[warm intro music] (narrator) In big cities across America, a surprising new resident has moved in.

[soft suspenseful music] Let's see, there's a good chance that hopefully he'll take off and go south to where he normally is at.

(narrator) A wild hunter lurking in shadow.

He was right here.

I think we just pushed him around.

The core of his territory is further south.

We're getting close to the edge up here.

Oh, oh, there he is.

(narrator) What are wild coyotes doing in a city as dense as Chicago, and how is their presence here changing our ideas about how the human world and natural world can coexist?

[soft suspenseful music continues] As humanity's footprint relentlessly expands across the globe, The space available to our animal neighbors shrinks.

More than half of the world's habitable land is taken up by agriculture and urbanization.

This pressure is forcing many wild creatures to adapt or die.

Few species have adjusted as well to this new world as coyotes.

The Chicago metropolitan area is the third largest in the US, home to 9.5 million people.

In spite of its human density, the Chicago coyote population has grown steadily over the past few decades and now numbers close to 4,000.

[upbeat percussive music] You'll even find them stalking among downtown skyscrapers.

(speaker) The concerns rose to the level where we were asked to develop a project to actually investigate.

That project started in the 1990s when coyotes began appearing in parts of the Chicago area that they'd never been seen before.

There wasn't much known about coyotes living in urban areas, because it hadn't really been documented much.

(narrator) To figure out why so many of these creatures are here, researchers from Chicago's Urban Coyote Research Project are using tracking collars.

They've collared more than 600 animals... -[camera snapping] -over 20 years.

The collars allow scientists to track the animals' movements across the city and study the coyotes' behavior.

[light playful music] (Stanley) When we started, we had a lot of preconceived notions.

And in most cases, we were dead wrong.

We assumed that any coyotes that are appearing in these areas of Chicago were only there temporarily, just moving through.

(narrator) But one of their first discoveries was that coyotes were taking up permanent residence inside the city.

(Stanley) They are extremely territorial.

They spend a lot of their time patrolling their boundary and to maintain these highly structured territories.

Overlaid on that patchwork of territories, you have solitary coyotes that have left their family groups just simply floating around looking for vacant territory.

(narrator) The coyote population in Chicago has grown so large that these drifters have sought refuge in the only habitat available to them: downtown.

[soft suspenseful music] And it's not just Chicago.

This resourceful canid has spread into other major cities, including Los Angeles, San Francisco, and even New York.

(Stanley) The narrative that the general public typically sees is that coyotes conflict with us, because that's the only way they make the news.

People just don't understand that they have to avoid us to survive in a city and they have to be really good at it.

(narrator) They've become urban ghosts hiding in our midst.

(Stanley) The first thing we noticed is that they become much more nocturnal in their activity patterns.

The other thing that we notice is that they learn how to cross the roads very well.

(narrator) Some have actually been observed using traffic lights to safely cross streets.

And another reason they're able to avoid us is that, despite living among us, they don't need our help to live here.

(Stanley) And we have thought, "Well, if they are existing there at all, "it's only through our help, mainly through us feeding them."

We were really shocked they could continue to find their natural prey and function like a predator, even in some of the most developed areas.

[soft suspenseful music continues] [soft suspenseful music] (narrator) Coyotes are the largest mammalian predator in North America that's able to survive in cities and still maintain its wild lifestyle.

But it's not the only species that makes up Chicago's urban ecosystem.

In fact, in places like this, conservationists are starting to rethink the relationship between cities and wildlife.

(speaker) The prevailing narrative of conservation casts cities as the villains: they leave nothing behind, it's just this gray concrete wasteland.

There is some truth to that, but at the same time, the reality is so much more complex.

There are these amazing interactions happening all around you.

(narrator) Magle's team has spent the past 12 years documenting this with camera traps, capturing images of coyotes and other urban wildlife throughout the greater Chicago area.

(Seth) It's the largest urban wildlife study that's ever been conducted.

We really are trying to understand the entirety of this urban wildlife system.

If we understand how animals make decisions in how to select habitat, we can tweak that environment, we can engineer the wildlife communities that we want.

(narrator) Seth and other researchers dream of designing a more wildlife-friendly Chicago and hope to inspire other cities to do the same.

(Nick) You can create ecosystems within cities that support populations that previously had lived there.

(narrator) One place that's happening is the industrial Chicago River.

A section of it is now called the Wild Mile.

(Nick) We're emulating the natural conditions of a regular river within an urbanized ecosystem.

So we take that existing infrastructure, steel channelized walls, and we transform it into something that is more amenable to the wildlife.

The floating gardens essentially mimic the naturalized edge conditions of a regular river.

Native plants grow on top of 'em, and their roots grow directly through these and hang underneath the water into the river.

And they create fish habitat, they create bird habitat, insect habitat, and really jumpstart the ecosystem within the river.

And we really try to experiment and create an environment that works the best.

Probably the most surprising thing was seeing a coyote on a dock in the Chicago River.

There's something providing for them there, and that, to me, is a good sign.

(narrator) Cities like Chicago are teaching us that humans can coexist alongside wild species in ways that we never imagined possible, and that urban environments can be built for the benefit of people and nature.

(Stanley) If we can continue the research on understanding their ecological role, we'll probably find that we're actually benefiting from coyotes to a much greater extent than what we currently understand.

(Seth) We live on a planet that's becoming more and more urban every year.

Human populations are increasing, and more and more people are living in cities.

If we want to have wildlife on that planet, we need to understand how do we make those cities places where people and wildlife can thrive together?

[soft bright music] Accessibility provided by the U.S. Department of Education.

[soft bright music continues] [soft bright music flourishes] [bright percussive music]