What performs?

What might our discipline gain from decentering the human as theatre’s actor, author, and agent? What else performs? How does placing non-humans center stage expand our historiographic imagination, putting new pressure on familiar methods, and breathing new life into objects/subjects long dismissed as the inert material from which performance, and performance history, is fashioned? What new understandings of performance emerge from this effort? And how might they enrich discourse in other disciplines where "performance” is an oft-cited but little understood concept?