The decrease in the diversity and intensity of early morning bird songs is a result of biodiversity loss and associated change in bird communities. Because birds are heard more often than people see, the declining quality of the natural bird choir may be an important way for people to experience biodiversity loss.
Lark or crow
The quietness of the bird group is generally strongest in areas where the number of birds and / or bird species are low in fertility. However, the original structure of the local bird community and the extent to which the call and song characteristics of the different species complement each other also play an important role. The loss of Skylark and the Nightingale, for example, has a greater impact on the complexity of the bird chorus, which sings lush and complex songs, than on the loss of the harsh calls of cormorants or ducks. It depends on how many Skylarks or Nightingales are native to the site, as well as what other species are.
Soundtracks
Records of complete bird singers are low, especially in past situations. So the researchers used a new technique to reconstruct the soundtracks. This includes linking data from bird numbers over the past 25 years to audio recordings of individual species in the wild. This resulted in a historic series of reconstructed audios from more than 200,000 locations. “It should be one of the largest citizen science exercises in our field,” says Chris van Turnhouth of the Sovon Vogelonderzoek Nederland. “Records were collected by many volunteers, not only because of all the long-term numbers on the two continents, but also because of the use of sound.”
Measure by sounds
To compare structured sound terrains, the researchers used different measures. Diversity was determined by measuring how many different sound frequencies occur in the recordings. The greater the diversity of the species, the greater. Proportional frequencies, on the other hand, indicate the dominance of a certain number of organisms. The amount added within different frequencies is related to the size of the birds.
Curious as to how such a structured sound system sounds? Ask for an example From a place in the United Kingdom.
Source data
Annual bird counts from North America from the North American Breeding Bird Survey. In Europe, they come from the Pan-European Public Bird Watching Program, which includes the number of zoons. Breeding bird watching program Pitch. Audio recordings of more than 1,000 species have arrived Xenon-Singing, An online database of bird sounds and songs.
