Continuous monitoring of rainforest biodiversity via acoustic signal processing

There is only limited knowledge of how biodiversity changes through time, yet understanding those changes represents one of the great challenges to ecology. Knowing exactly how biodiversity is changing is important for determining which species are endangered and which are not, and for creating accurate indices that can be used to assess how effectively conservation money has been spent. There is a direct analogue with climate change: only through detailed climate data from automated monitoring stations have scientists been able to determine the rate and likely future impact of changing global climates. Exactly the same is true of biodiversity: we require detailed data from automated monitoring stations to determine the magnitude of the current extinction crisis and to best target the limited amount of money available to counteract it.

The principal explanation for our lack of knowledge is the labour costs associated with monitoring biodiversity. It is expensive to have trained scientists conducting field surveys, and the solution is to monitor biodiversity using technology rather than people. Our work will do this by automated processing of acoustic data. Sound carries substantial information about biodiversity, being used for navigation and communication by a wide range of taxa. Acoustic information can tell us a lot about which bats, grasshoppers, birds and amphibians are present in a given area. It has even been used to identify individuals, with some species such as gibbons and dolphins having calls that are distinct to every single animal in the population, much as people have distinctive voices and names.

We are going to stream data from a solar-powered sound recording system through mobile networks to an automated computer processing facility that will decipher the environmental noise to tell us which species are contributing to that noise. Our work will be take place in the rainforests of Borneo, one of the world's most biodiverse habitats and one of the most challenging natural environments in which to work. If we can successfully use technology to automatically record biodiversity here, then we can do it anywhere.

We're going to combine our research with a free public radio station to be broadcast online, providing the public with a direct line to the rainforest itself. We hope that giving people the opportunity we have had of waking up to the sound of gibbons whooping to each other and the laughing calls of rhinoceros hornbills whomping past overhead will help convince them that, although rainforests are a long way away, they are beautiful environments that can be enjoyed even from afar.

One of the likely impacts of our work is to help automate the collection of data feeding into globally important indicators of biodiversity and ecosystem health. For example, the WWF Living Planet Index relies on primary field data collected on a wide variety of species through time. The technology we are developing has the potential to generate detailed time series for many species simultaneously, and at very low cost - our estimates suggest we can reduce the annual cost of continuous monitoring by 98%, while simultaneously increasing the diversity of taxa being recorded and temporal resolution of the data being recorded. Such an automated method would also be of direct benefit to many conservation organisations. An example would be the IUCN who compile the Red List Data Books, detailing changes in the population trends of individual species as they are assigned to conservation prioritisation categories.

There is an opportunity to engage a wider public audience in this research through the development of an internet radio station. The potential audience for such a radio station is large. For example, the Royal Society for the Protection of Birds in the United Kingdom has more than one million members, and the equivalent society in the USA is the National Audubon Society with more than 600,000 members. The SAFE Project currently has a following of >110,000 people on Facebook, all of whom have some interest in the rainforest environment and may potentially engage with the radio station.

We plan to engage both the scientific and public audiences through a single website hosting an internet radio station, tentatively titled 'Hutan Radio' ('hutan' is Malay for 'forest'), playing the sounds being recorded in the rainforest . Ultimately, we would want to use such a radio station to help crowd source the identities of species, thereby gaining a significant knowledge flow from the public to researchers, but this falls beyond the scope of our Proof of Concept proposal.