Deep in the rainforest, old phones are catching illegal loggers

Solar-powered acoustic monitoring devices are listening out for illegal loggers in the Ecuadorian forest
Getty Images / WIRED

If a tree is illegally cut down in a remote section of the rainforest, does anyone hear the sound? If that section of the rainforest is using Rainforest Connection’s treetop surveillance technology, then yes, someone actually does hear the sound. They also act on it.

The forest-monitoring technology, dubbed “Forest Guardians”, started off in 2012 as an idea to use recycled, solar-powered cellphones fitted with artificial intelligence software to monitor the activity and biodiversity of the surroundings. Re-fangled cell phones were mounted several hundred feet in the air, directly onto trees in the Supayang forest in Sumatra, Indonesia, where they listened to the sounds of the forest, connected to existing cell phone networks, and sent mobile alerts to rangers in the field when anything out of the ordinary was detected. Newer versions are now based on custom logic boards but cell phone devices are still operating in some countries, like Ecuador, where upgraded versions will be installed later this year.

The technology is developed by Rainforest Connection (RFCx). Founded in 2014 by conservation engineer and inventor Topher White, the company builds hardware and software that now protect forests in 17 countries across five continents. Inexpensive to produce yet highly effective, these rainforest “listening devices” are strategically placed in areas that are vulnerable to illegal logging and poaching.

Historically, illegal logging-prevention programs have mostly consisted of rangers walking through forests looking for obvious signs of logging. Not only are these foot patrols extremely time consuming, they’re often planned in advance so if loggers learn about the patrol schedule, they can easily work around it. Now, instead of learning about illegal logging by running into tree stumps during a weekly patrol or by viewing satellite imagery of an area that’s already been clear cut, real-time intervention allows rangers to catch perpetrators in the act.

Another challenge with foot patrols is that if a ranger doesn’t encounter illegal activity during a patrol, they may wrongly assume there is no problem in that area. Audio can disprove this assumption. By monitoring trends – say, audio devices picking up chainsaw rumbles every Tuesday morning – previous logger patterns can influence future ranger patrol routes, making them more targeted and effective. As tropical deforestation is one of the main contributors to climate change, this low-cost, highly-effective technology is reshaping the future of forest preservation and wildlife conservation around the world.

About 100 kilometers from Ecuador’s metropolitan capital, Quito, sits Mashpi Lodge, a high-end cloud forest hotel serving as a weekend escape for well-off Quiteños and international travelers. Though the resort is best known for its eco luxury status (it was named by National Geographic as one of the most unique lodges in the world), the lodge is also unique in that it was established to protect a heavily logged stretch of forest. Profits from the lodge are funneled into preservation initiatives, like the site’s resident biology program, research lab, and the continued expansion of protected land.

Through Mashpi Lodge’s associated foundation, Fundación Futuro, the reserve recently doubled its size by acquiring an additional 1,300 hectares of forest and they plan to purchase an additional 80 hectares this year. According to the foundation’s Executive Director, Carolina Proaño-Castro, they’re about halfway to their goal of controlling and protecting 5,000 acres, not necessarily by buying all of it, but by “working with the landowners on conserving, restoring, and transitioning to sustainable use.”

Though the reserve seems to be in the middle of nowhere, it’s close enough to small towns that cell phones still have signal in the forest, which made it a good candidate for RFCx’s technology. In 2019, the lodge reached out to RFCx, who visited the reserve and installed nine treetop listening devices. According to Felipe Andrade, a biotechnology engineer and the Carbon and Biodiversity Management Coordinator for Fundación Futuro, some illegal activities stopped as soon as the devices were installed – not because the devices alerted rangers to illegal activity, but because their mere presence was enough of a deterrent. “All of the communities around the reserve knew we began monitoring so they stopped any activities in the area.”

The initial idea for the Forest Guardians program was based on the assumption that if you can identify illegal logging, you can stop it. White, the founder of RFCx, says that over time, however, he’s learned that awareness isn’t always sufficient. In many cases, the mere presence of surveillance technology won’t be enough to halt illegal logging: when the devices do pick up sounds of illegal activity, there needs to be a support system on the ground to intervene. According to White, “you don’t just need people on the ground with tech support, you also need collaborative support.”

In many countries, rules are in place to protect forests but those charged with that protection have difficulty identifying and catching perpetrators. White believes that conversations are more helpful than graphs, and that Mashpi Lodge was the perfect partner not only because they were heavily invested in conservation, but also because they had strong relationships with the communities surrounding the lodge, and they employed forest rangers that lived in these communities (some of whom are former loggers).

And, crucially, this kind of technology is about more than just stopping crime – it is also about getting to know the rainforest better. Tools such as satellite imagery allow us to monitor fairly easily how the forest cover is changing on a large scale, but while we are able to glean information about what's happening to rainforests, it is much harder to understand what's happening to the animals living within them. That is why, RFCx devices – initially set to listen specifically for sounds like chainsaws, have since evolved to be able to identify gunshots, people’s voices, and animal sounds. The same acoustic sensors and analytical platforms that register and record chainsaw noises have now become real-time biodiversity monitors.

RFCx technology has been used to automate the species-identification of hundreds of frogs, birds, and mammals and it has simplified the process that would allow the addition of hundreds more species into its own database. For biologists at Mashpi, it means that instead of having dozens of species experts spend months sifting through thousands of hours of audio, the technology will process three months of audio in mere minutes.

Each species has its own unique set of features or “sound signature” (tone, volume, pitch, length of call, etc.) that is used to create a species algorithm. This sound signature can then be cross-checked against an existing data set to confirm the presence of an animal in a given area. For example, a Mashpi biologist can input a species algorithm (say, a recording of a particular parrot species from elsewhere in the region) into the RFCx data set. The program will then generate examples from the existing audio data – similar bird sounds recorded in the Mashpi reserve – that the system believes match the inputted algorithm. Once the system has identified the most likely positive matches, the potential matches are then presented to a human expert to confirm whether or not the sound is, in fact, the particular parrot species in question– a process which, in turn, helps refine the AI system to become more accurate.

Last fall, by inputting the species algorithms recorded at Mashpi into the RFCx system (which already contained recordings from species from around the world), the system identified 40 species present in the reserve. RFCx and Fundación Futuro are currently working on building AI models for those species; this year, they plan to develop algorithmic sound signatures for up to ten more species.

RFCx believes that anyone studying bioacoustics anywhere in the world could use this system. While the technology is specifically designed to support researchers and scientists, the user interface is continuously improved to make it more user-friendly for the community residents doing the actual on-the-ground data collection and interventions to stop illegal logging. “The only people that can fix things are the local people who are committed to the area,” White says. These local “heroes”, according to White, are not just part of the solution – they are the solution. They just need the right tools to support their fight.


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This article was originally published by WIRED UK