the flies, depending on the species they are interacting with, more research is needed to further examine other species combinations and temperatures.

Abstract

Estimates of the minimum post-mortem interval (mPMI) using the development rate of blow flies (Diptera: Calliphoridae) are common in modern forensic entomology casework. These estimates are based on single species developing in the absence of heterospecific interactions. Yet, in real-world situations, it is not uncommon to have 2 or more blow fly species developing on a body. Species interactions have the potential to change the acceptance of resources as suitable for oviposition, the timing of oviposition, growth rate, size and development time of immature stages, as well as impacting the survival of immature stages to reach adult. This study measured larval development and growth rate of the blow flies Lucilia sericata (Meigen, 1826), Phormia regina (Meigen, 1826) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) over five constant temperatures (15, 20, 25, 30, 35 °C), in the presence of conspecifics or two-species heterospecific assemblages. Temperature and species treatment interacted such that L. sericata larvae gained mass more rapidly when in the presence of P. regina at 20 and 30 °C, however only developed faster at first instar. At later stages, the presence of P. regina slowed development of L. sericata immatures. Development time of C. vicina immatures was not affected by the presence of P. regina, however larvae gained mass more slowly. Development time of P. regina immatures was faster in the presence of either L. sericata or C. vicina until third instar, at which point, the presence of L. sericata was neutral whereas C. vicina negatively impacted development time. Phormia regina larvae gained mass more rapidly in the presence of L. sericata at 20 °C but were negatively impacted at 25 °C by the presence of either L. sericata or C. vicina. The results of this study indicate that metrics such as development time or larval mass used for estimating mPMI with blow flies are impacted by the presence of comingled heterospecific blow fly assemblages. As the effects of heterospecific assemblages are not uniformly positive or negative between stages, temperatures or species combinations, more research into these effects is vital. Until then, caution should be used when estimating mPMI in cases with multiple blow fly species interacting on a body.

Thermal requirements of immature stages of Chrysomya albiceps (Diptera: Calliphoridae) as a common forensically important fly

Entomological material may be used to estimate the time since death occurred (postmortem interval, PMI) in forensically obscure cases. The method that is commonly used to calculate minimum post-mortem interval (mPMI, i.e., the least amount of time since one can be confident death occurred) is based on the relationship between insect development and ambient temerature. Isomegalen and isomorphen diagrams are among methods allowing to calculate the age of necorphagous insects, yet thermal summation models provide the most precise and acurate estimations. The digrams are prepared based on the length or the developmental stages of the larvae as a function of time and mean ambient temperature. A knowledge of thermal requirements, in particular lower temperature threshold (D_z) at which development of a species terminates, is of essential importance to calculate ADD (Accumulated Degree Days). In this study different temperature regimes were used to construct the isomorphen diagram, examinate changes in larval body length at different ambient temperatures and to estimate the thermal requirements for developemnt of Chrysomya albiceps, the most common dipteran species reported on human and animal cadavers in Iran. Six development events including hatching, 1st ecdysis, 2nd ecdysis, wandering, pupariation and eclosion were studied under eleven constant temperature regims (17-37 ⁰C). The development rate of Ch. albiceps increased as temperature increased. The larval length peaked at the end of third stage and then decreased at wandering stage. The maximum larval length occurred at 72 h post oviposition at either 31, 33, or 35 °C. At 17 °C, larvae did not hatch from eggs and at 37 °C wandering larvae did not proceed to pupariation, and thus larval development were analysed at the nine left over temperatures. The development stages required at least (D_z ± SE) 13.04 ± 0.37, 14.29 ± 0.45, 15.69 ± 0.56, 15.18 ± 0.56, 14.94 ± 0.48, and 11.23 ± 0.41 °C to reach one of the successive developmentl events, respectively. The estimated thermal summation constant (k) for those the six events were 10.43 ± 0.27, 19.31 ± 0.32, 27.87 ± 1.3, 55.94 ± 1.82, 66.69 ± 3.5, and 143.52 ± 5.61 ADD accordingly.

