Our work is mainly on the behaviour (principally social organization and cultural transmission), ecology and population biology of sperm and northern bottlenose whales. We have ongoing research projects in the eastern Pacific (sperm whales since 1985, most recent project 2013-14 off Ecuador), and northwest Atlantic (sperm whales since 1986, bottlenose whales off Nova Scotia since 1988). We spend weeks at sea on board ocean-going sailing boats collecting acoustic, visual, photographic and oceanographic data, and then long periods analyzing them in the lab. The graduate students whom I supervise study the social organization, behaviour, acoustics, population biology and conservation of pilot, sperm and northern bottlenose whales. My own work is principally on the behaviour, social structure, population biology and conservation of sperm whales, techniques of studying social structure, and more general questions about social structure in mammals and cultural evolution.