NatureServe and its network of natural heritage programs are the leading source for information about rare and endangered species and threatened ecosystems.
Society for Conservation Biology (SCB) is an international professional organization dedicated to promoting the scientific study of the phenomena that affect the maintenance, loss, and restoration of biological diversity.
Ecological Society of America (ESA) is a nonpartisan, nonprofit organization dedicated to promoting communication between ecologists, awareness of the importance, increase resources, and more.