Comparative Decomposition of Humans and Pigs: Soil Biogeochemistry, Microbial Activity and Metabolomic Profiles

Vertebrate decomposition processes have important ecological implications and, in the case of human decomposition, forensic applications. Animals, especially domestic pigs (Sus scrofa), are frequently used as human analogs in forensic decomposition studies. However, recent research shows that humans and pigs do not necessarily decompose in the same manner, with differences in decomposition rates, patterns, and scavenging. The objective of our study was to extend these observations and determine if human and pig decomposition in terrestrial settings have different local impacts on soil biogeochemistry and microbial activity. In two seasonal trials (summer and winter), we simultaneously placed replicate human donors and pig carcasses on the soil surface and allowed them to decompose. In both human and pig decomposition-impacted soils, we observed elevated microbial respiration, protease activity, and ammonium, indicative of enhanced microbial ammonification and limited nitrification in soil during soft tissue decomposition. Soil respiration was comparable between summer and winter, indicating similar microbial activity; however, the magnitude of the pulse of decomposition products was greater in the summer. Using untargeted metabolomics and lipidomics approaches, we identified 38 metabolites and 54 lipids that were elevated in both human and pig decomposition-impacted soils. The most frequently detected metabolites were anthranilate, creatine, 5-hydroxyindoleacetic acid, taurine, xanthine, N-acetylglutamine, acetyllysine, and sedoheptulose 1/7-phosphate; the most frequently detected lipids were phosphatidylethanolamine and monogalactosyldiacylglycerol. Decomposition soils were also significantly enriched in metabolites belonging to amino acid metabolic pathways and the TCA cycle. Comparing humans and pigs, we noted several differences in soil biogeochemical responses. Soils under humans decreased in pH as decomposition progressed, while under pigs, soil pH increased. Additionally, under pigs we observed significantly higher ammonium and protease activities compared to humans. We identified several metabolites that were elevated in human decomposition soil compared to pig decomposition soil, including 2-oxo-4-methylthiobutanoate, sn-glycerol 3-phosphate, and tryptophan, suggesting different decomposition chemistries and timing between the two species. Together, our work shows that human and pig decomposition differ in terms of their impacts on soil biogeochemistry and microbial decomposer activities, adding to our understanding of decomposition ecology and informing the use of non-human models in forensic research.

Impacts of antemortem ingestion of alcoholic beverages on insect successional patterns

This paper studies the impacts of antemortem ingestion of alcoholic beverages by the domestic rabbit, Oryctolagus cuniculus L., on postmortem successional patterns of insects during winter and summer 2018 in Riyadh, Saudi Arabia. Insect samples were collected from the carcasses of rabbits fed alcoholic beverages as well as untreated rabbits for 15 days postmortem during two successional studies in each season. The results showed that, during both seasons, the decomposition process for the carcasses of rabbits fed alcoholic beverages antemortem was one to two days longer. The results also showed, however, that alcoholic beverages did not affect insect succession patterns in either season. In fact, the number of insects appeared to be influenced by the ambient temperature during the two seasons, with 4415 insects in the winter compared to 1033 insects in the summer. In total, 30 insect taxa were collected during the winter study from the carcasses of rabbits fed alcoholic beverages antemortem; while 26 of these same taxa were collected from the carcasses of the untreated rabbits. Among the treated rabbits, those fed 25 ml alcoholic beverages treated attracted the highest number of insect taxa (24 taxa). In the summer study, 21 insect taxa were collected in total, 19 from the carcasses of the alcohol-treated rabbits and 13 from untreated rabbits. Among the treated rabbits, those fed 50 ml alcoholic beverages attracted the highest number of insect taxa (14 taxa). These results contribute to the understanding of the factors affecting the use of insects in medical investigations, given that alcoholic beverages are a common addictive agent.

Relative Insect Frequency and Species Richness on Sun-Exposed and Shaded Rabbit Carrions

On rabbit carcasses (Oryctolagus cuniculus L.) exposed in open and shaded habitats, the relative abundance of insects and species richness were observed. The decomposition process was classified into four stages: fresh, bloated, decayed, and dry. Except for the decayed stage, the elapsed time for each stage of decomposition was similar between open and shaded habitats, with all carcasses reaching dryness in 13 and 14 d, respectively. In total, 2009 insects were collected during the decomposition process with 1,863 flies belonging to seven families and 15 species, and 146 beetles belonging to six species and three families. Insect abundances rose between the fresh and decay stages. The dominant families of insects included Calliphoridae and Muscidae (80.9% of the collected insects) and accounting for 38.07% of the species richness, whereas Histeridae accounted for 4.3% of the collected insects and 14.29% of the species richness. The open habitat attracted 1,233 insects belonging to 18 families, including 1,142 flies and 91 beetles, whereas the shaded habitat attracted 776 insects belonging to 18 families, including 721 flies and 55 beetles. Diversity level and ratios of exclusive species are also reported for each habitat (open 61.4%; shaded 38.6%). Between habitats, there were substantially separate insect communities, however. In addition, there was a substantial difference in the insect number and species between decomposition stages. This study demonstrates that the exposure status needs to be evaluated and examined when estimating the time since death.

