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

Patterns of species change, computed day to day community similarity, polar ordination, and other statistics were used to discern successional trends and correspondence with named decay stages from eleven carrion arthropod studies. The carrion arthropod community develops primarily as a continuum of gradual change: rapid at first, slow during peak activity, and erratic in the final days as carcass resources become depleted. In only five studies the ordination analysis revealed recognizable clusters representing discrete faunal seres; none of these, however, completely supported a stage-based view of faunal succession. Collectively, the authors of published studies identified 29 decay stage boundaries; of these, only 14 were associated with major faunal changes. We found at least 27 additional episodes involving compositional differences in the fauna not recorded by the authors. Named decay stages may have descriptive utility in carrion studies. However, ecologists and forensic entomologists should be alerted to the inadequacies of decay stages in summarizing patterns of faunal succession in carrion arthropod investigations.