Insect biodiversity meets ecosystem function : differential effects of habitat and insects on carrion decomposition
- Authors: Barton, Philip , Evans, Maldwyn
- Date: 2017
- Type: Text , Journal article
- Relation: Ecological Entomology Vol. 42, no. 3 (2017), p. 364-374
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- Description: 1. Ecological processes are maintained in different environments by different species performing similar functional roles. Yet, little is known about the role of the environment in shaping insect biodiversity associated with a process that is ephemeral and patchy. 2. In this study, the mass loss of carrion in response to contrasting habitat types (grassland or tree) was quantified experimentally, as well as the presence, diversity and composition of insect assemblages. Differences in insect assemblages between these two habitats were also examined. 3. It was found that the presence of insects led to a doubling in mass loss, but that grassland or tree habitat type had no effect on this process. By contrast, habitat type had a significant effect on the composition of generalist ant and beetle assemblages, but not on specialist fly assemblages. Given the colonisation of insects, carrion mass loss was negatively associated with increasing evenness of fly assemblages and increasing ant abundance. Variation in fly assemblage composition was also found to correlate with variation in carrion mass loss. 4. This study highlights the major role of habitat type in shaping the composition of generalist insects at carrion, but the minor role in affecting specialist and highly vagile insects. This complements the authors' findings that insect colonisation of carrion was critical to accelerated mass loss, and that fly assemblages were responsible for variation in this process, regardless of habitat. The present study sheds new light on the contribution of insect biodiversity to decomposition in variable environments, with consequences for carrion food webs and nutrient cycling. © 2017 The Royal Entomological Society
Necrophilous insect dynamics at small vertebrate carrion in a temperate eucalypt woodland
- Authors: Barton, Philip , Evans, Maldwyn , Pechal, Jennifer , Benbow, M. Eric
- Date: 2017
- Type: Text , Journal article
- Relation: Journal of Medical Entomology Vol. 54, no. 4 (2017), p. 964-973
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- Description: 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. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.
Invertebrate scavenging communities
- Authors: Anderson, Gail , Barton, Philip , Archer, Melanie , Wallace, John
- Date: 2019
- Type: Text , Book chapter
- Relation: Carrion Ecology and Management p. 45-69
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- Description: Invertebrate scavengers of terrestrial and aquatic carrion include a broad and enormously diverse grouping of various arthropods, nematodes, and molluscs. By far the most functionally important in terrestrial ecosystems are insects, especially the flies, with crustaceans performing this role in marine ecosystems, although a multi-trophic foodweb of numerous invertebrate taxa can be found at most carcasses in most environments. The occurrence of different taxa, and the dynamics of their colonization and various competitive interactions varies across terrestrial and aquatic realms, and is greatly influenced by geographic region, climate, habitat, season, and other biotic factors. This sub-chapter focuses on the invertebrate use of carrion in both terrestrial and aquatic ecosystems, and highlights the role of different groups of invertebrates, and the biotic and abiotic factors that influence their occurrence and succession at decaying carcasses.
Towards quantifying carrion biomass in ecosystems
- Authors: Barton, Philip , Evans, Maldwyn , Foster, Claire , Pechal, Jennifer , Bump, Joseph
- Date: 2019
- Type: Text , Journal article , Review
- Relation: Trends in Ecology and Evolution Vol. 34, no. 10 (2019), p. 950-961
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- Description: The decomposition of animal biomass (carrion) contributes to the recycling of energy and nutrients through ecosystems. Whereas the role of plant decomposition in ecosystems is broadly recognised, the significance of carrion to ecosystem functioning remains poorly understood. Quantitative data on carrion biomass are lacking and there is no clear pathway towards improved knowledge in this area. Here, we present a framework to show how quantities derived from individual carcasses can be scaled up using population metrics, allowing for comparisons among ecosystems and other forms of biomass. Our framework facilitates the generation of new data that is critical to building a quantitative understanding of the contribution of carrion to trophic processes and ecosystem stocks and flows. © 2019 Elsevier Ltd. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Philip Barton” is provided in this record**
Invasive European wasps alter scavenging dynamics around carrion
- Authors: Spencer, Emma , Barton, Philip , Ripple, William , Newsome, Thomas
- Date: 2020
- Type: Text , Journal article
- Relation: Food Webs Vol. 24, no. (2020), p.
