About us: We own the Wild Birds Unlimited nature shop in East Lansing, Michigan,
a store that provides a wide variety of supplies to help you enjoy the birdwatching hobby.

This blog was created to answer frequently asked questions & to share nature stories and photographs.
To contribute, email me at bloubird@gmail.com.

Tuesday, January 13, 2009

Question of the week: Why don't starlings crash?

How do thousands of starlings fly without colliding?

Now that I’ve moved my desk to the front of the store, I am constantly distracted by a massive flock of starlings performing incredible aerial displays above the busy Lake Lansing Rd. You start to wonder why the birds never crash into each other or how the birds seem to always maintain their place despite the shifting shape and density of the flock.

Physicist Andrea Cavagna also asked those questions watching the birds overhead in his native Rome. He was so intrigued by the mystery that he organized StarFlag: Starlings in Flight, a multidisciplinary, multinational collaboration to study the birds' flocking behavior. The main aim was to determine "the fundamental laws of collective behavior and self-organization of animal aggregations in three dimensions," says Cavagna.

If the flock is under attack from a predator like a Peregrine Falcon, they will spread apart. At other times, when the flock is making a directional change, they will merge much more closely together. "They do these incredible maneuvers but they never lose birds, they are always with the flock no matter how drastically they change the shape or the intensity, they always stay together," Cavagna explains.

After one year of studying the data collected in the two previous years of the study, Cavagna said the researchers have come to the conclusion the birds base every movement on what their wing-mates are doing. "They always interact with six or seven birds irrespective of what is the distance of these seven birds," he says.

That means that after an attack has taken place, and the flock has expanded, it can regroup very quickly because cohesion doesn't rely strictly on the distance between the birds. "An interaction based upon the number of neighbors rather than their distance, implies rather complex cognitive capabilities in birds," Cavagna said in a news release.

Cavagna said the findings may have implications for the study of other animal groups and might shed light on human behavior. StarFlag's Jean-Philippe Bouchaud, a theoretical physicist believes the birds could also explain herding responses in human beings with a particular eye on stock-market panics. Individual people coordinate and imitate each other to create a collective phenomena. People are extremely influenced by their neighbors, by fashions and fads. They are looking for situations where the ways people interact and create a collective effect can be measured.

Starlings flocking is more complex, says Bouchaud, "because it's a three-dimensional organization of birds in space. But the idea is to work up from the behavior of individual birds to the behavior of the flock." The connection to studies of people is indirect, he adds. "Behind these projects is the same fascination with collective effects that glues the whole project together. We have a lot of things to share when we meet."

The following is a video of Starlings in Ot Moor, an area of wetland in Oxfordshire, South-East England, located halfway between Oxford and Bicester, before they roost for the night.
It was filmed by Dylan Winter a professional DVD film maker and Radio Journalist in the UK.


Dylan Winter said...

Thanks for metioning my starlings item on you tube

I was contacted by one computer man who said that the behaviour can be reproduced with about three lines of code

There is a computer prog called Boydz that makes the flocking behaviour

Some people take the murmurations as a proof of god

Very flattering as a cameraman to have filmed it but.... I believe they are wrong

There is a hi-def version cut to pachelbels version here



Wild Birds Unlimited said...

Thank you for the wonderful and informative video. I watched it over and over fascinated by these birds that people in our area love to hate. I like the hi-def version but I really like the other version where at the end you hear the amazement/excitement in your voice over a bird that most people overlook.

Your beautiful camerawork captured that feeling of wonder.

Dylan Winter said...

Thanks for that

Lovely to get back such heartfelt feedback

The web is a horribly honest place though

130,000 people have looked at the starlings item

3.5 million have looked at another item I shot called “Big trucks in western Canada”

It does seem that the average homo-sapiens still has knuckles that are worryingly close to the ground


Nolan Minor said...

I just don't understand why they don't do any damage with their droppings!

Claire Liparulo said...

We are heading into a time of year where we see something very similar here in Florida. It's one reason this is my favorite time of year. I used to lay out on the grass in our yard after a school day and look up at them. It's really beautiful.