The Organization for Tropical Studies (OTS) – established almost 50 years ago – represents a consortium of almost 60 universities and colleges. The University of Michigan was one of the founding members of OTS, taking a leadership role in developing research and educational opportunities in the tropics in the 1950s and 1960s. In this seminar, Losos will also briefly discuss roles played by OTS and the University of Michigan in the development of discipline of tropical biology. Dr. Losos will then present data from multi-decadal ecological studies of trees, lizards, frogs, and birds at OTS’ La Selva Biological Station, Costa Rica. Findings from these long-term studies reveal dramatic and surprising directional changes are underway in this well-studied, old-growth neotropical forest. The causes of such changes are still poorly understood, but it is clear that they are multiple and interacting, including land-use change, climate change, predator release, and pesticide use. She will then briefly compare findings from La Selva with those from three other Neotropical biological stations in Panama, Brazil, and Peru.