The song of the birds fades | The eavesdropping of birds in the world’s forests tells us that the winged have died down – songs are also recorded in Evo

If wants to study birds properly, sometimes you have to climb a tree.

At the beginning of the summer, the British project manager Lawrence Whittaker nimbly climbed a tall tree in the Evo National Park in Lammi.

He climbed habitually with the technique normally used when climbing thick trees in the tropics. He shot Isa with a device similar to a slingshot around the branch to the rope, which he used to climb to the top.

Whittaker didn’t climb the tree for fun, he went to install a device on the top that listens to the birds.

Evo started a project in June, where researchers collect sound samples with 60 listening devices during the nesting season. Whittaker works for the international environmental organization Rainforest Connection.

Evo’s project is a joint project of the Land Survey, environmental organization Rainforest Connection and Huawei Finland.

Dozens even before the Evo project, automatic devices listen to birdsong in Finnish forests and collect sound data for researchers.

The environmental organization Rainforest Connection has forty listening sites around the world. In many places, listening devices also monitor poachers and illegal loggers.

There are listening devices to help the forest police, for example, in the crater of Astron in Italy and in Orbetello and Burano in Tuscany. They are so-called biodiversity centers with diverse nature.

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The result was clear. Birdsong has decreased. At the same time, the birds’ concert has become one-sided.

Research accelerated observations of the decline of birdsong in different parts of the world.

A group of researchers from more than 20 countries has done summary aearlier, from audio data collected from the 1990s. From Finland, a zoologist from the University of Helsinki, chief superintendent, participated Aleksi Lehikoinen.

The researchers cleverly combined recordings of the birds’ typical song with databases of bird sightings in North America and Western Europe. They were able to compile a soundscape in a certain spring in a certain place, even though no one was necessarily recording at that time.

Soundscapes accumulated in more than 200,000 locations over a period of 25 years.

The long term is important. Bird stocks often vary a lot, so a period of 2–3 years tells little. The time frame of a quarter of a century, on the other hand, already reliably shows the direction of development.

The study was published Nature Communicationsin the journal.

Result was unambiguous. Birdsong has decreased. At the same time, the birds’ concert has become one-sided. In Finland, for example, the song of the willow bird and in America the song of the woodpecker has decreased.

To the soundscape according to the researchers, the reduction of the rich song of the ruffed grouse or the willow bird is probably more effective than the rough sounds of crows and seagulls.

The beauty of birdsong is of course in the ears of the listener. It should still be clear that when the willow bird leaves the crowd, nature’s spring concert becomes one-sided, with all due respect to crows and seagulls.

Likewise, music would be impoverished if violins disappeared from an orchestra, with all due respect to drums and pianos.

worrying the result increased the researchers’ desire for information even more. “We strongly recommend increasing field recordings of soundscapes and their systematic analysis,” the researchers wrote in their article.

Research has accelerated. Rainforest Connection is recorded birdsong in the Amazon region and Puerto Rico.

Brazilian and American researchers collected basic information from the Amazon floodplain about the habitat of many birds and which species are most vulnerable when hydropower is built. The report was published In The Wilson Journal of Ornithology.

In Puerto Rico, listening helped define the home range of the endangered Puerto Rican gannet so that protection can be targeted in the right place.

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Bioacoustics, which studies the sounds of life, is growing at a rapid pace, also thanks to new technology.

in Finland automatic sensors are currently recording the sounds of the forest in eight locations, also in the international one In the Lifeplan project, which is run by the University of Jyväskylä. Each point has three listening devices.

There are thousands of similar devices installed all over the world, but not all of them record sounds at the same time. This spring, about 550 devices recorded sounds.

Bioacoustics, which studies the sounds of life, is growing at a rapid pace, also thanks to new technology.

In recent years, microphones, data networks and artificial intelligence methods for data processing have improved so much that it is possible to collect comprehensive information about birdsong over large areas and over a long period of time.

In Evo, birdsong is recorded on memory cards, which the researchers collect from time to time. There is so much data that transferring everything wirelessly would be difficult, especially in the forest, where the field can be weak.

The sensor that Whittaker put on the tree, on the other hand, gets its energy from solar panels. The collected data goes wirelessly to Huawei’s local cloud for use by researchers.

For enthusiasts mobile phone technology has given new opportunities. With a smartphone, you can record and identify birds and send sound samples to researchers.

The Lifeplan project was made possible research, where birdsong recognition was further refined. University of Jyväskylä published by in April of the application Spring of migratory birdswhich everyone can use with a smartphone.

The researchers made the application by fine-tuning previous bird models with training material produced by Finnish hobbyists.

They participated in two ways. They judge whether the given sound sample is the song of a particular bird. Second, they listened to ten-second clips and reported which birds they heard.

In less than a year, more than 240,000 sound samples and more than 5,000 clips were recorded. More than two hundred bird watchers participated in the project. Sound data for the evaluation was collected in ten locations in Southern Finland. Three tape recorders worked in each location.

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“Researchers can learn to understand the structure of the forest, the diversity of species and the interaction relationships more deeply.”

Researchers combined global and local audio data and built a convolutional neural network for recognition

Convolutional neural networks are popular machine learning methods for various recognition tasks. An object, image or sound pattern is recognized feature by feature.

Comparative testing showed that tuning according to the local soundscape improves the result.

It is precisely in identifying Finnish birds that “Migratory Bird Spring” is more accurate than foreign applications, for example the widely used BirdNet, which is maintained by the American Cornell University and the German University of Chemnitz.

in Finland the focus is on securing diversity.

Researcher at the University of Helsinki Hanna Rosti uses sound data collected from Evo in bird nesting research. Above all, I am interested in the study of the drumming duet of the northern sea.

He has previously listened to nocturnal animals in Kenya and Tanzania.

“My research in African forests has been enormously useful. There I have learned to use tape recorders and microphones, and I have analyzed huge amounts of audio material using different programs.”

“Furthermore, I have combined audio materials with materials collected by other researchers, which then raise the research and the modeling done from it to a whole new level.

The intention is to combine the acoustic bird data collected with Evo with other data produced by the Land Surveying Institute.

“Through that, researchers can learn to understand the structure of the forest, the diversity of species and interactions more deeply,” says Rosti.

For the first time, the Land Surveying Institute also receives acoustic data from Evo for science and forestry. In the past, information has been collected by satellite imaging and laser scanning, which utilize electromagnetic radiation.

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“Private forest owners have mainly been interested in participating in the research.”

Bird song is also of interest to both international companies and private forest owners.

The attitude of Finnish forest farms to research was measured when forest inventory data was expanded with, among other things, acoustic data.

Along with game cameras and other devices, listening devices are also installed in the experimental areas. This summer and next summer, the researchers will collect sound data from 135 test areas, one week at a time.

Permission to install the equipment must be requested from the forest owner. That’s what researchers usually got.

“Private forest owners have mainly been interested in participating in the research, and the reception has been positive,” says Dr. Mira Kajanus from the University of Jyväskylä.

The Natural Resources Center Luke, the University of Jyväskylä, the Environmental Center Syke and the Central Museum of Natural Sciences Luomus are participating.