superfast muscles for cooing doves
To coo, a dove's muscles have to contract and relax amazingly quickly.
To run fast, an animal’s muscles have to move fast. To sing, a bird’s muscles have to move even faster. That’s what a study of ringed turtle-doves says.
A ringed turtle-dove uses superfast muscles to coo.
|Judith S. Anderson|
Scientists have found high-speed muscles in a variety of animals. These tissues can contract and relax amazingly quickly. Among the very fastest are muscles in toadfish. These creatures make muscles in their swim bladders move very quickly to produce sounds. Rattlesnakes have superfast muscles in their tails, so they can shake, shake, shake.
When ringed turtle-doves (Streptopelia risoria) coo, they make a lot of very short, fast sounds in row. Researchers from the Netherlands and the United States suspected that the birds might have speedy muscles, too.
To find out, the scientists implanted tiny electrical devices in the structures that the birds use to make sounds. When the birds cooed, the electrodes indicated which muscles contracted and relaxed over and over.
These particular muscles control membranes in the throat. The membranes vibrate when air passes through from the lungs.
Ringed turtle-dove on the ground.
|© Bill Horn,|
Next, the researchers removed the muscles that control the membranes and tested them in the lab. They found that these muscles, outside of the bird, contract and partly relax in just 9 to 10 milliseconds. A typical animal muscle takes at least 100 milliseconds to do the same thing.
All sorts of other birds might have superfast muscles, the researchers propose.
Songbirds, in particular, tend to have complex songs. Birdsong researchers have already learned a lot about how bird brains work when birds sing. When it comes to chirping the melodies of springtime, though, muscle speed could be just as important.
Note: The ringed turtle-dove (Streptopelia risoria) is also known as the ringdove, ringneck dove, ring-necked dove, Barbary dove, laughing dove, and turtle dove.