Succession of bacterial communities on carrion is independent of vertebrate scavengers

The decomposition of carrion is carried out by a suite of macro- and micro-organisms who interact with each other in a variety of ecological contexts. The ultimate result of carrion decomposition is the recycling of carbon and nutrients from the carrion back into the ecosystem. Exploring these ecological interactions among animals and microbes is a critical aspect of understanding the nutrient cycling of an ecosystem. Here we investigate the potential impacts that vertebrate scavenging may have on the microbial community of carrion. In this study, we placed seven juvenile domestic cow carcasses in the Grassy Mountain region of Utah, USA and collected tissue samples at periodic intervals. Using high-depth environmental sequencing of the 16S rRNA gene and camera trap data, we documented the microbial community shifts associated with decomposition and with vertebrate scavenger visitation. The remarkable scarcity of animals at our study site enabled us to examine natural carrion decomposition in the near absence of animal scavengers. Our results indicate that the microbial communities of carcasses that experienced large amounts of scavenging activity were not significantly different than those carcasses that observed very little scavenging activity. Rather, the microbial community shifts reflected changes in the stage of decomposition similar to other studies documenting the successional changes of carrion microbial communities. Our study suggests that microbial community succession on carrion follows consistent patterns that are largely unaffected by vertebrate scavenging.

Influence of Substrate Age on Oviposition Behavior of a Specialist Carrion Colonizer, Cochliomyia macellaria (Diptera: Calliphoridae)

The location and consumption of carrion by arthropods is a process that can be potentially distinguished temporally based on the makeup of the associated community. In fact, succession on carrion is a continuum of different generalist and specialist arthropods entering and leaving the system. Blow flies commonly associated with vertebrate remains are considered specialists due to their reliance on carrion as a source of food for offspring and protein for females. However, this specialization may come at a price; increased competition for resources and greater risk of local extinction. The present study examined the effects of the presence or absence of intraspecific colonization, carcass age, and exposure time on the colonization and oviposition responses of the specialist, primary colonizer, the secondary screw worm, Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae). Carcass age, exposure time, and colonization status significantly influenced the ovipositional response of C. macellaria. This species exhibited an oviposition preference for aged carcasses, with a tendency for higher oviposition after 8-h exposure time, but no preference between previously colonized or uncolonized carcasses. Mean egg hatch rate was also shown to be influenced by the aforementioned factors, with mean hatch rates varying between 81.26 and 90.97% across various treatments. These results provide insight into mechanisms driving succession on carrion, as well as highlight the variation observed in successional studies for the targeted species. Investigators relying on arthropod succession to indicate a time of colonization should proceed with caution in relying solely on the assumption primary colonizers only arrive and colonize fresh carrion.

Two human cases associated with forensic insects in Riyadh, Saudi Arabia

In Riyadh, Saudi Arabia, we are reporting two cases of natural death. The two bodies showed different types of habitat, insect colonization and decomposition stage. The first case was about the body of a 65-years-old male, with mummification of the clothed body was found in an outdoor habitat. Different life stages of Dermestes maculatus DeGeer (Coleoptera: Dermestidae were gathered from the cadaver, and due to the advanced degree of decomposition, the PMImin was estimated to be 3 months. The second body belonging to a 40-years-old male, was found in a semi-closed apartment (indoor habitat), and the body was at the end of the bloated decomposition stage. In this case, Musca domestica L. (Diptera: Muscidae) larvae were collected, and the PMImin was estimated to be 4 days. The limited insect activity for the two bodies caused by the advanced decomposition stage in the first case and indoor environment in the second. Average temperatures of (23.3 ± 1.6) °C for the first body and (27.5 ± 1.7) °C2 for the second body. Habitat was the key factor to attract insects to the two cadavers. This study stressed that, for accurate estimates of time since death, knowledge of the impact of different variables on insects found over and around the carrion is essential.

Avoidance of carnivore carcasses by vertebrate scavengers enables colonization by a diverse community of carrion insects

Carrion resources sustain a complex and diverse community of both vertebrate and invertebrate scavengers, either obligate or facultative. However, although carrion ecology has received increasing scientific attention in recent years, our understanding of carrion partitioning in natural conditions is severely limited as most studies are restricted either to the vertebrate or the insect scavenger communities. Moreover, carnivore carcasses have been traditionally neglected as study model. Here, we provide the first data on the partitioning between vertebrate and invertebrate scavengers of medium-sized carnivore carcasses, red fox (Vulpes vulpes (Linnaeus)), in two mountainous Mediterranean areas of south-eastern Spain. Carcasses were visited by several mammalian and avian scavengers, but only one carcass was partially consumed by golden eagle Aquila chrysaetos (Linnaeus). These results provide additional support to the carnivore carrion-avoidance hypothesis, which suggests that mammalian carnivores avoid the consumption of carnivore carcasses to prevent disease transmission risk. In turn, the absence of vertebrate scavengers at carnivore carcasses enabled a diverse and well-structured successional community of insects to colonise the carcasses. The observed richness and abundance of the most frequent families was more influenced by the decomposition time than by the study area. Overall, our study encourages further research on carrion resource partitioning in natural conditions.

