Historically animals have played an important role in archaeological research as analogs of or surrogates for humans. However, many bioarchaeological signatures used to examine the effect of environmental change on humans also occur on other animals. These common indicators, when studied on domesticates and commensals, can serve as different lenses on past environmental conditions and can provide a detailed insight into the interplay between humans and other animals. Overlap and variability between species in diet or developmental stresses can be indicative of general conditions that may have affected all species, as well as the specific ecological interactions and consequences for individual species. Thus multiple species analysis is useful for identifying major environmental stressors that affected all species versus cases where humans offset stresses through modifications to environments such as changes in husbandry. In this chapter, we outline this particular multi-species approach and review its use in Oceania focusing upon analyses of stable isotopes, dental pathology, and enamel hypoplasia. Interpretive difficulties can arise from the nature of animal and human assemblages and variability in animal life histories and physiological responses to stressors. Yet the studies discussed here reveal how the multispecies approach can aid understanding of the evolving human niche, and environmental change more broadly.