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- Description: European wasps (Vespula germanica) have invaded parts of North and South America, Australia and New Zealand. They are opportunistic predators and scavengers that can disrupt food webs and species interactions, but their role in food webs associated with carrion is poorly understood. In this study we examined wasp abundance at 20 vertebrate carcasses in south-eastern Australia. We also collected data on the abundance of blowflies and the occurrence and behavior of vertebrate scavengers at the same carcasses. Wasps arrived within minutes of deploying fresh carcasses and were approximately 4.3 times more abundant in forest compared with grassland habitats. Wasps killed and mutilated native blowflies and may have prevented them from ovipositing on carcasses, as we subsequently found that these carcasses were devoid of fly larvae. European wasps also appeared to interfere with dingoes (Canis dingo) feeding on carcasses, based on observations from cameras showing dingoes snapping their heads in the air and then retreating from the carcasses suddenly. The other major vertebrate scavenger in the system, feral pigs (Sus scrofa), did not show similar behavioral responses. Although we observed European wasps feeding on carcasses, carcass mass loss was slow. This could be a direct result of European wasps suppressing flies and potentially excluding dingoes from accessing carcasses. We conclude that European wasps may alter the way energy flows through scavenging food webs, which could have cascading impacts on ecosystem dynamics and services, although manipulative experiments would help to further evaluate these possibilities. © 2020 Elsevier Inc.
Insect abundance patterns on vertebrate remains reveal carrion resource quality variation
- Authors: Dawson, Blake , Wallman, James , Evans, Maldwyn , Barton, Philip
- Date: 2022
- Type: Text , Journal article
- Relation: Oecologia Vol. 198, no. 4 (2022), p. 1043-1056
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- Description: 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. © 2022, The Author(s).
Responses of necrophilous beetles to animal mass mortality in the Australian Alps
- Authors: Stone, Rebecca , Bonat, Stefanie , Newsome, Thomas , Barton, Philip
- Date: 2023
- Type: Text , Journal article
- Relation: Journal of Insect Conservation Vol. 27, no. 6 (2023), p. 865-877
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- Description: A diversity of insects can be found at the remains of dead animals (carrion) and they play a vital role in its decomposition and recycling. An emerging global problem with carrion is animal mass mortality events – the sudden, rapid die-off of many animals resulting in a large increase to the localised carrion resource pool. Yet, little is known about how insects respond to sudden and large inputs of carrion. We conducted an experiment in a mountainous alpine region of south-eastern Australia and compared beetle assemblages found at single carcass and mass mortality sites. We also examined the effects of vertebrate exclusion, and decomposition stage on beetles. We found 4,774 beetles representing 146 different species/morphospecies from 17 families. The most abundant species was Saprinus cyaneus cyaneus (Histeridae), and species of Staphylinidae and Silphidae also dominated the fauna, which is typical for necrophilous beetles in Australia. We also found a clear temporal change in beetle assemblages, with abundance and richness peaking during the active decay stage. We found that beetle abundance was greater at single carcasses than mass mortality sites, possibly as an artifact of sampling, and that species richness was similar among these two carcass treatment types. We found no significant effect of vertebrate exclusion on beetles, suggesting that large scavengers in the study system may not influence necrophilous insect communities around carrion. Implications for insect conservation: Our study highlights the diversity of beetles that can be found at carrion and their similar composition to the fauna found in other areas in the south-east of the Australian continent. Beetles may have reduced abundance at mass mortality sites which could affect their ability to contribute to carrion removal relative to smaller carrion quantities. Further research is required to quantify the role of other insects in carrion removal under a range of natural and mass mortality scenarios. © 2023, The Author(s).