The sexy sound of birds: The Science Lecture Series debuts its final lecture of the semester

A hummingbird displays its bioacoustic tail feathers while feeding from a bird feeder. (William Brawley Flickr/ Creative Commons)

A hummingbird displays its bioacoustic tail feathers while feeding from a bird feeder. (William Brawley Flickr/ Creative Commons)

The Science Lecture Series is a forum designed to allow Saddleback students and the neighboring community to attend a science lecture hosted by leading scientists in their field of study. These lectures are approximately two hours and cover a wide range of topics, all carrying scientific relevance and value. This provides students with a chance to become more interactive and informed about breakthroughs and research advances within the scientific community.

For the final lecture of the fall semester Dr. Chris Clark an expert in animal flight, bioacoustics, biomechanics and courtship displays discussed his research on small birds, in particular hummingbird courtship displays that use biomechanics to produce bioacoustics. His research began with the Anna’s hummingbird and the common notion that all noises heard from the animal where vocal, like most other mammals.

A rather rare topic in the science community, one would wonder how an individual could take such great interest in the subject? A love for small birds, or sounds caused my aerial vibration?

“I had no interest at all,” Clark said. “It just fell into my lap.”

Through extensive hours in the field “literally,” Clark implemented many technologies and techniques to collect sound data and explain where it came from. His first scientific technique was to bait male hummingbirds using dead female hummingbirds perched on a limb and observe the males courtship display.  This mating display is a swift dive by the male followed by a short bioacoustic sound. He later perfected his hummingbird catching techniques and began using live females once the males realized their potential mate was unresponsive and quickly lost interest.

“ It was to interesting to pass up,” Clark said.

Clark captured the Anna’s hummingbird’s mating behavior using high-speed cameras, special microphones and a science laboratory with a wind tunnel system. Clark would place a feather or feathers in the wind tunnel in what he later concluded was the wrong angle to measure the maximum vibration and sound particular tail feathers made. The wind tunnel experiment also tests the relation of the feathers structural relevance based on how the surrounding feathers manipulate the vibrations of another feather to generate a specific sound.

The use of this technology helped Clark conclude that the sounds made by the birds observed and tested were a result of the feathers and their unique structure to produce specific bioacoustics using biomechanics while in flight.

The silent flight of owls was also briefly discussed which is thought to use the same principles discovered that make bioacoustics, can also be used to decrease sound as well.

While biomechanics has been widely studied, bioacoustics is a new filed of study with its findings still not yet making its way into new technological advances relating to sound vibrations and wind.  With more research being conducted, bioacoustics will carry many uses that will eventually be used to improve our technology and daily lives.

Photo used with CC BY 2.0