Acoustic Monitoring

Passive Acoustic Monitoring

Passive acoustic monitoring is a method to analyze the environment with as little bias from humans as possible. We use recorders to sample the environmental sounds at set times every day.

Many animals are shy when it comes to humans and change their behavior if they are aware of our presence. Our noise and size may encourage many animals to move away or hide. Sending researchers out to the field every day can also be arduous and financially consuming. Passive acoustic monitoring allows us to maximize the efficiency of data collection and still improve the overall quality of the data collected.

We can listen to common and rare animals like the Okinawa woodpecker and the reclusive Okinawa rail or Ryukyu Scops Owl. The recorders also allow us to track changes in the acoustic environment throughout the year, and even through a single day. We can detect shifts in human-caused and naturally generated sounds like diurnal cycles, morning choruses, and road traffic. We can also determine the arrivals of summer and winter migrant species, like the Ruddy Kingfisher, Black-Paradise Flycatcher, and the Pale Thrush. We can also listen to soundscape changes before and after thunderstorms and typhoons.

Our hope with this long-term passive acoustic monitoring project is to keep track of changes in the environment and the animals that live here in Okinawa for years to come. Okinawa has a rich history, and the ecosystem has changed drastically in the 100 years with the introduction of invasive animals and the loss of native animals. This delicate ecosystem is still threatened to lose more species if we don’t do our best to take care of it.