The reach of culture into the evolutionary biology of whales

Culturebehaviour or information transmitted by social learning and shared within groupsis a system of inheritance whereby information moves from one animal to another. In common with genes, culture evolves, and as it does so can influence ecological systems and genetic evolution. My research programme strives to trace the reach of culture into the lives and evolution of whales and dolphins, a group for which culture is particularly significant.

I concentrate on the large toothed whales as their matrilineally-based and hierarchically-structured social systems promote the evolution of group-specific cultures, which are accessible for study. I lead 20-30 year-long term field studies on three species--the sperm whale, pilot whale and northern bottlenose whale--in which we collect and link individual photo-identification, acoustic, behavioural, genetic and other data.

Using the data from these field projects, we will examine the reach of culture into evolutionary biology. My primary study species is the sperm whale. Our research in the Caribbean provides individual-, dyadic-, and social-unit-level profiles of social relationships, vocalization repertoires and kinship, whereas in the Pacific we have ocean-scale data. Sperm whales communicate using codas, stereotyped patterns of clicks. Dialects of these codas characterize clans, large-scale socio-cultural entities with overlapping distributions but clan-specific behaviour. These clans are our primary avenue to whale culture.

We will plot the geographical distributions of the clans at scales ranging from the eastern Caribbean Sea to globally, assessing overlap and avoidance among clans in different oceans. Within clans, we will measure the rates of change in overall repertoire, as well as in the structure of particular coda types. Then, we will ask whether dialects are more constrained where clan overlaps are greater, indicating that the dialects function as symbolic markers of clan identity. Experimental playbacks of codas characteristic of different clans will allow us to test this hypothesis. If clans differ in their rates of dialect evolution, this indicates that higher-level cultural processes, such as conformity, vary between clans. Using a range of cultural behaviour in addition to coda dialects, we will also assess whether pairs of clans in the Pacific and Atlantic possess similar suites of characteristic behaviour, indicating parallel patterns of cultural evolution.

The proposed research is extremely original; it addresses completely novel areas of enquiry, including parallel cultural evolution, and hierarchies of cultural identity. It uses and develops innovative methodology such as dynamic social network analysis and playback technology. The significance of non-human culture to ecology and evolution is increasingly being appreciated, as is its role in considerations of management and conservation, both within Canada and internationally.