Sussex researchers record soundscapes for BBC's Springwatch
When it comes to monitoring wildlife, what you can hear is just as important as what you can see.
Two University of Sussex academics are combining their very different disciplines to analyse soundscapes of our natural world in order to pick up changes not apparent to the human eye.
This evening (15 June) conservation biologist Dr Mika Peck and musician/ programmer Dr Alice Eldridge will be on BBC Two’s Springwatch showing how they have set up recording equipment in varied habitats – a woodland, a meadow and a river - to capture data that will be analysed by computer algorithms and by the human ear.
The BBC project at Sherborne Estate in Gloucestershire is a small-scale version of the work Mika and Alice have been doing for the past few years in the rainforests of Ecuador and locations in Sussex.
Mika says: “We’re interested in what is called the acoustic niche hypothesis. This is the idea that in a stable, natural environment the soundscape is neatly partitioned so that each species of animal has its own bandwidth and then can use sound to protect its space or find a mate.”
Alice, a trained cellist and computer scientist says: “We can think of it in musical ways. In an ancient stable ecosystem you hear lots of voices, but they take turns and complement each other, like the instruments in a symphony. In an environment that’s been disturbed with invasive species, the soundscape becomes messy - like a load of drunk people talking across each other.”
For several years Mika’s work in Ecuador has involved developing projects to protect the critically endangered brown-headed spider monkey, whose habitat is being destroyed through logging. Although he has used drones and satellites to create visual data for his research, it's been difficult to see what’s going on below the rainforest canopy. “It could be a silent forest through over hunting,” he says. “It could be a forest that’s degrading and you wouldn’t even notice.”
By placing sound recording devices at regular intervals throughout the protected area for the spider monkeys, he and Alice will be able to discover not just what’s happening in terms of the biodiversity of the area, but also whether illegal hunting and logging practices are continuing.
Mika says: “The great thing is that we’re not disturbing the environment, and these technologies also can provide us with the ability to monitor shotguns and chainsaws.”
The hundreds of thousands of audio files they have collected from Ecuador – and from the sites in Sussex (an ancient woodland near Lewes, a barley field near the University’s campus, and the Knepp Castle rewilding estate near Horsham) are now in the process of being analysed.
Alice says: “We’re looking at the whole soundscape – so we’re not asking whether it is a flute or a violin (or in the case of biodiversity to identify individual species), but how much sound there is and how it is distributed.
“We are exploring two different approaches. One is very intense computationally but could give us a whole new way of listening. The other tries to find very simple methods that we could use, for example, on upcycled smart phones in the forest. So there is some ‘pure’ research, and also very practical tools to solve very real issues in conservation today.”
While Sussex has long championed interdisciplinary research, it was a chance conversation in The Bridge Café on the Sussex campus that led Alice and Mika to begin the project.
Old friends from many years ago, when Mika taught Alice the Brazilian martial art capoeira, Sussex alumna Alice had recently returned to Sussex to run the Music Informatics course in the school of Engineering and Informatics.
“I became interested in the acoustic niche hypothesis from an evolutionary perspective whilst studying Evolutionary and Adaptive Systems MSc at Sussex," says Alice, who is now a research fellow in the Sussex Humanities lab. "It made us think about sound as a resource, just like food or habitat.
“I was thinking about this as an art project to raise awareness of soundscape conservation when I bumped into Mika, who instantly saw a practical application. This is a really nice example of collaborative research. I’ve always been interested in the interactions between arts, biology and technology.I don’t think either of us would have carried out this research individually.”
For Mika, the collaboration has given his conservation project a real boost.Through his research grants, he has been able to train and support local people in Ecuador to become parabiologists.They will also be able to listen to the recordings and corroborate what they can hear with what the computer algorithms produce.
“Although we are largely visual primates, the human brain is very good at recognising sound,” he points out. “We aren’t trying to model human listening, but to see if there are simple ways to summarise the audio recordings which give information about the health of the habitats. So it’s important that we have people listening to the sound files so that we can establish the correlation.”
Viewers of Springwatch will be invited to listen to sound files recorded at Sherbourne Estate in Gloucestershire, where the series is based this year. “This is the amazing thing with gathering data like this,” says Mika. “It’s the sort of citizen science that we can all take part in.”