While atypical mass strandings of beaked whales have been linked to naval exercises using mid-frequency sonar, the causal chain of events from sound exposure to stranding has not been elucidated. We now know that beaked whales react strongly to sonar, killer whale calls, and bandlimited noise by ceasing echolocation and completing an unusually slow, directional ascent, in many cases leaving the area entirely (Pirotta et al., 2012; Tyack et al., 2011). Less is known about potential risks to other species of odontocetes overlapping with navy exercises. This project is part of a collaborative research program with the goals to: a) Increase our understanding of the baseline ecology and natural variation in behavior for a deep-diving delphinid species, the long-finned pilot whale, Globicephala melas. b) Compare responses of beaked whales vs other odontocetes to playbacks of mid-frequency sonar sounds vs other anthropogenic and natural signals. c) Conduct combined visual and acoustic surveys for beaked whales and other cetaceans along with collecting oceanographic data for input into models to predict beaked whale distributions based upon characteristics of their habitats. The ultimate goals are to predict the distribution of species at risk from sonar, to define dose: response curves for risk to beaked and other whales for exposure to naval sonars, and to suggest improvements for monitoring and mitigation.