Sounds provide important environmental cues

Sounds provide important environmental cues Today’s Video of the Day from the Smithsonian Tropical Research Institute investigates the difference between regular noise and sounds that provide important environmental cues.

While it is known that bats require twice the amount of energy to fly once they become wet, the experts wanted to determine if rain may also hamper their ability to hunt.

The researchers studied two species of bats that hunt in very different ways and at different times of the day.

The team played recordings of heavy downpours and set up surveillance cameras to monitor how the bats would respond.

The study revealed that both bat species relied on sounds to decide whether or not to leave the roost. All the sounds of a given place and time, and the factors that influence their transmission, make up an acoustic environment. How animals filter or perceive the sounds creates a soundscape. The four broad categories of acoustic-ecology research and their important links are illustrated in figure 3. Like the amphibian chorus, biotic sounds may unintentionally provide cues for other species. One well-studied example is the coral reef, in which the biotic sounds emitted from fish, urchins, shrimps, and other animals are important settlement cues for planktonic larvae of fish and invertebrates. 

Unintended sounds do exist in nature, like the footfalls of an animal, but such sounds provide vital cues for some animals and are considered sounds to the receiver and noise to the producer. Numerous terms have been used to categorize different sources of sound. For example, sound and noise are often used interchangeably to describe an acoustic source. A common definition of noise is unwanted sounds that interfere with a signal of interest. Noise, however, is not a purely subjective designation. Any sound that serves no function is noise.

—

By Chrissy Sexton, Earth.com Staff Writer

Video Credit: Smithsonian Tropical Research Institute