Pigs vs people: the use of pigs as analogues for humans in forensic entomology and taphonomy research

Most studies of decomposition in forensic entomology and taphonomy have used non-human cadavers. Following the recommendation of using domestic pig cadavers as analogues for humans in forensic entomology in the 1980s, pigs became the most frequently used model cadavers in forensic sciences. They have shaped our understanding of how large vertebrate cadavers decompose in, for example, various environments, seasons and after various ante- or postmortem cadaver modifications. They have also been used to demonstrate the feasibility of several new or well-established forensic techniques. The advent of outdoor human taphonomy facilities enabled experimental comparisons of decomposition between pig and human cadavers. Recent comparisons challenged the pig-as-analogue claim in entomology and taphonomy research. In this review, we discuss in a broad methodological context the advantages and disadvantages of pig and human cadavers for forensic research and rebut the critique of pigs as analogues for humans. We conclude that experiments using human cadaver analogues (i.e. pig carcasses) are easier to replicate and more practical for controlling confounding factors than studies based solely on humans and, therefore, are likely to remain our primary epistemic source of forensic knowledge for the immediate future. We supplement these considerations with new guidelines for model cadaver choice in forensic science research.

Effects of abiotic environmental factors and land use on the diversity of carrion-visiting silphid beetles (Coleoptera: Silphidae): A large scale carrion study

Anthropogenic land use causes global declines in biodiversity. Despite the knowledge that animal carrion is the most nutrient-rich form of dead organic matter, studies on landscape and local scales determining whether and the means by which land use intensity influences the diversity of the carrion-associated insect fauna are globally scarce. We investigated the effects of land use intensity and abiotic and biotic environmental factors on the abundance, species richness, and diversity of the important ecosystem-service-providing silphid beetle taxon (carrion beetles) in three regions of Germany. In 61 forest stands distributed over three geographically distinct regions in Central Europe, we trapped silphid beetles on exposed piglet cadavers during late summer. In all three regions, higher ambient temperatures and higher fine sand contents were associated with the abundance of the silphid beetle taxa. The carrion community silphid diversity was negatively affected by an increase in mean ambient temperature in all three regions. Although management intensity in forests did not affect the overall abundance of Silphidae, the abundance of Nicrophorus humator decreased significantly with higher forest management intensity across all three regions. Unmanaged and age-class forests showed a higher abundance of N. humator compared with extensively managed forest stands. These findings indicate that N. humator has potential as an indicator species for anthropogenic disturbances in forests. Overall, the direct responses of the silphid beetle community to diverse soil characteristics underline soil as an important factor determining the abundance and diversity of necrophagous carrion beetles in Central Europe. To protect these valuable ecosystem-service providers, forest-management-induced soil modifications need to be paid close attention.

Ecological succession of adult necrophilous insects on neonate Sus scrofa domesticus in central North Carolina

The necrophilous insect fauna on carcasses varies seasonally and geographically. The ecological succession of insects arriving to decaying neonate pig carcasses in central North Carolina during late summer was sampled using a novel vented-chamber collection method. We collected six blow fly species, flesh flies, house flies and 10 beetle taxa, including four species of scarab beetles. Necrophilous fly activity dominated the early decomposition stages, whereas beetle numbers remained low until day 4. By day 7, more than 50% of the pig carcasses were skeletonized and they attracted few insects. Differences in the taxa and successional patterns documented in this experiment and a previous study in the same location highlight the ecological variation in such investigations, and underscore the need for standardization, as well as for ecological succession studies on finer geographic scales.

Is PMI the Hypothesis or the Null Hypothesis?

