Killer Whales are found in all oceans of the world, but nowhere are they better known than in the coastal waters of British Columbia, Washington, and southeastern Alaska. Twenty-five years of study in this region have yielded many surprising discoveries about the natural history of this species. One of the most remarkable is that two genetically distinct forms of killer whales reside in these waters. These whales do not associate and each leads a completely different lifestyle: residents specialize on a diet of salmon and other fishes, while transients are hunter of seals, sea lions, porpoises, and even large whales. This book focuses on transient killer whales. Enigmatic and elusive, these mammal-hunting whales are difficult animals to study. They travel in small groups, often moving unpredictably, which makes them less conspicuous than the larger resident pods. For these and other reasons, our understanding of the life history and ecology of transient killer whales has lagged behind that of residents. Transients contains the latest information on the natural history of transient killer whales, including their feeding habits, social lives, and distribution patterns. The catalogue section contains photographs of and notes on over 200 individual whales. Numerous sidebars contain interesting observations on encounters with transients as well as information on how and where to best watch them.