Sounds That Matter: How Passive Acoustic Monitoring Transforms Science and Benefits the Community

While the melodies of birds bring joy to many, for scientists studying their songs and sounds, it’s a clear indication of the health of the ecosystems they inhabit. The communities involved in the Conserva Aves Initiative in Colombia, led by the American Bird Conservancy, Audubon, Birds Canada, BirdLife International, and the Latin American and Caribbean Network of Environmental Funds (RedLAC), will now have the opportunity to contribute to citizen science through Passive Acoustic Monitoring (PAM), an additional tool for monitoring the well-being of protected areas under their care.

But what is it all about? In practice, PAM consists of using recorders installed in the forest to collect sounds at programmed time intervals, which are then processed by specialized software to identify the vocalizations of bird species using artificial intelligence algorithms.

“Each reserve has certain bird species of interest, identified as part of the prioritization studies of areas to be protected by Conserva Aves. Passive acoustic monitoring allows us to continuously take the pulse of bird populations without having to be physically present in the field,” explains Jorge Velásquez, Director of Science for Audubon Americas.

Recently, a workshop was held in Darien, a community in Valle del Cauca, Colombia, to launch a pilot acoustic monitoring project for the Conserva Aves Initiative, which aims to protect two million hectares of new subnational protected areas in Latin America. In Colombia, 18 protected areas have already been established or are in the process of being established as part of this program, and three of them sent delegates to the workshop, who provided tools for establishing acoustic monitoring. These are: the Fundación Darién, which has been working on a process to consolidate civil society nature reserves with private landowners; the Fundación Trópico, which manages the Alto Calima Integrated Management District, which was declared a protected area in May 2024; and Felca, which manages the Río Ñambí Reserve, where there is a conservation process focused on hummingbirds.

“These organizations are primarily focused on strengthening local governance in their areas. Depending on the conservation category or the figure they manage, the dynamics change a bit. For example, in the case of Alto Calima, which is a regional area, it requires interaction with several institutional and community actors. In the case of Felca, a reserve owned by the organization, the consolidation has taken many years and is currently one of the most interesting areas for bird conservation in Colombia,” explains Sebastián Orjuela Salazar, coordinator of Fondo Acción, Conserva Aves’ national partner in Colombia.

What is the benefit of knowing which species are present in a protected area, to the stewards of that area?

Jorge Velásquez points out that “knowing what species are in your territory is like knowing how much money you have in the bank. If you know what species are in your territory, you can manage more resources for conservation. For example, if there are endemic or threatened species”. But that’s not all, it’s also possible to know how to protect the territory from certain threats, such as those resulting from the expansion of the agricultural frontier or the development of infrastructure works. In addition, the number and diversity of species is a great ally for the promotion of a reserve, something very attractive for birdwatchers or birders who are constantly looking for new destinations to find their target birds.

“Knowing the wealth of biodiversity that lives next to you helps people to take ownership of their territory, to be proud that they live in an area where there is tangible wealth. When we know that there are a large number of bird species, especially when there are species that are not so common, it is necessary to develop strategies to conserve their ecosystems,” says Santiago Ruiz Guzmán.

The bioacoustic monitoring workshop, which provided participants with equipment and instructions on how to use it in their areas, also gave them tools to set goals and objectives based on the area they were in and to develop strategies for knowing the best times of year to monitor. “For example, if we want to know long-term population trends, we may need to monitor once a year for many years; but in some cases we may just want to know what times of day a bird is singing, so a recording scheme that covers all hours of the day will allow us to answer that question. In other cases, we may be interested in knowing when migratory birds arrive and when they leave, so it would be important to cover the boreal and austral migration periods,” says the scientific director, who is also implementing this system in the mangroves of Bahía de Parita and Bahía de Panamá, in Panama, as part of the Panamá, Patrimonio Natural Azul.

“What we have learned is something very innovative, very new for us, because it allows us to take advantage of these new technologies to understand a little bit more about the dynamics in the ecosystems. We know that we have a great diversity of birds, but we know very little about them, about their vocalizations according to their behavior. The idea is to put into practice what we have learned with the equipment that they gave us and to articulate it with the monitoring that we do with the mist nets, which is a 10-year monitoring that we have programmed and in which we do one session per annual season of one month. We hope that this acoustic monitoring will complement the information we generate to evaluate the health of the bird populations,” said Cristian Flores, director of Felca.

Taking notes

As part of the training, participants from each reserve received an acoustic monitoring kit to reinforce the knowledge gained during the workshop and to initiate a three-phase pilot project. The first phase, which ends this January, includes familiarization with the equipment, management and analysis of acoustic monitoring data. In the second phase, which will last six months until mid-2025, 10 to 20 recorders will be deployed per reserve to determine the sampling effort needed to monitor the bird populations of interest. In the third and final phase, a second version of the workshop will be held to share experiences, refine protocols and train the second cohort of Conserva Aves beneficiaries in passive acoustic monitoring. Ultimately, the idea is to create a monitoring network in all protected areas with the support of Conserva Aves.

So far, six PUCs and six audiomoths have been deployed in the three reserves. The results are promising: in just 15 days of sampling, the PUCs detected an estimated 337 bird species, including 33 migratory, six endemic and five threatened species. The reserve with the highest number of species detected was the Alto Calima Integrated Management District (187 species), followed by the El Porvenir Bird Reserve Node (159 species) and the Río Ñambí Reserve (140 species). However, this data is not definitive, since the sampling periods in each site were different and the species identifications have not yet been validated by experts. However, the results obtained so far show the commitment of the communities to apply the knowledge acquired in the workshop to improve the management of their reserves.