Over the past several decades, there have been several strident exchanges regarding whether forensic entomologists estimate the postmortem interval (PMI), minimum PMI, or something else. During that time, there has been a proliferation of terminology reflecting this concern regarding "what we do." This has been a frustrating conversation for some in the community because much of this debate appears to be centered on what assumptions are acknowledged directly and which are embedded within a list of assumptions (or ignored altogether) in the literature and in case reports. An additional component of the conversation centers on a concern that moving away from the use of certain terminology like PMI acknowledges limitations and problems that would make the application of entomology appear less useful in court-a problem for lawyers, but one that should not be problematic for scientists in the forensic entomology community, as uncertainty is part of science that should and can be presented effectively in the courtroom (e.g., population genetic concepts in forensics). Unfortunately, a consequence of the way this conversation is conducted is that even as all involved in the debate acknowledge the concerns of their colleagues, parties continue to talk past one another advocating their preferred terminology. Progress will not be made until the community recognizes that all of the terms under consideration take the form of null hypothesis statements and that thinking about "what we do" as a null hypothesis has useful legal and scientific ramifications that transcend arguments over the usage of preferred terminology.

Necrophilous Insect Dynamics at Small Vertebrate Carrion in a Temperate Eucalypt Woodland

Insects associated with carrion are critical to the decomposition process and nutrient cycling in ecosystems. Yet the communities of insects associated with carrion vary between locations, and detailed case studies are necessary for identifying differences and similarities among contrasting habitats. In this study, we examined temporal changes in the crawling insect community collected from rabbit carcasses placed in contrasting grassland and tree habitats in southeastern Australia. We collected 18,400 adult insects, including 22 species of fly, 57 species of beetle, and 37 species of ant. We found significant effects of habitat type and time, but not their interaction, on the composition of the entire insect community. Several ant species showed early and rapid colonization and highest abundances during early stages of decay, including Iridomyrmex purpureus (Smith, 1858) under trees, and Iridomyrmex rufoniger (Lowne, 1865) and Rhytidoponera metallica (Smith, 1858) in grassland. We found that most fly species showed highest abundance during active decay, but Chrysomya varipes (Macquart 1851) was more abundant under trees than in grassland during this time. Beetles peaked during active or advanced decay stages, with Saprinus and Omorgus the most abundant genera. Our study demonstrates that strong replication of contrasting environmental treatments can reveal new information on habitat preferences of important carrion insect species. The numerical dominance of ants early in decomposition has implications for insect community structure via potential competitive interactions with flies, and should be more rigorously examined in future carrion studies.

Facilitation may not be an adequate mechanism of community succession on carrion

The facilitation model of ecological succession was advanced by plant ecologists in the late 1970s and was then introduced to carrion ecology in the late 1980s, without empirical evidence of its applicability. Ecologists in both disciplines proposed removing early colonists, in this case fly eggs and larvae, from the substrate to determine whether other species could still colonize, which to our knowledge has never been attempted. Here, we tested the facilitation model in a carrion system by removing fly eggs and larvae from carcasses that were exposed in agricultural fields and assigned to one of the following treatment levels of removal intensity: 0, <5, 50, and 100%. Subsequent patterns of colonisation did not provide support for the applicability of the facilitation model in carrion systems. Although results showed, in part, that the removal of fly eggs and larvae decreased the decomposition rate of carcasses, the removal did not prevent colonization by secondary colonizers. Finally, we discuss future studies and make recommendations as to how the facilitation model could be improved, firstly by being more specific about the scale where facilitation is believed to be occurring, secondly by clearly stating what environmental modification is believed to be involved, and thirdly by disentangling facilitation from priority effects.

First Report of Necrophagous Insects on Human Corpses in Riyadh, Saudi Arabia

Necrophagous species of insects provide useful complementary data to estimate the postmortem interval in forensic cases. Here, for the first time, we report on insect specimens collected from human corpses in Riyadh, Kingdom of Saudi Arabia. During the study, 14 beetle larvae were collected from the outdoor corpse (case report one) and five flies and seven beetles were collected from the indoor corpse (case report two). Sequencing was performed to study the mitochondrial DNA (mtDNA) as the prospective basis of an identification technique. The sequencing focused on a section of the cytochrome oxidase I encoding region of mtDNA. Two beetle species, Dermestes frischii (Kugelann) and Dermestes maculatus (De Geer) (Coleoptera: Dermestidae), and one fly species, Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae), were identified. These results will be instrumental in the implementation of a Saudi database of forensically relevant insects.

