How seabirds hear each other and navigate in space: scientists say they use infrasound
Wild animals spend most of their lives in search of food, for which they travel great distances. In this regard, seabirds have no equal. For example, Arctic terns migrate annually from the Arctic to the Antarctic and back, and snowy albatrosses (Diomedea exulans) make journeys equivalent to ten flights to the moon and back in their lifetime. However, scientists have not come to a definitive conclusion as to how the birds navigate the surrounding space while traveling such long distances.
The Economic IndiaTimes reports that recent studies have shown that seabirds use low-frequency sounds to determine their flight path and search for food.
SSPDaily told about infrasound, which is inaccessible to the human ear, but which they have found to be well heard over long distances.
How does infrasound help birds survive?
Many birds, including large ones, can pick up low-frequency sounds. What does this look like in practice for albatrosses?
The high activity of sea waves generates infrasound, which indicates that fish are rising from the depths to the surface. This creates upwelling, which is a good food source for birds.
High wave activity also indicates strong winds. And since they are the main driving force for albatrosses' flights, being able to know about it is vital for them.
This is also the sound of waves crashing on the coastline. And, as you know, many coastal seabirds use the coast to choose a flight route and find their way to their nesting colonies. Thus, infrasound indicates the location of static objects and provides seabirds with important information over long distances.
What did the scientists find out?
Scientists obtained data on the albatrosses' movements using a network of sensors installed by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). Thus, they received precise information on how albatrosses decide where to go next.
As it turned out, the birds chose the direction with the loudest infrasound, which generally confirmed the theory that they use it to find food and minimize energy consumption for movement. However, it is still difficult for scientists to say why albatrosses are interested in the loudest areas.
The question of which organ in the birds is responsible for receiving the low-frequency signal remains open. The problem is further complicated by the fact that it is technically difficult to take a wandering albatross to a laboratory and create a large enough sound chamber for experimental tests.
At the same time, other species of seabirds can live in captivity, and it is likely that research will move in this direction in the near future.