A new San Francisco tech start up called Rainforest Connection is using discarded smartphones and the help of indigenous Brazilians to stop illicit logging. Discarded smartphones are transformed into solar powered listening devices that can recognize the sounds of chainsaws and trucks and send alerts to rangers and officials.

According to a two-year investigation by Greenpeace, illicit logging is “out of control” and that 78% of logging is illicit in Para State, Brazil’s largest producer and exporter of timber. This illicit logging not only effects local flora and fauna, it also threatens indigenous peoples’ lands and is a major contributor to climate change.

The main advantage of Rainforest Connection is that, unlike standard satellite imaging systems, it can transmit real time information directly to those who responsible for stopping illicit logging. The start-up has recently partnered with the Tembé tribe, training 30 members as forest rangers to stop illicit logging in their land.

Vasco M. van Roosmalen, who is running the training program, says that this new start-up is especially promising for combining technology with, “the on-the-ground presence and determination of local indigenous groups serving as guardians of their traditional lands.” This combination of real time monitoring and local vigilance will hopefully be an effective combination in stopping rampant illicit logging.