Warren Horrod-Wilson

2022 PhD Studentship
The evolution of vocal learning
Exploring the evolution of vocal learning through comparative cultural evolution
Royal Holloway, University of London

Language and the cultural diversity associated with it is central to human life. How vocal learning evolves, however, is poorly understood.

Bird song provides an ideal system to explore vocal learning behaviour due to the diversity of species, the communal nature of many birds and their rich vocal repertoire. Until recently, however, we lacked the tools to quantify this behaviour at scale in closely related species.

Recent work by Rob Lachlan from Royal Holloway, University of London, has led to the development of new tools and techniques to compare vocal learning between species and examine the evolution of these traits.

For the first time, we can begin to examine why some species have developed stable vocal cultures whilst others have not. What variables determine whether individuals will learn their song, as opposed to rely on innate biological mechanisms? When is an individual more susceptible to learn socially, rather than to through trial and error? And which birds are most likely to be selected as tutors by learning juveniles, what factors determine their suitability?

Answering fundamental questions like these can help us understand major evolutionary processes and transitions linked to the biology of vocal learning, human language, and cultural evolution.

A male common Reed Bunting, Emberiza schoeniclus, one of the 45 species belonging to the Emberizidae family and a target species for this research. Photo: Wikipedia
Collecting song recordings at an unprecedented scale

Previous research has typically used a single species to make inferences about song learning ability in birds.

In contrast, I analyse multiple species of buntings in the Emberizidae family, alongside computer simulations. This has the potential to provide the first detailed analysis of the conditions under which vocal culture develops.

A second part of my research investigates cultural evolution in garden bird species at a national scale. In partnership with the British Trust for Ornithology, we plan to collect song recordings using a citizen science programme that will involve birdwatchers and the general public across the UK.

Example of the Reed Bunting species song in the form of a spectrogram, which is a graphical representation of the frequencies of a sound signal as they vary with time. On the x-axis is time, and on the y-axis is the frequency of sound (measured in hertz), where a higher frequency corresponds to a sound that is higher in pitch. Note the distinct elements that make up the song. These elements differ between populations of birds, forming what are referred to as dialects. This can be understood as a form of vocal culture in birds. Photo: Xeno-canto, where you can also listen to the song.
Evolutionary way of thinking

Biological organisms are governed by a clear set of rules that determines how they change, or evolve, over generations of time. The depth and breadth of these biological rules, like natural or sexual selection, will never cease to fascinate me. Evolution has led to the emergence of a seemingly infinite diversity of biological organisms that have arisen in response to their own unique natural history.

The theoretical foundations of evolutionary biology, and how they can be used to understand the causal factors that underpin the characteristics of other species, and our own, has played a huge role in shaping who I am as a person. It informs both the way I think and solve the problems that I face in my day-to-day work and my own personal life.

Upon completion of my PhD, I aim to continue with a postdoc to build my repertoire of scientific research methodologies and secure a position as a university lecturer.

I want to encourage more people to learn about evolution and how to manage problems they care about using an evolutionary way of thinking.

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Researcher profile