Want proof that the world is getting wilder? Look no further than your own neighborhood. Animals that used to be found only in the wild are moving into human territory in increasing numbers, venturing into backyards and even city streets. There are 2,000 coyotes living in Chicago, mountain lions prowl the hills near the Hollywood sign, bears hibernate in Lake Tahoe basements, and in Dutch Harbor, Alaska, bald eagles dive-bomb post office patrons who get too close to their nesting grounds.

Internationally, it’s a similar story: cameras have captured kangaroos on an Australian golf course, pythons slithering through Bangkok, leopards on the streets of Mumbai and sloths (slowly) crossing the street in Rio. Simulcast on National Geographic Channel and Nat Geo Wild on Aug. 3, the three-part special “Urban Jungle” has the photographic evidence, and explains why it’s occurring more frequently.

Boone Smith, a wildlife biologist and big cat tracker by trade who hosts “Urban Jungle,” says it will help people “understand how these animals are so adaptive, take advantage of a new habitat, and live right under our noses without us even knowing about it. They know our habits, our routines, our noises, and all of these different things, and they've totally adapted to that and are functioning, doing what they do in this brand‑new, sometimes concrete environment.”

Kangaroos at a golf course in Australia

Kangaroos lounge around a golf course in Australia. (Photo: Corey Robinson/National Geographic Channels)

Why is this happening? “It’s about numbers,” Smith replies. “It’s just the reality of it. We’re sprawling across the landscape, populations have exploded, and there are very few un-roaded, untouched areas.” That’s why we hear about more close animal encounters than ever. “When a mountain lion attacks somebody it always makes the news and everyone goes on red alert,” notes Smith. “But the odds of this happening are small. You’re more likely to be struck by lightning twice than be attacked by a mountain lion. People need to use common sense around wild animals. If you see a bear and want to take a picture it’s not necessarily a bad intention, but a bear sees a big eye in its face and is going to react. It’s just reacting naturally and defensively.”

Smith was amazed to learn how well animals have adapted to urban environments, taking advantage of elements created by humans. “We didn’t build vacation homes in Tahoe with the intention of providing a good winter den. These are little niches they’ve found that they have been able to exploit because of their natural ability to change,” he points out. “In Dutch Harbor, there are few trees so the eagles nest in the cliffs near roadways we’ve created. These eagles compete for spots and defend them,” which means attacking people that they see as a threat.

In the video below, Smith investigates the bats that have made their home in the Congress Avenue Bridge in Austin, Texas.

He offers another example of the baboons that have overrun a border outpost between Zambia and Zimbabwe. “The baboons have figured out that people who come through there bring food and they’ve figured out how to get into cars and get free meals. They’re waiting for folks to come through and if it’s not strapped in, it’s gone. We learned that lesson the hard way. We had an open Land Rover filled with coolers and gear. And when we stopped to do our paperwork, those baboons were all over our vehicle. They emptied our cooler and stole some of our clothes. It all happened so fast.”

Smith was also startled to see kangaroos outside their usual Australian bush habitat, living on a Canberra golf course. “They come in because of the lush greens and a consistent water source, and they stay and reproduce,” he explains. “We saw the males competing for breeding rights, we saw breeding, territorial displays, the same behavior you’d see in the bush.”

Smith, who’ll be radio-collaring mountain lions in Wyoming and his native Idaho and lynx in Alaska in the coming months, hopes that viewers of “Urban Jungle” realize that animal encounters resulting in injury or death “are the anomalies. There’s a really cool wild world out there. And sometimes, we don’t have to be in wild places to see it.”

Related on MNN:

'Urban Jungle' explores why wild animals are invading our cities
Want proof that the world is getting wilder? Look no further than your own neighborhood.