Cultural Transmission of Humpback Whale Song
Research on humpback whale song as a cultural phenomenon is currently being investigated by Jenny Allen for her PhD, which began in 2013. She is examining the fine-scale cultural transmission of the song in East Australia and the neighboring population of New Caledonia. This is a continuation of work previously conducted by Dr. Ellen Garland for her PhD work, which she completed in 2011. Ellen's research investigated the cultural transmission of humpback whale song and metapopulation structure in the South Pacific Ocean.
Male humpback whales produce long, complex 'songs' that are thought to function in mating. All males within a population sing the same song but the song changes rapidly over time. All males must incorporate these changes to maintain song similarity. Males are believed to learn the song each year from their peers through cultural transmission, a type of social learning.
As well as moving between individuals in one population (e.g. the east Australian population) the songs also move between populations. The best documented example of this is songs moving from west to east across the South Pacific, from east Australia through New Caledonia, Tonga, Samoa, the Cook Islands and French Polynesia, over periods of up to four or five years. This is possibly the most geographically expansive and rapid example of cultural transmission in the animal world.
Fine-scale song exchange in two neighbouring populations of humpback whales
This study focuses on songs sung in the east Australia and neighboring New Caledonia populations to see if there are any predictable or consistent patterns in the evolutionary changes that happen from year to year. Autonomous underwater acoustic recorders are in place during the whale migration season in 2014 and 2015 off the Sunshine Coast of Queensland and the southern coast of Ile Quen in New Caledonia. Archival data from both populations will also be used in conjunction with the current data to compare how songs have changed over the past decade.
By taking a closer look at how the song changes, we can learn more about way in which whales within a population learn the song, the type of information that might be contained within different parts of the song, and potential functions of the song. Humpback whale song is also an excellent example of cultural learning in a non-primate species. A better understanding of this could shed some light on the cultural learning processes of our own behaviours. (Project leaders: Jenny Allen and Michael Noad)
Data and field work in New Caledonia is being done in collaboration with Dr. Claire Garrigue from Opération Cétacés.
The use of songs by humpback whales across the western South Pacific region
This project investigated the change and subsequent transmission of humpback whale song throughout the South Pacific region over the last decade.
Populations within an ocean basin have similar songs with this similarity dependent on geographical distance between populations. The main populations being investigated in the region are eastern Australia, New Caledonia, Tonga, American Samoa, the Cook Islands and French Polynesia. Previous studies have demonstrated similarities among the songs of the South Pacific populations and eastern Australia for a particular year, or from one population over time, but none examined the dynamic nature of song change within the region.
Results show songs are horizontally culturally transmitted from eastern Australia in the west across the region to French Polynesia in the east. Quantifying how and where song changes are happening and tracking their subsequent spread will hopefully produce a better understanding of population structure in the region. This project was undertaken in collaboration with the South Pacific Whale Research Consortium. (Project leaders: Ellen Garland and Michael Noad).