Like something out of a science fiction movie, Scott Davis’s remote controlled “octocopter” hovers above the ground and then soars over treetops, attracting the attention of onlookers who glance skyward.
With eight arms that branch out of a gear-shaped centerpiece, each topped with black propellers, and wheels affixed to four legs to ensure a soft landing, Davis’s invention resembles some sort of alien aircraft. But the Rutgers University–Camden senior isn’t interested in something from out of this world. He designed the drone to study flight patterns of flocks of birds.
“You see this cohesiveness among flocks of birds in flight, but how tied together are their movements,” asks Davis, a U.S. Navy veteran and Rutgers–Camden biology major from Folsom. “How does each member of the flock affect the others in order to maintain cohesive movement?”
Rather than observe the birds from the ground, Davis is taking his research to the air. He designed and built the octocopter drone, which carries two cameras to record birds in flight. The drone can fly more than 700 feet high and Davis controls it remotely.
“By recording the birds in flight, we’ll be able to generate a three-dimensional map of individual positions within the flock to allow us to measure the distance between each bird, analyze their motions, and see how fast one bird responds to another bird’s movement,” Davis says.
The Rutgers–Camden senior is interested in the dynamics of the flock and any physiological mechanisms that allow a bird to respond to another’s movements while in flight. Davis says, “We hope to learn what birds are using to conserve their position in small and large groups.”
He is particularly interested in starlings, which are known to gather in flocks called murmurations. It’s quite common to observe hundreds of thousands of starlings in one murmuration. To see them fly together is like watching a massive moving, dark abstraction in the sky.
“We have a pretty good idea of the group dynamics of flocks of larger birds, like geese,” Davis explains. “We know that a V-formation is aerodynamically advantageous to geese, and that a goose flying in the front of a V-formation has a much faster heartbeat than a goose in the back. As they change position, their heart rate will change. But starlings have the ability to form these massive murmurations and it actually looks as if it’s one fluid movement. Imagine holding hands with thousands of other people and running together as one cohesive unit. That’s what these murmurations are like.”
Davis says the birds may come together in this massive flock to gather food or defend against predators. “We want to know what the rules are per bird for participating in this activity and from that we can try and understand the rationale behind it. It’s a hard phenomenon to explain.”
William Saidel, an associate professor of biology at Rutgers–Camden who is advising Davis on his project, points out that this work is expressive of a relatively new facet to the study of groups.
“At the present time, we think murmuration — or the shape of smaller flocks found locally — is an emergent global property of the flock resulting from local interactions of interwoven groups of six of seven neighboring individuals,” Saidel says. “Since each individual is a member of multiple groups, the flight instructions propagate exceedingly fast throughout the flock.”
To better understand these patterns, the Rutgers–Camden researchers intend to observe them from the side and from above. Davis designed the drone himself, from the platform’s mechanical framework to the electrical control systems. He is working in a research group that includes Saidel and Benedetto Piccoli, the Joseph and Loretta Lopez Chair of the Department of Mathematics at Rutgers–Camden, as well as several other students.
The research project combines biology with math, computer programming, and aeronautical engineering and is being funded in part by the participants and by grants from the National Science Foundation and the Rutgers Undergraduate Research Fund.
“Rutgers–Camden has given me an opportunity to work on a project like this while combining so many different disciplines and that’s an experience you just can’t get anywhere else,” Davis says.
To see a test flight of Davis’s octocopter on the Rutgers–Camden campus, click on the video below. Video courtesy of Robert Emmons, associate director of the Digital Studies Center at Rutgers University–Camden.