Earth’s birds make a variety of calls and convey various messages. petite Black-capped tit that makes a high noise It tells the predator to scram. Hungry green woodpecker chicks often Buzzing sound when waiting for food. Many different species use special songs to find a mate, Warbler They are known to sing just for fun.
Ornithologists, citizen scientists, and bird watchers alike are familiar with this large repertoire, but some of the environmental conditions that contribute to these sounds are less understood. To help, a team at the University of Wisconsin-Madison recently used more than 100,000 audio recordings from around the world to study some of the factors that influence bird calls. They found some patterns in how habitat, latitude, beak size, body size, and terrain affect the birds and at what frequencies they make certain noises. . For more information on the survey results, please visit Research recently published in journals Proceedings of the Royal Society B.
From local to global
Previously, the hypothesis regarding its role was beak shape, geographybody size, relationshipshabitat play with bird calls has been tested on a smaller scale. in this new researchthe team sought to test these hypotheses and see if they held true on a global scale. The team analyzed audio recordings of bird calls recorded by participants around the world and submitted to the report. An online nature sound repository called xeno-canto. The recorded content is 77% of known birds.
Habitat and latitude
The team discovered that Habitat appears to influence sound frequencies Birds behave in some unexpected ways. Ecosystems with large amounts of water force produce a near constant level of white noise at lower frequencies. Here, the researchers found that birds tend to emit sounds at higher frequencies to avoid them being drowned out by water.
Additionally, birds that live at the same latitude make similar calls. According to the teamobserving this pattern on a larger, global scale is an important piece of the puzzle for understanding how bird calls evolved.
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size issue
both Beak shape and weight is also important. Generally, smaller birds produce higher frequency sounds and larger birds produce lower frequency sounds. This new analysis proves this hypothesis correct, but also adds additional data on the nature of the relationship between sound, beak shape, and body weight.
Worldwide, Small birds tend to have a wide range of frequencies. They use these sounds as a protection mechanism, and smaller, weaker birds can benefit from having such a range of sounds. Higher frequencies help them communicate with fellow birds of the same species. of Lower frequencies can act like a bit of camouflagewhich can trick predators into thinking the bird is larger and scarier than it actually is.
surrounded by noise
This research also led to a better understanding of Earth’s soundscape. These make up all the sounds heard in a particular area of land or sea. Although soundscapes are often used in conservation research, it is still poorly understood what environmental forces govern soundscapes.
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“In the tropics and around the world, larger birds tend to be hunted for their meat,” says study co-author Satya Chandra Sagar, HS, a doctoral student at the University of Wisconsin-Madison. stated in a statement. “big bird” [tend] If you make a call on a low frequency and no sound is found on the low frequency, [conclude] There may be more hunting in this landscape. ”
Sagar hopes this study can be used as a platform for future research to monitor ecosystem health through soundscapes. He plans to use 24-hour soundscape recordings to understand whether some birds change both the timing and frequency of their calls to communicate with mates in noisy landscapes. is.
