Urban wildlife on the rise

Peregrine falcons nesting in downtown Phoenix a part of a growing trend of animals adapting to, living in our expanding cities

screenshot of peregrine falcon in Downtown Phoenix box


Downtown Phoenix’s newest high-rise residents don’t take the elevator when they come home.

A pair of peregrine falcons has made a home in a nesting box atop the Maricopa County Administration Building, becoming Internet stars (thanks to a webcam), capturing the public imagination and terrorizing the pigeon population.

The feathered bullets are part of a growing trend of urban wildlife throughout the world that includes coyotes in Manhattan (and Phoenix, and Los Angeles, and ...), wild boar in Berlin, leopards in Mumbai and Nairobi, and foxes in London. More coyotes live in Tucson than in adjacent wilderness areas.

There are field guides to urban wildlife for sale on Amazon, academic conferences, and advocacy groups. The U.S. Fish and Wildlife Service’s National Wildlife Refuge System boasts 101 urban wildlife refuges around the country.

“It’s a very robust part of nature,” said Randy Babb, wildlife viewing program coordinator with the Arizona Game and Fish Department.

Whole generations of animals now have lived only in urban areas, Babb said.

“Things like coyotes and javelina, like that — we now have animals that are living within the confines of the urban area,” he said. “Those animals live their whole lives there. They’re living in culverts and flood-control structures. They feed on people’s pets, things people leave out, gardens. There is a very significant urban wildlife situation here in Arizona.”

A coyote.

More coyotes live in Tucson than in adjacent wilderness areas, according to Randy Babb of Arizona Game and Fish.

Photo by Christopher Bruno/ Freeimages.com

Pierre Deviche, ornithologist and professor in Arizona State University’s School of Life SciencesThe School of Life Sciences is an academic unit of the College of Liberal Arts and Sciences., went to an urban wildlife conference last year in Chicago attended by 200 researchers.

“You have more and more people living in cities, and cities are becoming enormous,” Deviche said. “I think more and more people are becoming exposed to wildlife living in cities, and you’ve got to deal with it.”

David Pearson, ornithologist and research professorPearson is also a senior sustainability scientist in the Julie Ann Wrigley Global Institute of Sustainability. in ASU's School of Life Sciences, said as humans invade more and more of the world, a lot of organisms beside cockroaches and rats are evolving to co-exist with us.

“It’s a nice way to look at the future,” said Pearson, who has a grey fox living on his roof in Tempe. “As we approach 12 billion people in the world, there are going to be a lot of changes.

“Sadly many organisms will go extinct, but a few organisms you wouldn’t expect are going to be able to adapt and evolve and live side by side with us. There are coyotes in downtown Los Angeles, downtown Chicago. They are super well-adapted for being sneaky and adapting and in some ways maybe benefiting us by the things they’re going after, like rats. The world is going to be very different.”

He cited the Eastern coyote, which has evolved in the past few decades into almost another species. Some of its genes are dog and wolf. It’s much larger than its Western counterpart, hunts in packs and doesn’t have much fear of humans. The big question is what species will thrive and what won’t, Pearson said.

“You can’t expect the organisms to just sit back and adapt to whatever we do to them,” he said.

There are falcon cams in Boise, Idaho; Buffalo, New York; Columbus, Ohio; seven in Minnesota; and nine in Chicago and its suburbs. The peregrine is the official city bird of Chicago. In cooperation with Maricopa County, Game and Fish was able to install a camera to monitor the birds nesting on top of the downtown Phoenix building, which is at Third Avenue and Jefferson Street.

Peregrine falcons have actually been nesting in downtown Phoenix — the Maricopa County Administration Building in particular — for more than a decade, according to Babb.

“(The webcam) is the most popular spot on our website right now,” he said.

A screenshot from a webcam of a peregrine falcon.

The male of the pair of peregrine falcons is shown in a screenshot from the Arizona Game and Fish Department’s webcam. The male is about one-third smaller and has whiter chest plumage compared with the tawny breast of the female (seen in the top photo).

The term “falcon” refers to a female. The male is called a tiercel, which comes from a German word for “one-third,” because the male is one-third smaller than the female. Peregrines have very large feet in comparison to the rest of their body, which helps them to capture and hold prey in mid-flight.

