Ecoacoustics – animal research in the Amazon

Ecoacoustics will be applied to the world’s largest rainforest area, known as the “Green Lungs of the Earth.” The Amazon, represents one of the most fascinating and unusual ecosystems on the planet. Among the dense lianas, lush vegetation and mystical beauty is home to more than 3 million species of animals and more than 2,500 species of trees, accounting for one-third of all tropical trees on Earth.

However, climate change and human activities are having an increasing impact on this valuable area. About 17% of the primary forest area in the Amazon is experiencing negative impacts from human activities such as logging and fires. Rainfall in the dry season has fallen by a third, and climate change and deforestation have caused temperatures in the region to rise by 2.5°C. In order to accurately study the effects of these risks, scientists have taken various measures, and one way has become eco-acoustics.

What is ecoacoustics?

Ecoacoustics is a scientific field that studies the acoustic environment of nature and its effects on living organisms. Sounds produced by geophonic, biophonic and technophonic sources are an important part of the functioning of both natural and human-modified ecosystems. Passive recording is one of the most non-invasive technologies to study the acoustics of the environment, as it minimizes human interference and enables the collection of huge amounts of data. Ecoacoustics aims to understand the function and importance of sounds in the environment and to assess the influence of external factors on animal behavior and communication. Researchers use various types of sound recording techniques, including microphones and hydrophones to collect data.

Ecoacoustics as part of the international RAINFAUNA study

The use of eco-acoustics in the Amazon is part of the RAINFAUNA study, funded with £1 million by the Council on Foreign Relations. National Environmental Research Council (NERC). The project involves joint work by international teams of researchers from Lancaster University, Manchester Metropolitan University and the University of Exeter from the UK, the Federal University of Amazonas, the Brazilian Agricultural Research Corporation (Embrapa) and the National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN) from Brazil, as well as the National Museum of Natural History in France. Their goal is to collect data on the impact of climate change and human activities on rainforest animals. The scale of operations is enormous.

Scientists will try to determine the number of bird species living in the forest canopy using new modeling techniques that take into account differences in climate and vegetation. By collecting acoustic data, using microphones placed at appropriate heights, they will be able to indicate differences in the acoustic environment of different forest areas in varying climates. Analyzing this data, they will estimate the number of bird species and compare them between areas.

In addition, microphones will be installed in the forest soil to provide valuable information on the density of insects and other invertebrates.

Estimating bird densities will help determine the population size of species, while understanding the diversity and activity of invertebrates will reveal their important ecosystem services, such as leaf decomposition and soil mixing. The RAINFAUNA project opens the door to learning about and protecting the extraordinary heritage of the Amazon rainforest.

“Through the use of eco-acoustic monitoring and innovative modeling, enabling us to collect valuable data from large forest areas, we will for the first time be able to provide evidence-based estimates of the contemporary and future densities of these bird and insect species. This will yield results that will be invaluable for both scientific discovery and management of these precious rainforests,” Dr. Oliver Metcalf, an eco-acoustics expert at Manchester Metropolitan University.

Microclimate as a key indicator of climate change impacts on fauna

Another highlight of the work will be to study the relationship between microclimate and animals in the forest. This is an aspect that will help provide valuable information about the health of the forest and the response of the fauna to climate change and environmental disruption.

The temperature and humidity of the undergrowth and leaf litter are key to understanding the fauna of tropical forests, as they describe the conditions experienced by the organisms that live there. Researchers will use samples from 180 sites. They also plan to develop a microclimate model so it can map forest temperature and humidity. This will allow us to understand how bird density and insect activity are changing in space. And most importantly, it will help predict how the microclimate – and thus the fauna – will look in the future under different scenarios of climate change and forest disturbance.