Each year in southwestern Nova Scotia, a barely noticeable series of nocturnal chirps signals the presence of a bird route in the sky above.
A citizen-focused project is now using new technology and AI to map these migratory routes and other important habitats in the province.
The Listening Together project uses inexpensive audio recorders, combined with machine learning software, to record and analyze bird calls.
Project founder John Kearney said the increasing availability of technology enables a project that not only provides data, but also opens up greater opportunities for communities to directly participate in research.
“Technology used to be very expensive, and only a few people could afford it. But now for US $ 50 you can have your own complete recording unit. on the ground, ”Kearney said.
“It’s not just about going out and watching and seeing how biodiversity is increasing or decreasing, but also about learning from each other, how we are not only going to transform ourselves, but our world.”
Bioacoustic monitoring has a long history in Canada. In 1949, the first records of marine mammals – the belugas of the Saguenay River in Quebec – have led to a significant increase in research on whales, and acoustic monitoring on land has been increasingly popular since the 1990s.
But the Listening Together project takes advantage of technological developments in recent years, which have made this type of monitoring much more accessible.
The project focuses on two species at risk: the Canada warbler and the Leach storm-kernel. The latter is considered threatened.
Kearney said habitat conservation often focuses on breeding habitat, which only harbors a species such as the Canada warbler for part of the year.
“It is very important that we preserve the habitat of these endangered species throughout their annual cycle. So we’re looking at it in terms of the habitats we need to protect so that these Canada warblers can get the nutrition they need along the way? “
AudioMoths keep watch at night, when warblers migrate, emitting buzzing and hissing sounds as they fly.
For Leach’s Storm Oceanite, where the focus is more on identifying nesting sites on remote islands, Kearney said this type of monitoring is particularly important, to track changes in the species since beginning of the period in which it was designated as threatened.
Until recently, bioacoustic habitat monitoring was an expensive and time-consuming endeavor, requiring loggers that cost thousands of dollars and generate files requiring specialized analysis.
For this project, however, Kearney is relying on AudioMoths, an inexpensive open-source audio recorder first created by researchers at the University of Southampton in the UK in 2017, to monitor the sound of gunfire – and therefore poaching – in nature reserves. in Belize.
The recorders, which are the size of a bar of soap, can be placed in a plastic sandwich bag to keep them dry, and hung on a tree or pole, where they record sound on their own.
Kearney said that, through Listening Together, community members have placed AudioMoths all over Kespukwitk – the Mi’kmaw name of the region – for the detection of the Canada Warbler and on two coastal islands for the Storm Oceanite. by Leach.
Tony Millard, a bird watcher and director of the Nova Scotia Bird Society who lives in Cape Forchu, contributed to the project. He said the loggers allow citizens to be directly involved in data collection.
“That’s it, this wonderful little listening device with microchip elements inside. And then you ask someone once a month to take out the chip and have a program on your computer, plug it in and look at the data. It is not that complicated. . “
Some of the new programs that the project uses for analysis, such as BirdNet – a research project from American and German universities – or Merlin bird identifier, use machine learning to identify bird calls based on records, allowing non-specialists to be involved in the interpretation of at least part of the data.
These programs can also be used to spot bird calls from hundreds of hours of recordings (in other cases, spectrograms – a visual representation of sound frequencies – can be analyzed by a trained person, to identify birds at species level)
Millard said these automated approaches could be particularly useful in the years to come, for documenting changes in species distribution due to climate change.
“There is so much technology in the future [that] we’re going to have our birding ride, to help us out, ”Millard said.
Phil Taylor, a professor in the Department of Biology at Acadia University who participated in the project and led other citizen science monitoring projects – including the deployment of AudioMoths volunteers across New Brunswick last summer to monitor Black Scoter migration – said this kind of inexpensive bioacoustic monitoring extends both the geographic scope of the research and its reach in the general population.
“It totally changes what you can think of and what you can do,” Taylor said. “And this is a way to [people] contribute, and that engages them, and then when you start writing things up and publishing the analysis and the summaries, those people are interested. “
Taylor said it is especially important to use these tools to focus on migratory habitat, because while breeding habitat is well documented and therefore shapes policy, migratory habitat is less understood, even if the migration is often the most dangerous time for birds.
“So better understanding where they go and where they stop can help us guide policy towards habitat protection during migration.”
“It’s for everyone”
So far, the Listening Together project has identified an area in Digby County that is a milestone for Canada Warblers as they prepare to cross the Bay of Fundy, and is now using support from a fund intended to establish areas of potential protection in the province and will survey other areas that provide habitat for migratory birds.
In a statement, the Environment Ministry said it is important that areas of high biodiversity value be identified, to guide decisions regarding provincial land protection.
Kearney hopes that in the future, project participants will continue to do more than collect data, as input from the perspectives of project partners, which include the Acadia First Nation and academic institutions, as well as a cohort Growing number of people who have become more interested in exploring nature since the start of the pandemic, increases the potential impact of the work.
“This desire to conserve nature goes hand in hand with its understanding and relationship to us, as interdependent with these plants and animals,” Kearney said.
“I sincerely think that if we are going to solve this ecological crisis that we have, science alone is not going to do it, we are going to have to understand it from a cultural, spiritual and scientific point of view. And so I think that kind of understanding isn’t just for scientists. It’s for everyone. “