Differential Diptera Succession Patterns on Decomposed Rabbit Carcasses in Three Different Habitats

This study describes for the first time the necrophagous Diptera attracted to rabbit carcasses in three distinct habitats in Riyadh, Kingdom of Saudi Arabia (KSA). A mean number of 1,427 flies belonging to 8 families and 16 species were collected during the decomposition process of the rabbits at the three different sites. Carcasses in the agricultural habitat attracted 1,146 flies from 7 families and 14 species, compared to carcasses in the urban site, which attracted 249 flies from 5 families and 9 species. Carcasses in the desert site attracted the lowest number (28 flies from 4 families and 5 species). In the agricultural and desert sites, flies were represented at all decomposition stages. Also, in the urban site, flies were represented at all stages except the fresh and dry stages. Lucilia sericata Meigen was the most abundant species occurring in both the agricultural and desert sites, while Musca domestica L. was the most abundant species occurring in the urban site. The evidence presented here, therefore, suggests that L. sericata and M. domestica are potentially useful species for estimating minimal postmortem intervals in this region of KSA.

Present and foreseeable future of metabolomics in forensic analysis

The revulsive publications during the last years on the precariousness of forensic sciences worldwide have promoted the move of major steps towards improvement of this science. One of the steps (viz. a higher involvement of metabolomics in the new era of forensic analysis) deserves to be discussed under different angles. Thus, the characteristics of metabolomics that make it a useful tool in forensic analysis, the aspects in which this omics is so far implicit, but not mentioned in forensic analyses, and how typical forensic parameters such as the post-mortem interval or fingerprints take benefits from metabolomics are critically discussed in this review. The way in which the metabolomics-forensic binomial succeeds when either conventional or less frequent samples are used is highlighted here. Finally, the pillars that should support future developments involving metabolomics and forensic analysis, and the research required for a fruitful in-depth involvement of metabolomics in forensic analysis are critically discussed.

Carrion beetles succession in three different habitats in Riyadh, Saudi Arabia

A main objective of the study is the establishment of a forensic entomological database for Riyadh, Saudi Arabia. Decomposition processes and beetle succession were analysed on rabbit carcasses in three different habitats (agricultural, desert and urban) in the period from May to July 2014. Due to the effects of the high temperature at the study sites, carrion reached the dry stage within 12 days in the agricultural habitat, and 6 days in the desert and urban habitats. A total of 125 beetles belonging to eight species and five families were collected during the decaying process, with their abundances increasing from the fresh to decay stages. The prevailing species belonged to the families of Dermestidae and Histeridae. It was not possible to confirm any definitive relationship between the occurrence of a single species and a particular stage of decomposition. The beetle communities were also not distinctively different between desert and urban habitats, but a distinct community was evident in the agriculture habitat. In addition, there were distinct beetle communities between the decay stage and the other stages. The dry stage recorded the lowest number of beetles. This study indicated that, the habitat type had an effect on the decay process and the abundance rate of the beetles.

REWRITING ECOLOGICAL SUCCESSION HISTORY: DID CARRION ECOLOGISTS GET THERE FIRST?

Ecological succession is arguably the most enduring contribution of plant ecologists and its origins have never been contested. However, we show that French entomologist Pierre Mégnin, while collaborating with medical examiners in the late 1800s, advanced the first formal definition and testable mechanism of ecological succession. This discovery gave birth to the twin disciplines of carrion ecology and forensic entomology. As a novel case of multiple independent discovery, we chronicle how the disciplines of plant and carrion ecology (including forensic entomology) accumulated strikingly similar parallel histories and contributions. In the 1900s, the two groups diverged in methodology and purpose, with carrion ecologists and forensic entomologists focusing mostly on case reports and observational studies instead of hypothesis testing. Momentum is currently growing, however, to develop the ecological framework of forensic entomology and advance carrion ecology theory. Researchers are recognizing the potential of carcasses as subjects for testing not only succession mechanisms (without assuming space-for-time substitution), but also aggregation and coexistence models, diversity-ecosystem function relationships, and the dynamics of pulsed resources. By comparing the contributions of plant and carrion ecologists, we hope to stimulate future crossover research that leads to a general theory of ecological succession.

Curatorial implications of Ophyra capensis (Order Diptera, Family Muscidae) puparia recovered from the body of the Blessed Antonio Patrizi, Monticiano, Italy (Middle Ages)

The discovery of dipteran remains on mummified individuals can lead to either cause for curatorial concern or to a better understanding of the individual's post-mortem environment. The present study analyzed insect remains associated with the body of a unique medieval mummy of religious significance, that of the Blessed Antonio Patrizi da Monticiano. A total of 79 puparia were examined and all were identified as Ophyra capensis (Diptera: Muscidae). Additionally, a desiccated moth (Lepidoptera: Tineidae) was encountered. Puparia of O. capensis would be associated with normal decomposition shortly after the death of the mummified individual, and not an infestation beginning during more recent years. Similarly, the tineid moth found would likely be related with decomposition of cloth associated with the remains. These findings illustrate how collection and identification of insects associated with human remains can distinguish between historical decomposition versus issues of modern curatorial concern.

