Delayed insect access alters carrion decomposition and necrophagous insect community assembly

Vertebrate carrion in terrestrial ecosystems is an unpredictable, ephemeral resource pulse that contributes to local biodiversity and nutrient transformation dynamics. Carrion ecology is infrequently studied compared to other decomposition systems, such as leaf litter detritus, despite its importance as a resource subsidy in most ecosystems. We hypothesized that delayed insect access to carrion ( insects excluded for five days) would demonstrate marked shifts in necrophagous insect community structure, turnover rates and assembly with overall effects on carrion decomposition. Despite similarities between taxon arrival patterns, once insects were allowed to colonize carrion previously excluded from insects there was an increased necrophagous insect taxon richness and increased community turnover rates. Additionally, during the first five days of decomposition, insect exclusion carcasses remained in bloat stage while those naturally colonized were well advanced in active decomposition. This resulted in substantial differences in decomposition and highlighted the importance of insect community assembly in the decomposition process. Carrion decomposition has been a neglected field of study compared to other organic matter processes (e.g., leaf detritus), and these data suggest the ecology of carrion-arthropod interactions can contribute to a broader understanding of decomposition processes and ecosystem function.