Marine Science, University of St Andrews
Tenure since 2017
The Cultural transmission of humpback whale (Megaptera novaeangliae) song in the central and eastern South Pacific Ocean
Some of the strongest evidence for nonhuman culture is found in the complex songs of humpback whales (Megaptera novaeangliae). Culture can be defined as the “behavioural variation between sets of animals maintained and transmitted by social learning” (Laland & Hoppitt, 2003). Male humpback whales produce a vocal sexual display called ‘song’ during the breeding season. Song is a long, stereotyped acoustic signal with a hierarchical structure, such that each song is composed of a set of themes, each theme is composed of phrases and each phrase is composed of a stereotyped sequence of units. All male humpback whales of each breeding population sing the same song at any given time. Each song changes gradually with all singers of the same population updating their song to maintain similarity across the population.
While humpback whales can be found in all of the world’s oceans, the transmission of song in the South Pacific Ocean is of particular interest to researchers due to the occurrence of song ‘revolutions’ in which a population discards a current song in
favour of a new, and completely different song type. This pattern of transmission, which doesn’t occur elsewhere, may be due to migration patterns. Song types have been found to radiate eastward across the South Pacific breeding areas, as individuals within an adjacent population repeatedly adopt the neighbouring population’s song. For example, the song of Eastern Australia was transmitted eastward all the way to French Polynesia in only two years. It is not yet known how this song transmission is achieved. It is possible that individuals from different breeding locations come into acoustic contact through shared feeding grounds or shared migration routes. Alternatively, individuals may visit different breeding grounds within a breeding season or individuals may move between breeding grounds. It is therefore important to study in detail how song is transmitted between breeding locations to understand the factors underpinning the phenomenon of song revolutions. This research may also aid understanding in the utility of song as an indicator of population structure, which could be useful in protecting the diversity of the South Pacific population.
My PhD research will help to elucidate how a complex sexual display, song, of the humpback whale is transmitted between breeding subpopulations of the South Pacific Ocean. More specifically, my PhD research will address two key areas: firstly, how the Cook Islands function in the transmission of song to neighbouring populations and secondly, how song is transmitted as we move further eastward, past French Polynesia, towards Ecuador. I will address these research gaps by analysing and comparing long term datasets of songs recorded in the Cook Islands, French Polynesia and Ecuador.
Natalie graduated first in her class from the University of Glasgow with a first class integrated Masters with honours degree in Marine & Freshwater Biology. Natalie was the highest ranked student in the third (2014) and the fourth year (2015) of her degree and was then awarded the Graham Kerr Memorial Award for Excellence in 2016. She was accepted onto the competitive masters in science programme through which she worked for one year in industry at Scottish Natural Heritage (SNH). At SNH she gained experience working in conservation policy while leading a commissioned research project.
During her summer breaks at university, Natalie attained additional research experience. This has included working as a research assistant, gaining a Carnegie Vacation Scholarship to perform research in bioacoustics and also securing a Reed Eselvier New Scientist Scholarship to complete an internship in cetacean research. This additional work has surmounted as experience and skills in a diverse range of research methodologies from respirometry to acoustic analysis, genetic analysis and camera monitoring.
Natalie’s Carnegie Vacation research project used passive acoustic monitoring to detect individual variation in water rail (Rallus aquaticus), her honours project explored haul-out physiology in moulting harbor seals (Phoca vitulina) and her master’s project used remote time-lapse photography to monitor attendance of guillemots (Uria aalge) outside the breeding season at two colonies in the Northern Isles of Scotland.