Bioacoustic monitoring could strengthen corporate zero deforestation commitments

Our eyes in the sky have revolutionized forest monitoring, giving us a big picture of the state and health of the planet’s green spaces. But while satellites measure tree cover, most do not capture what happens under the canopy, such as poaching, incursions from invasive species, degradation from selective logging, and understory fires.

These gaps can be filled instead with ears on the ground.

By capturing an entire soundscape using simple recording devices, bioacoustic systems can document a wide range of species and detect very minor changes in ecological communities, even potentially revealing when humans are present in a forest.

These activities have a significant impact on wildlife populations and forest health, as well as providing warning signs about impending deforestation. For example, tiger poachers operating in a dry peatland represent a fire risk: All it takes to ignite a haze-causing inferno is a dropped cigarette.

Camera traps get us closer to a solution, but they do not tell the whole story since they capture just a fraction of activity. They are often conspicuous and can be destroyed by those who want to avoid detection.

But acoustic recorders these days can detect animal calls and song from several hundred meters away. Autonomous sound-recording devices come as small units that are inconspicuous, can be programmed to record either continuously, if there is sufficient solar power or cellular network signal for direct transmission of data to cloud storage, or at given intervals, if battery power and data storage are limited.

They can also be useful for realtime interdiction – the San Francisco-based non-governmental organization Rainforest Connection has proven that a bioacoustic system linked to a mobile phone network can detect gunshots, chainsaws, and the sound of motorbikes and truck engines. Devices can be mounted out-of-sight in the canopy, so they are not obvious to passers-by below.

Given this functionality, bioacoustic systems can be used for many conservation projects, including corporate zero deforestation commitments, which could offer a good opportunity for pilot schemes, and eventually even a financing mechanism for implementation.

Forty governments, 20 sub-national governments and 57 multinational companies have pledged under the New York Declaration on Forests to halve deforestation by 2020, while scores of plantation companies in Singapore, Malaysia and Indonesia have committed to eliminate deforestation from their supply chains.

But in the past year, investigations have revealed that some companies continue to source palm oil and wood produced via ongoing conversion of peatlands and forests in Indonesia. Thus there is renewed skepticism about these corporate commitments at a time when concerns about climate change and biodiversity loss are growing. One way to address this lack of trust would be for companies to increase accountability within their supply chains.

Indeed, this is already happening: Food and beverage giant Nestle is using high-resolution satellites to monitor suppliers, while agribusiness group Wilmar is mapping its suppliers and reporting on the results via an online dashboard. But gaps remain.

Companies have an interest in maintaining the forest reserves they have committed to protect. Therefore, they would benefit from having real-time alerts on the status of these conservation areas. At the same time, there are marketing benefits of demonstrating a robust monitoring system to customers, regulators and suppliers. There is even a possibility that a firm might use a bioacoustic system to showcase what species its commitments are helping protect. In cases where habitat restoration is involved, companies can establish baselines to document the recovery of species, definitely proving the ecosystem is healthy and functioning.

But the really exciting aspect of networked bioacoustic systems comes from making audio data available to scientists. The beauty of bioacoustic data is that researchers can run algorithms to map soundscapes, allowing us to better understand ecological communities and monitor change over time, including the impacts of drought, storms and seasonality. And as algorithms improve, they can be re-run against a constantly growing library of bioacoustic data, providing more insight.

This could result in a scenario where zero deforestation firms are funding real-time monitoring of forests, with data fed into the cloud for use by scientists, offering a better picture of what’s working and what’s not working in conservation and landscape restoration. Combined with satellite data and networked camera traps, we would have a much clearer picture for measuring trends in wildlife populations, detecting threats to forests before outright deforestation occurs, and understanding the earnestness of corporate conservation commitments.

Note: this piece was published as a perspective in The Straits Times on January 5, 2019. The paper upon which this is based was published in Science on January 4, 2019 with Zuzana Burivalova and Eddie Game as co-authors.