Differential responses of scavenging arthropods and vertebrates to forest loss maintain ecosystem function in a heterogeneous landscape

Forest loss and degradation can impact on ecosystem functions. Decomposition of vertebrate carcasses is an important ecosystem function in forests, and burying beetles and scavenging vertebrates is known to contribute to the provision of this function in forests. However, the relative importance of burying beetles and scavenging vertebrates in the removal of vertebrate carcasses has rarely been explored in terms of the impact of forest loss and degradation. Here, we experimentally placed mouse carcasses on forest floors to investigate burial and removal rates by forest animals during a 7-day period at 31 sites (natural broad-leaved forests and conifer plantations in an urban/agricultural matrix) in central Japan. Ninety-six percent of dead mice disappeared with 7 days of being placed on the forest floor. Rates of carcass disappearance increased with forest area surrounding the study sites. Field observations and camera trapping showed that two species of Nicrophorus burying beetles and six species of scavenging vertebrates contributed to the carcass burial and removal. Burial rates by beetles increased with forest area, while removal rates by vertebrates decreased with forest area. Model comparisons showed that the area of both natural forests and plantations surrounding the study sites influenced burial and removal rates. Therefore, forest loss influenced the disappearance rates of vertebrate carcasses. Different responses to forest loss between burying beetles and scavenging vertebrates could maintain the carcass burying/removing function at a landscape level.