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.

Evaluating the utility of hexapod species for calculating a confidence interval about a succession based postmortem interval estimate

Carrion insect succession patterns have long been used to estimate the postmortem interval (PMI) during a death investigation. However, no published carrion succession study included sufficient replication to calculate a confidence interval about a PMI estimate based on occurrence data. We exposed 53 pig carcasses (16±2.5 kg), near the likely minimum needed for such statistical analysis, at a site in north-central Indiana, USA, over three consecutive summer seasons. Insects and Collembola were sampled daily from each carcass for a total of 14 days, by this time each was skeletonized. The criteria for judging a life stage of a given species to be potentially useful for succession-based PMI estimation were (1) nonreoccurrence (observed during a single period of presence on a corpse), and (2) found in a sufficiently large proportion of carcasses to support a PMI confidence interval. For this data set that proportion threshold is 45/53. Of the 266 species collected and identified, none was nonreoccuring in that each showed at least a gap of one day on a single carcass. If the definition of nonreoccurrence is relaxed to include such a single one-day gap the larval forms of Necrophilaamericana, Fanniascalaris, Cochliomyia macellaria, Phormiaregina, and Luciliaillustris satisfied these two criteria. Adults of Creophilus maxillosus, Necrobiaruficollis, and Necrodessurinamensis were common and showed only a few, single-day gaps in occurrence. C.maxillosus, P.regina, and L.illustris displayed exceptional forensic utility in that they were observed on every carcass. Although these observations were made at a single site during one season of the year, the species we found to be useful have large geographic ranges. We suggest that future carrion insect succession research focus only on a limited set of species with high potential forensic utility so as to reduce sample effort per carcass and thereby enable increased experimental replication.

Contrasting diversity dynamics of phoretic mites and beetles associated with vertebrate carrion

Carrion is an ephemeral and nutrient-rich resource that attracts a diverse array of arthropods as it decomposes. Carrion-associated mites often disperse between animal carcasses using phoresy, the transport of one species by another. Yet few studies have contrasted the dynamics of mite assemblages with other insect taxa present at carrion. We examined and compared the changes in abundance, species richness and composition of mite and beetle assemblages sampled at kangaroo carcasses in a grassy eucalypt woodland at four different times over a 6-month period. We found that the majority of mites were phoretic, with the mesostigmatid genera Uroseius (Uropodidae), Macrocheles (Macrochelidae) and Parasitus (Parasitidae) the most abundant taxa (excluding astigmatid mites). Abundance and richness patterns of mites and beetles were very different, with mites reaching peak abundance and richness at weeks 6 and 12, and beetles at weeks 1 and 6. Both mites and beetles showed clear successional patterns via changes in species presence and relative abundance. Our study shows that mesostigmatid mite assemblages have a delay in peak abundance and richness relative to beetle assemblages. This suggests that differences in dispersal and reproductive traits of arthropods may contribute to the contrasting diversity dynamics of carrion arthropod communities, and further highlights the role of carrion as a driver of diversity and heterogeneity in ecosystems.

The role of spatial aggregation in forensic entomology

A central concept in forensic entomology is that arthropod succession on carrion is predictable and can be used to estimate the postmortem interval (PMI) of human remains. However, most studies have reported significant variation in successional patterns, particularly among replicate carcasses, which has complicated estimates of PMIs. Several forensic entomology researchers have proposed that further integration of ecological and evolutionary theory in forensic entomology could help advance the application of succession data for producing PMI estimates. The purpose of this essay is to draw attention to the role of spatial aggregation of arthropods among carrion resources as a potentially important aspect to consider for understanding and predicting the assembly of arthropods on carrion over time. We review ecological literature related to spatial aggregation of arthropods among patchy and ephemeral resources, such as carrion, and when possible integrate these results with published forensic literature. We show that spatial aggregation of arthropods across resources is commonly reported and has been used to provide fundamental insight for understanding regional and local patterns of arthropod diversity and coexistence. Moreover, two suggestions are made for conducting future research. First, because intraspecific aggregation affects species frequency distributions across carcasses, data from replicate carcasses should not be combined, but rather statistically quantified to generate occurrence probabilities. Second, we identify a need for studies that tease apart the degree to which community assembly on carrion is spatially versus temporally structured, which will aid in developing mechanistic hypotheses on the ecological factors shaping community assembly on carcasses.

