This review covers long-term ecological studies in Central America, South America, and Antarctica that include at least 10 years of data on both terrestrial and marine mammals as well as birds. Specifically, we compiled long-term research on social systems, population ecology, and community ecology. Long-term research is necessary to understand decadal trends and dynamics that would otherwise go unnoticed in short-term studies. This review highlights the impact of ecological conditions as well as territoriality and conflict on social organization and structure, the role that environmental perturbations and climate change have on populations, and how interaction between biotic and abiotic factors influence entire ecological communities. It especially highlights the need for additional long-term studies to assess climate change trends and the ecological changes that will follow.