The earth’s ecosystems comprise millions of species and underpin the well-being of all human societies. Knowledge is our strongest tool to ensure the future of life on our planet, yet much of the natural world remains poorly known and unexplored. CI’s Rapid Assessment Program (RAP) works to fill this void, sending teams of experts into critically important field sites around the world. Reliable, standardized and replicable methodologies for quickly assessing key ecosystem values in the field are essential for conservation planning and decision-making at the local to regional scale at which most threats occur. Rapid biological assessments are a cost-effective solution to this problem, providing data in a timely manner to address a wide range of conservation needs, and in particular to establish a baseline that can be used to detect changes over time.