Electrophysiological and behavioral responses of Thanatophilus sinuatus Fabricius (Coleoptera: Silphidae) to selected cadaveric volatile organic compounds

Soon after death, carcasses release volatile chemicals that attract carrion insects including Silphidae. Nevertheless, it is not known which chemical cues are involved in the attractiveness of the carcass. So far, little information is available on the chemical ecology of carrion beetles, particularly concerning the subfamily of Silphinae. The biological role of selected cadaveric volatile organic compounds including dimethyldisulfide (DMDS), butan-1-ol, n-butanoic acid, indole, phenol, p-cresol, putrescine, and cadaverine on the silphine species, Thanatophilus sinuatus Fabricius, was investigated using both electrophysiological and behavioral techniques. Among the tested cadaveric compounds, butan-1-ol and DMDS elicited the strongest electroantennography (EAG) from both T. sinuatus male and female antennae. In a two-arm olfactometer, males and females were significantly attracted to DMDS for both tested doses, whereas only males were attracted to p-cresol at 100 ng. Putrescine was repellent to males at the dose of 1 μg.

The potential use of bacterial community succession in forensics as described by high throughput metagenomic sequencing

Decomposition studies of vertebrate remains primarily focus on data that can be seen with the naked eye, such as arthropod or vertebrate scavenger activity, with little regard for what might be occurring with the microorganism community. Here, we discuss the necrobiome, or community of organisms associated with the decomposition of remains, specifically, the "epinecrotic" bacterial community succession throughout decomposition of vertebrate carrion. Pyrosequencing was used to (1) detect and identify bacterial community abundance patterns that described discrete time points of the decomposition process and (2) identify bacterial taxa important for estimating physiological time, a time-temperature metric that is often commensurate with minimum post-mortem interval estimates, via thermal summation models. There were significant bacterial community structure differences in taxon richness and relative abundance patterns through the decomposition process at both phylum and family taxonomic classification levels. We found a significant negative linear relationship for overall phylum and family taxon richness as decomposition progressed. Additionally, we developed a statistical model using high throughput sequencing data of epinecrotic bacterial communities on vertebrate remains that explained 94.4 % of the time since placement of remains in the field, which was within 2-3 h of death. These bacteria taxa are potentially useful for estimating the minimum post-mortem interval. Lastly, we provide a new framework and standard operating procedure of how this novel approach of using high throughput metagenomic sequencing has remarkable potential as a new forensic tool. Documenting and identifying differences in bacterial communities is key to advancing knowledge of the carrion necrobiome and its applicability in forensic science.

Diversity of forensic rove beetles (Coleoptera, Staphylinidae) associated with decaying pig carcass in a forest biotope

Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession. So far, little information is available on the postmortem colonization by beetles and the decomposition process they initiate under temperate biogeoclimatic countries. These beetles have, however, been referred to as being part of the entomofaunal colonization of a dead body. Forensic entomologists need increased databases detailing the distribution, ecology, and phenology of necrophagous insects, including staphylinids (Coleoptera, Staphylinidae). While pig carcasses are commonly used in forensic entomology studies to surrogate human decomposition and to investigate the entomofaunal succession, very few works have been conducted in Europe on large carcasses. Our work reports the monitoring of the presence of adult rove beetles (Coleoptera, Staphylinidae) on decaying pig carcasses in a forest biotope during four seasons (spring, summer, fall, and winter). A total of 23 genera comprising 60 species of rove beetles were collected from pig carcasses.

Species traits predict assemblage dynamics at ephemeral resource patches created by carrion

Carrion is an ephemeral and spatially patchy resource that supports a diverse subset of species linked to nutrient cycling and the decomposition process. A number of studies have separately documented changes in the diversity of plants, arthropods and vertebrates at individual carcasses, but there are few studies that have examined how functional traits of different groups of organisms underpin their responses to carrion patches. We used a carrion addition experiment to compare changes in composition and functional traits of insect and plant assemblages at carcasses compared with control sites. We found that significant changes in insect assemblage evenness and heterogeneity was associated with species’ dispersal traits, and that plant assemblage responses to subsequent soil nitrogen changes was most apparent among graminoids and exotic species. Beetles at carcasses were twice as large as their counterparts at control sites during the first week of carrion decomposition, and also had higher wing loadings. Plants with high specific leaf area responded faster to the carcass addition, and twice as many species recolonised the centre of carcasses in exotic-dominated grassland compared with carcasses in native-dominated grassland. These results provide an example of how traits of opportunist species enable them to exploit patchy and dynamic resources. This increases our understanding of how carcasses can drive biodiversity dynamics, and has implications for the way carrion might be managed in ecosystems, such as appropriate consideration of spatial and temporal continuity in carrion resources to promote heterogeneity in nutrient cycling and species diversity within landscapes.