Eavesdropping on seabirds

Aline Da Silva Cerqueira

Discover how you can listen to gannets and help marine biologist Aline da Silva Cerqueira with her important research...

Seabirds are remarkable creatures. They can fly long distances at sea and spend most of their lives out of sight of land. Some species can swim and dive with the same dexterity that others can fly without even flapping their wings. They are masters of the oceans and the winds, just like they are masters of the land at their vast breeding colonies. They have adapted to all climates and almost all environments around the world.  

However, they are one of most threatened groups of animals in the world. Their capabilities to withstand the pressures imposed by a fast-rising human population and human resource consumption are limited and could drive many species to extinction during the next few years. Threats to seabird life are found both on land and at sea, though the overlap between foraging areas and fisheries represents the most widespread and immediate threat to many marine bird species around the world. Hundreds of thousands of seabirds are killed each year as bycatch in fishing gear.  

Infographic showing threats to seabirds

Understanding how, where and when seabirds are exposed to hazards is crucial to identifying mitigating measures and conservation efforts. My PhD research investigates seabird behaviour during foraging, using a combination of bird-borne GPS trackers and sound recorders. I ‘eavesdrop’ on seabirds to find out what they are up to at sea, while trying to also detect the presence of other animals and fishing vessels. This makes it possible to pinpoint specific areas at sea where animals congregate and/or interact with fisheries. 

The sounds seabirds make provide acoustic cues to everything these animals do. As they vocalise, move, feed and socialise they produce sounds that reflect the types of activities they engage with in their environment. Likewise, environmental sounds, namely nonbiological natural sounds (geophony) and the sounds produced by other organisms (biophony) and humans (anthropophony), create a diverse soundscape that helps build the context in which animals exist. 

Together, these sounds provide an insight into the ecology, behaviour and physiology of wildlife and comprise a valuable set of information for biodiversity and ecological research. The soundscapes of seabirds are therefore a repository of information waiting to be explored, with the potential to unveil new insights into seabird social behaviour and interactions with their environment.  

Gannets on Grassholm Island

To obtain one of my seabird acoustic datasets, I travelled to Grassholm Island, off the Pembrokeshire coast in Wales, to embark on my first fieldwork expedition in the summer of 2019 and joined an amazing team of seabird researchers led by Professor Steve Votier. Steve has been researching the population of Northern Gannets (Morus bassanus) at Grassholm, the third largest in Britain, since 2006. Together with his team, we deployed sound recorders and GPS trackers directly onto gannet individuals to explore their marine soundscapes.  

We successfully collected sounds from 10 gannets using AudioMoth acoustic loggers made by Open Acoustic Devices. In total, over 600 hours of seabird sounds were recorded, across all recorders, corresponding to 55GB of data, which must be analysed. 

Two scientists fit an acoustic logger onto a gannet

Having recently analysed the marine soundscapes of two species of albatross at Bird Island, South Georgia, manually classifying over 650 hours of albatross sounds, I had become aware that eavesdropping on seabirds (and extracting useful information from it) is a very labour-intensive and time-consuming process (albeit very interesting)! So, to speed up the sound analysis process of the gannet recordings, and to create opportunities for public participation in seabird ecology research, I created a citizen-science project called Seabird Soundscapes hosted by the online platform Zooniverse.  

The Seabird Soundscapes project is powered by volunteer citizen-scientists (like you!) who can help classify seabird sounds through simple online tasks. Each task consists of participants listening to and visually inspecting spectrograms of 10-second excerpts from the original audio files that were recorded during the Grassholm expedition. Citizen-scientists can then classify each sound they listen to by choosing from the sound category options in the Seabird Soundscapes ‘Classify’ task. All sound classifications are then stored and used to create a library of seabird sounds. 

Take part in the Seabird Soundscapes project 

In the next stage of this study, I will be using this library to create an automated seabird sounds classifier based on parameters learnt from the classified data. These steps will enable faster analysis of the seabird acoustic dataset and at the same time allow the public to delve into Welsh marine soundscapes from a bird’s ear perspective. This is a unique experience that I am very happy and excited to share with many seabirders and citizen-science enthusiasts.  

The Seabird Soundscapes project logo, a gannet and blue background.
Once the Grassholm audio data are fully classified, I will be able to link the sounds to the GPS data to determine the spatial distribution of sounds along each foraging track. This step is important because it will allow me to identify specific locations where birds congregate at sea and understand how individuals interact and react to other individuals and their surroundings across broader scales of space and time. 

Eavesdropping on seabirds or, technically speaking, acoustic tracking of seabirds, is a promising way to learn about these animals in the wild. Seabird soundscapes remain underexplored outside of nesting sites, highlighting the importance and the potential of at-sea acoustic surveying to fill in the knowledge gaps about seabird ecology and behaviour at sea. We hope the Seabird Soundscapes project will help refine our knowledge about seabird social interactions and communication during foraging.  


Follow Seabird Soundscapes on Twitter at @SeabirdSounds and join the project’s Facebook page.  

The Seabird Soundscapes project is the result of a collective effort, involving Aline da Silva Cerqueira, Professor Terry Dawson from King’s College London, Dr Robin Freeman from the ZSL Institute of Zoology, research collaborators Professor Steve Votier & his team, the Zooniverse crew and the amazing citizen-scientists that voluntarily dedicate their time to help us classify gigabytes of acoustic data and without whom this study would not be able to achieve its objectives.  

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