BrainStuff Classics: How Do Starling Murmurations Work?

Starlings flock in swooping, harmonious groups of thousands of birds called murmurations. Learn how these birds pull off such an amazing feat through simple actions in this classic episode of BrainStuff, based on this article: https://animals.howstuffworks.com/birds/starling-murmurations.htm

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Episode Transcript

Speaker 1 (00:01):
Welcome to BrainStuff, a production of iHeartRadio. Hey, BrainStuff. Lauren
Vogelbaum here with another classic episode for you. In this one,
we dive into the startling simplicity behind the complex flight
displays of groups of starlings. They're so impressive that researchers
are using them to help power other complicated processes. Hey, BrainStuff.

(00:27):
Lauren Vogelbaum here. Individually, a European starling is a common blackbird.
That's it. Starlings are short and thick with dark feathers
and long pointy bills. If you live in North America
or Europe, you've seen them, though birdwatchers have spotted them
throughout most of the world. More than 200 million live
here in North America alone, singing their chirpy songs and

(00:49):
being to many backyard growers and full-time farmers a bit
on the pesty side. Collectively, though, starlings transform into something
else entirely. Together, in flight, in mesmerizing flocks that sometimes
number in the hundreds of thousands, they are a breath-stealing wonder,
a pulsating, swooping, harmonized whole, seemingly defying the laws of

(01:09):
nature while defining nature itself. To watch a murmuration of
starlings in midair— that' s what the flocking behavior is called, a
murmuration— is to experience firsthand the power and mystery of the
natural world. We spoke with Mario Pessendorfer, a postdoctoral associate
at the Cornell Lab of Ornithology, who's also a research
associate at the Smithsonian's Migratory Bird Center. He said, I

(01:33):
think that the core feeling is a sense of awe.
The spatial scale of something that's moving very rapidly, which
we are utterly unable to do, and the visual patterning
that occurs when a lot of individuals are doing the
same thing really mesmerizes us. Memorations spark curiosity. And they
spark scientists like Pessendorfer to figure out how swarming animals,

(01:54):
like bees and birds and fish, can better our own lives.
In the 1930s, famed ornithologist Edmund Sellis suggested that birds
moving in murmurations were using some sort of telepathy to
transmit their flying intentions. He wrote in his book, Thought
Transference or What in Birds, they must think collectively all
at the same time, a flash out of so many brains.

(02:16):
As the years wore on, we found out that that's
not quite it. In the 1950s, scientists studying insects and
fish and other collective animal behavior posited that group movement
is more of a stunningly fast response to others in
the flock or school or swarm rather than some innate
mind-reading ability or a command from a group leader. The

(02:36):
authors of a 2015 paper published in the journal Proceedings
of the National Academy of Sciences wrote, It's the rapid
transmission of local behavior response to neighbors that enables such
startling synchronicity. Piesendorfer said, there's two ways that you can
elicit large group behavior. You can have the top-down control
where you have some kind of leadership or some kind

(02:56):
of top-down mechanism. Think of a rock show. You have
the rock star in the front and he starts clapping
his hands and the whole stadium starts clapping. But these
murmurations are actually self-organized, meaning that it's the individual's little
behavioral rules that make it scale up to the large group.
In order to understand this behavior, we have to go
from the local scale, what the individual is doing, what

(03:17):
are the rules that the individual is following, to the
global scale, what is the outcome? In 2013, a mechanical
and aerospace engineer and her team from Princeton collaborated with
physicists in Italy to study murmurations. Naomi Leonard, the Princeton engineer,
said back then, In a flock with 1,200 birds, it's
clear that not every bird will be able to keep

(03:39):
track of the other 1,199 birds. So an important question is,
who is keeping track of whom? The Italian physicists used
more than 400 photos from several videos to find out,
plotting the position and speed of birds as they flocked.
From that, they built a mathematical model that identified the
optimal number of flockmates for each bird to track. It

(04:02):
turns out the magic number is seven. Each bird keeps
tabs on its seven closest neighbors and ignores all else.
Considering all these little groups of seven touch on other
individuals and groups of seven, twists and turns quickly spread,
and from that a whole murmuration moves. Though it looks
coordinated on a large scale, the individual birds are concerned

(04:24):
with only three aspects of their flight and the flight
of those around them. These factors have been described in
several ways, but they boil down similarly. They are an
attraction zone, an area where you're going to move toward
the next bird over, a repulsion zone, an area where
you don't fly because you'll interfere with another bird and
you'll both fall, and angular alignment, meaning that you're following

(04:46):
a neighboring bird's directional movement. Pessendorfer said, depending on how
you change those three parameters, you can get everything from
those barrel-looking baseballs that you get in ocean fish to
loose-looking insect swarms to highly, highly organized fish swarms and murmurations.
all in those three little parameters. Scientists believe these birds
flock in the first place to confuse and discourage predators

(05:09):
through their sheer numbers, with the noise such a flock
makes and, of course, its motion. Some communication between birds
may be happening too in murmurations, say pointing out good
food sources, or the birds may simply be keeping warm.
What may be most stunning to mere humans is that
these birds react so quickly and do so in such synchronization,

(05:30):
if not immediately, within a couple flaps of a bird's wings.
They move almost as one in a type of lockstep or,
as it were, block flap. But how? Birds can take
in certain information around them and process it much more
quickly than humans. They see faster than we do. They
basically have a higher frame rate. Back in 1986, Craig Reynolds,

(05:53):
an MIT-trained computer scientist, built computer models of bird flocking
and fish schooling in something he called Boyds. These programs
provided the basis for lifelike animation in movies, initially and
notably A Swarm of Bats in the 1992 Tim Burton
film Batman Returns. In applications to real life, the ability

(06:13):
to understand the behavioral movements of large groups of starlings
or bats or bees or whatever, and to program swarms
of robots into making similar movements has amazing possibilities. This
is called biomimicry or biomimetics. An example, Las Cumbres Observatory
has 22 robotic telescopes on seven sites around the world

(06:33):
that coordinate with each other to function as one big telescope.
From the LCO website, It's called time-domain astronomy, which means
that we can continually watch phenomena in space as they change.
When we get to see the big picture as it unfolds,
we're able to learn more, learn it faster, and dramatically
increase our understanding of the forces that drive the universe.

(06:56):
Another example, the emerging field of swarm robotics uses information
gleaned from the study of starlings that could, according to
the Wyss Institute at Harvard, quote, enable new approaches for
search and rescue missions, construction efforts, environmental remediation, and medical applications.
Swarm robotics could also have use in military applications like

(07:16):
micro drones released from fighter aircraft. A swarm of self-driving
cars working together could help reduce or eliminate traffic jams,
all from watching, studying, learning, and building on the wondrous
flocking of this simple bird. Piesendorfer said, As humans who
have very complicated decision-making processes, we're not used to looking
at simple decision-making processes that scale up to what looks

(07:38):
like complex behavior. These models help us understand these types
of patterns. Today's episode is based on the article, The
Secrets and Science Behind Starling Murmurations, on HowStuffWorks.com, written by
John Donovan. BrainStep is a production of iHeart Podcasts in
partnership with HowStuffWorks.com and is produced by Tyler Klang. For

(08:01):
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