A synopsis of long-term field studies of mammals: achievements, future directions, and some advice

Long-term individual-based field studies are essential for understanding how animals are adapted to their natural environment and how they will adapt in the future. Long-term studies conducted on more than 200 mammalian species have accumulated 11,000 study years and covered more than 17,000 generations. They have been dominated by studies on social systems and population biology, with little research on ecophysiology-typically, ecophysiological studies are short-term projects embedded in long-term studies. However, physiological data are necessary for understanding how mammals respond to rapid global changes. This is especially important in conservation, for which long-term monitoring of natural populations is essential. Maintaining a successful long-term study requires an understanding of the unique life history of long-term studies. Like short-term studies, long-term studies progress from onset to end, but long-term studies differ in the way they are maintained. The greatest challenge to long-term research is the need for consistent and regular funding. Long-term research also requires principal investigators with strong organizational skills, productive collaborations, and creative ways of maintaining financial support. We address challenges and discuss strategies, some based on our own experiences, for the successful management and life history of long-term studies.