Bioacoustics is the scientific study of biological sounds. The International Bioacoustics Society (IBAC), which has a long history dating back to 1969, was having a congress every other year before the covid-19 pandemic attacked the world and prevented people from travelling. The latest IBAC congress had been originally scheduled in 2021, but had to be postponed twice. The long-waited congress finally took place in October 2023, for the first time in East Asia in its history. In the conference hall of Hokkaido University located in Sapporo Japan, over 200 bioacousticians from over 20 countries gathered and enjoyed the intense discussion on raging topics, including mechanisms of animal vocalizations, acoustic monitoring of environment, and evolution of acoustic communication.
Masayo Soma, IBAC organizer / IBAC executive committee member.
Hana Goto PhD candidate at Hokkaido University, Japan.
Can you tell us a bit about yourself and your research interests?
I am a postgraduate student at Hokkaido University where I will start a PhD next April. I have been fascinated by nature since my childhood and I am curious why animals behave the way they do. In addition to making new discoveries about animal behaviour, I would also like to communicate biology facts to the public and share my fascination with nature.
I am particularly interested in acoustic communication, especially in birds. Birdsong is not only fascinating in itself, but is also an interesting subject for research. Birds use acoustic signals to communicate in habitats that are sometimes very noisy – for instance early in the morning in forests where many other birds are singing at the same time, in meadows with strong winds, and also in cities where many cars pass by. I would like to know how birds manage to make themselves heard in their noisy, sound-filled worlds and to whom they are actually talking to.
What first interested you in this field of research?
I remember when I was 10 years old, I was very surprised to hear a jay imitating the calls of other birds. At first I thought it was an odd tit, but when I searched for the bird, I discovered it was actually a jay! Since then, I have been interested in the sounds of animals and I dreamt of becoming a researcher in acoustic communication.
During my undergraduate studies I continued to develop my interest in bioacoustics through books, but the most significant turning point came in my fourth year when my mentor Professor Soma told me about a Master course in Bioacoustics in France and encouraged me to enroll. I still vividly remember seeing the schedule of this course and feeling a rush of blood through my body. Completing a master’s degree in my favourite field was a big step ahead for me and I’m very grateful to Professor Soma that she gently pushed me to leave the comfort zone of my home university to pursue my goals.
Can you briefly explain the research you presented at IBAC 2023?
I have looked at whether canaries avoid singing during loud noises. Noise disrupts acoustic communication and many bird species are known to adjust their signal timing to avoid the masking of their signals. I initially expected that domestic canaries would also adjust their song timing to avoid overlap with noise, especially when the noise is very loud. To test this idea, I ran a series of experiments in which I recorded singing birds in sound-shielded chambers while I played back bursts of white noise with different amplitudes to them. The results were very surprising – the noise actually triggered singing in the tested birds. And it did so irrespective of the noise amplitude. This is somewhat paradoxical because it leads to the most unfavourable signal-to-noise ratios. There are a number of possibilities as to why canaries preferred to sing in noise, including the noisy nature of their habitat, the effects of domestication and to avoid predators. However, the question why the birds show this peculiar behaviour cannot be answered from my experiments. Anyhow, the finding that noise elicited bird song led us to propose a broader concept of noise that includes both inhibitory and stimulatory effects.
How will you continue to build on this research?
It would be interesting to find out which frequency bands are associated with song promotion and whether this phenomenon can also be observed in other species that live in less noisy habitats. For my PhD project, however, I will focus not on the timing but the amplitude of bird song. The canary, which I studied for my Master’s thesis, has a relatively loud song. On the other hand, I have also noticed that there are birds whose voices are so quiet that you have to get very close to hear them. I plan to focus my research on these differences in song amplitude and how they are related to individual and species-specific traits.
James Rule Postdoctoral researcher at the Natural History Museum, UK.
Can you tell us a bit about yourself and your research interests?
I am an evolutionary biologist/palaeontologist, interested in mammalian evolution with a focus on pinnipeds (true seals, sea lions, fur seals, walruses). My current project is investigating the evolution of the hearing of pinnipeds..
Can you briefly explain the research you presented at IBAC 2023?
Seals have the remarkable ability to hear amphibiously (both above and below water). My presentation at IBAC involved CT scanning the ear regions of modern and extinct seals, and using morphometric and macroevolutionary methods to analyse how their ears evolved throughout their evolution.
You’ve won a PeerJ Award before – is the work you presented a continuation of that research or are you working on something new?
This work is a continuation of the same research from my previous PeerJ Award, and has greatly expanded in scope since my first presentation.
How will you continue to build on this research?
I am now focusing on finishing up processing and analysing the data for this project.