More than half of people around the world live in cities, with an estimated 70 per cent projected to live in urban areas by 2050. In Los Angeles, the inhabitants also include creatures such as mule deer, bobcats, coyotes and even the occasional black bear. So humans have had to learn how to share their space with this diverse group of animals.

But in 2012, local wildlife biologist Miguel Ordeñana was surprised by the footage recorded at one of the camera traps he'd set in Griffith Park. The sound of crunching leaves was followed by a tan shape moving across the screen.

The park's newest resident — the mountain lion featured in this clip from the "Cities" episode of The Nature of Things series Shared Planet — had travelled a long way to get there.

To reach Griffith Park, the mountain lion, or cougar, named P-22 had to traverse dangerous highways and heavily populated areas of the city, a journey that's killed other big cats. As a result, P-22 was boxed in by freeways and surrounded by humans on the smallest-known territory occupied by a mountain lion — 17 square kilometres.

Being a nocturnal hunter, P-22's nightly activities, captured by camera traps and on home-security videos, consisted of devouring prey, performing a song composed of screechy chirps, and a leisurely neighbourhood stroll.

People around the world were so inspired by the "Hollywood Cat," that about $50 million was donated to build the world's largest wildlife overpass. The bridge will allow wildlife in the Santa Monica Mountains and the Sierra Madre Range to safely cross a 10-lane highway on the outskirts of L.A. P-22 even had a festival established in its name — the annual P-22 Day Festival in October.

However, after 10 years of P-22 peacefully coexisting in Griffith Park, wildlife experts had to make a difficult decision.

Watch the video above for the full story.

Watch Shared Planet on CBC Gem and the Nature of Things YouTube channel.