Super-fast vocal muscles control song production in songbirds

Songbirds use complex song to communicate with one another. Many species are able to modulate sound faster than ordinary vertebrate muscles are able to contract. Reporting in the July 9 issue of the online, open-access journal PLoS ONE, Coen Elemans and colleagues at the University of Utah found that the European starling (found throughout Eurasia and North-America) and the zebrafinch (found in Australia and Indonesia) control their songs with the fastest contracting muscle type yet described, the so-called superfast muscles that can produce work at frequencies over 100 Hz. The vocal muscles of songbirds can produce work up to frequencies of 250 Hz and can contract and relax in 3-4 ms, which is a 100 times faster than it takes to blink an eye. Superfast muscles were previously known only from the sound producing organs of rattlesnakes, several fish and the ringdove.

Elemans and colleagues now show that songbirds have also evolved this extreme performance muscle type, suggesting that these muscles, once thought extraordinary, are more common than previously expected. The researchers also show that superfast muscles provide more precise and faster control of song modulations in birds than previously thought physically possible.

Source: Public Library of Science