Costa Rica Saves Forest Ecosystems By Listening To Them
Monica retamosa heard the bellbird for her first time while changing batteries on a tape recorder. She stood on the forest floor and scanned the trees for its source, looking for its metallic, powerful sound. For half an hour, she searched for it without success. Retamosa smiled: She cares for ecosystems in Costa Rica’s AmistOsa Biological Corridor by listening to them. Retamosa still smiled. She listens to ecosystems in Costa Rica’s AmistOsa Biological Corridor. They use sounds to communicate their identities, alert others of danger, guide them, or aid in hunting and defense. Researchers have been tracking species for decades with recorders, and they still do. However, remote recording devices are becoming more popular. Bioacoustics is the study of sounds made by organisms. Retamosa’s work has lasted for 10 years. When bioacoustics combined with sounds made by humans and natural sounds, like the crashing waves of the sea, it is possible to interpret a deeper ecological meaning. Ecoacoustics is a wider analysis of sound. This work in Costa Rica is based on this. This wider analysis of sound is known as ecoacoustics–and it is exactly the work underway here in Costa Rica.A three-wattled bellbird (Procnias tricarunculatus) in Costa Rica.
Photograph: Juan Carlos Vindas/Getty Images
Retamosa has been working for 20 years at the National University of Costa Rica, at the International Institute for Conservation and Wildlife Management. She uses bioacoustics and ecoacoustics to investigate the sounds of this small Central American country that hosts more than half a million species.
“Sounds have been forgotten from a conservation point of view,” Retamosa says. Most of the time we hear more than see. The sound or lack of it is likely to be the first thing we notice when there’s a disturbance in a system. Researchers can now hang sensors to record short snippets from the day without disturbing wildlife. Retamosa likes this strategy because it’s non-invasive to animals, makes it easier to have ears in large areas and hard-to-reach places, and occasionally helps discover mysterious species.
Although she prefers to monitor ecosystems from a distance, Retamosa still has to go deep into the forest to set up recorders. The field is fascinating but not a place to take a Sunday stroll. Along with Jimmy Barrantes, and Randall Jimenez, she has walked miles in mud and through branches. The three have climbed and slid down endless hills. She fell once and broke her ribs. The work is not done after the installation. They have to return to replace the batteries and memory cards. Other countries use solar panels to get real-time information, but in Costa Rica’s dark and humid rainforests, it is still done manually.
