Over the last twenty-five years, Norway has given priority to research to improve hunting methods for Minke whales. This has resulted in an increase in the instantaneous death rate (IDR) from about 17% in the early 1980s to about 80% today, and, thus, in a considerable decrease in the time to death (TTD) (Øen 2003). TTD data have been collected by official veterinary inspectors on board Norwegian whaling vessels and reported annually to the International Whaling Commission (IWC) since 1983. Estimates of TTD have been based, predominantly, on the ‘criteria of death in whales’ that were established at an IWC workshop in 1980 (IWC 1980). These criteria in principle require complete immobility, ie a whale can only be pronounced dead if it has stopped moving, the jaw and flippers have slackened, and it is sinking passively. However, as early as 1995 the IWC agreed (IWC 1995) that the criteria were incomplete and sometimes misleading, as they did not allow for reflex movements and seizures that occur in the unconscious state after an animal is stunned. This phenomenon is well-known from the slaughter of domestic animals (for review, see eg Knudsen 2005). The IWC identified a need for a more reliable method of determining the time of onset of permanent insensibility in whales (IWC 1995) and in particular asked for research investigating in detail the trauma, and its consequences, caused by hunting methods.