They dive at about 200 miles per hour. They are the fastest animal on Earth and have been recorded diving at up to 242 miles per hour. F-16 pilots have reported the birds passing them in dives. They hit prey in mid-air, usually killing it instantly.

Peregrines mostly eat pigeons. “It’s an easy source of food for them,” Deviche said.

The female is in the downtown Phoenix box much more than the male. When the male shows up — sometimes with prey, sometimes not — he flattens his wings against the bottom of the box and they knock beaks together and keen at each other.

“I can’t honestly say I speak peregrine,” Babb said. “They do a variety of different bonding and courtship behaviors. You’ll see them call to teach other. They’ll fly in and do beak-clacking when they knock their beaks together. Most of that stuff is just bonding behaviors. ... Most of these things are pretty well documented in literature, but you never get to see it.”

Being able to watch the birds is rare and a huge draw even for people who normally wouldn’t look away from their phones.

 “It’s a very charismatic species, and even non-bird-watchers and people who otherwise wouldn’t have a second glance at the wildlife around them find them very interesting,” Pearson said.

“I think it’s something people really appreciate,” Deviche said. “You can be at home and see these birds right there.”

“As we approach 12 billion people in the world, there are going to be a lot of changes. ... There are coyotes in downtown Los Angeles, downtown Chicago. They are super well-adapted for being sneaky and adapting and in some ways maybe benefiting us by the things they’re going after, like rats. The world is going to be very different.”
— ASU research professor David Pearson

Peregrine falcons have been living in cities for a while. Until the pesticide DDT was banned in 1970s, many bird populations crashed. (The chemical made eggshells perilously thin.)

“The bald eagles, a whole bunch of birds’ populations were crashing,” Deviche said. “After that, they rebounded. People have been seeing them much more, and they’re becoming much more common. They used to be really rare.”

Deviche has seen them on the Tempe campus occasionally, sometimes on top of the Biodesign building. Pearson said some used to nest atop the roof of (appropriately enough) Life Sciences Tower E-Wing. Peregrines like high places. Why did this particular pair choose the box on the county admin building?

“You would have to ask the bird,” Deviche said. “Traditionally these falcons nest on cliffs. High-rises, big buildings in cities are surrogates.”

Peregrines aren’t the only winter visitors. Cooper’s hawks spend the winter here in town. Red-tailed hawks are common along the Salt River. American kestrels like Phoenix, too.

“We’ve got multiple birds of prey around here,” Deviche said. “Phoenix is a good place for these birds. We’ve got lots of parks and green spaces. They can find food and things like that pretty easily.”

It’s a mystery why some species do well in urban settings and others don’t, Pearson said. 

“Why do some birds — native desert birds — do so well in urban situations?” he said. “It’s really hard to figure out what it is that all these birds have in common. Cactus wren, Abert’s towhee, the curve-billed thrasher — why do they all do so well in urban situations?”

Cactus wren do very well in the Valley, but not at all in San Diego, he said. No one knows why.

Meanwhile, thousands of Phoenicians keep checking in online to see whether the downtown falcons produce young in their new home.

If the birds raise a family in there, “you can see them getting bigger and bigger, and one day flying away,” Deviche said. “That is what we can hope for.”

Top image: The female of the pair of peregrine falcons nesting in the Maricopa County Administration Building in downtown Phoenix, shown in a screenshot from the Arizona Game and Fish webcam, which can be viewed here.

More Environment and sustainability


People on a boat.

Assessing the red alert on corals

As our planet continues to warm, rising ocean temperatures threaten coral reefs across the globe. But not all corals are created equal, and some may be able to withstand higher temperatures or longer…

A collection of maroon, yellow and light blue coral on a flat ASU gold background

Designing a more sustainable future with AI

Editor's note: This feature article is part of our “AI is everywhere ... now what?” special project exploring the potential (and potential pitfalls) of artificial intelligence in our lives. Explore…

Greenery superimposed with icons representing environmental data points.

ASU researchers incorporate data into decision-making for conservation efforts

Leah Gerber sees conservation as a crisis discipline — the work involved tends to be reactive, with the engaged decision-makers rapidly basing their guidance on the available information.“When you go…