The cultural borders of sperm whale society

Hal Whitehead uses a 40' ocean-going sailing boat to study the deep-diving whales of offshore waters, the sperm and northern bottlenose.   His research focuses on the behavior, social organization and transmission of culture among these animals, as well as on their ecology, population biology, and conservation.  Principal research tools are photoidentification, acoustic tracking, and genetic analysis.  He also works on general methods of analyzing animal societies and cultural evolution, in theory and practice.  Hal is a University Research Professor at Dalhousie University, in Halifax, Nova Scotia.

The sperm whale is the dominant mammalian predator of the deep ocean, and has been a principal target of two massive hunts.  To understand the nature of this extraordinary animal, its role in the marine ecosystem, and the effects of whaling on the populations we need to know how sperm whales use their habitat.  What are the borders of sperm whale society?  The International Whaling Commission’s attempts to delineate “stocks” had no validity; there seem to be few lines in the ocean that sperm whales do not cross.  A more fruitful approach is to relate sperm whale distributions and movements to oceanographic features.  However, at least in the South Pacific, it seems social attributes delineate distinct sperm whale populations more than geographic or oceanographic features.  The females belong to clans which overlap in their distribution but are distinctive in their vocal dialects, movement strategies, feeding success and reproductive rates.  As there are few genetic differences between clans, the differences between them are cultural.  These clans have large numbers of members, and stretch over many thousands of kilometers of ocean.  Culture thus seems to be the primary feature in defining the borders of sperm whale society.  Our results suggest that the clans may have been differentially affected by whaling, and will respond differently to global climate change.