| dc.description.abstract | Historically, vertebrate and invertebrate scavengers have been studied independent of one another (such as carrion being placed in carrion exclusion cages), or direct consequences of their interaction ignored (vertebrate focused research overlooking arthropod data). This investigation explored the influence of vertebrate scavengers on arthropod community composition (abundance, family richness/diversity, and functional richness/diversity). It also explored how abiotic (season, and habitat) and biotic (carrion type) factors influenced carrion fate (colonized by blow flies or consumed by vertebrate scavengers).
Vertebrate scavenger access to 181 kg carrion biomasses had the greatest increase in arthropod production. Family richness was influenced by a combination of factors, though vertebrate scavenger access to carrion increased arthropod family richness 1.1x and family diversity using the Shannon Diversity Index was only influenced by time. Functional richness remained unchanged through the study sight where diversity was 1.3x greater at the lowest carrion biomass, suggesting that larger carrion biomasses are being oversaturated with few functional groups (i.e. necrophagous arthropods).
In the perspective of relatively smaller remains (< 200 g), both season and habitat played a role in what scavenger taxon consumed or colonized which carcass type had no effect. 75% of the documented species on trail cameras were mesocarnivores and obligate scavengers which consumed 100% of carrion during the winter and 62% of carrion during summer despite having low species richness (2-5 species). Of the remaining carcasses available for arthropod activity during summer, the invasive red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae) monopolized 34%, and blow flies (e.g., Lucilia eximia and Chrysomya rufifacies (Diptera: Calliphoridae)) were only able to colonize 25%. Approximately 90% of carrion that was utilized by blow flies was co-colonized by fire ants, and subsequent production of adult blow flies experienced up to a nine-fold reduction in production compared to carcasses that were not scavenged by vertebrates or fire ants. Future research should investigate population dynamics of blow flies in systems where small carrion are being largely monopolized by vertebrates, as well as blow fly dynamics in ecosystems following large influxes of carrion, such as with Mass Mortality Events. | |
