La Selva Biological Field Station, Costa Rica — Dr. Scott Brandes, a postdoctoral researcher with the TEAM Initiative, Dr. Piotr Naskrecki of the Invertebrate Diversity Initiative (IDIIDI) and Dan Schollaert, a volunteer for TEAM, began the initial testing of acoustic monitoring hardware. The team of three field-tested the hardware during the first three weeks in August, 2003 at the La Selva Biological Field Station in the Caribbean Lowlands of Costa Rica.

As Brandes reports, "We began field testing our autonomous sound recorders this August at the TEAM site in Costa Rica. These weather-proof devices use a personal digital assistant (PDAPDA) to record sound at scheduled intervals of time, they have enough storage capacity to record 190 minutes of high quality sound (16-bit at 44.1 kHzkHz), and have a battery life of about a month. We plan to use them to record sound for 10 minutes each evening just after sunset, when nocturnal katydids are particularly vocal. Initial results look good for the recorder, but the waterproof microphone cover is attenuating sound a little more than we would like, so we have more work to do in designing a better microphone housing."

Once the devices are ready for full deployment, Brandes and Naskrecki will use them to record nocturnal insects, primarily katydids and crickets. They hope to follow with additional recording units to target frogs and birds. These audio devices are only used to record sounds at specified times. Brandes and the TEAM Initiative rely on audio post-processing to identify any of the target species that might be calling. In this TEAM hopes to establish long-term trends in a variety of acoustically active taxa. Terrestrial animals communicate acoustically all over the planet. Nowhere is this more apparent than in the tropics, where species-richness is several times greater than in higher latitudes. A large percentage of birds, frogs, bats and insects create sounds that are often species-specific. This abundance of sound provides a ready-made source of information that can be used to explore the composition of this diversity in particular regions of interest.

For more information, contact Scott Brandes at s.brandes@conservation.org