Ealing beavers swimming
Watch: Wild beavers return to west London's wetlands for the first time in 400 years
03:37 - Source: CNN

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CNN  — 

More than half of the world’s population live in urban areas where nature can feel like a distant concern.

Thriving ecosystems do, however, exist within our cities — even beneath our feet — and embracing urban nature can be a powerful force for change.

For example, West London has its first beaver dam in 400 years after the reintroduction of a family of five in October to a wetland on the city’s outskirts. The industrious beavers could help to prevent flooding after heavy rainfall.

Our Shared Home was the theme this week for CNN’s third annual Call to Earth Day, during which the network highlighted the crucial connection between cities and wilderness.

Once upon a planet

Chacma baboons overlook Cape Town, South Africa, from a hillside.

Interactions between urban dwellers and wildlife don’t always run smoothly.

Cape Town’s baboons can often be found rummaging through garbage cans and around backyards, putting them at greater risk of conflict with humans.

For the primates, the raiding behavior makes some sense — the suburbs encroach on their feeding grounds. Easy access to food from Cape Town’s trash means baboons spend less time and energy foraging, and more on socializing with potential mates and the rest of their group.

However, there are consequences for the baboons. Their health and welfare can suffer as the primates come into contact with dogs, cars and electric power lines. Some baboons have even been shot.

The city has begun taking proactive measures to keep them away from Cape Town’s outskirts and in their natural hillside habitat.

Fantastic creatures

Much nature photography focuses on the wild wonders of Earth and its majestic biodiversity.

Two photographers whose works CNN profiled as part of the Call to Earth initiative took a different approach. They captured intimate views of wildlife in an urban habitat.

Photographer Corey Arnold discovered a bear denning in a California home’s crawl space, while in the lush hillsides of Hong Kong’s New Territories, Lawrence Hylton recorded a collared scops owl, a white-lipped pit viper and an Atlas moth during his nocturnal safaris through Shing Mun Country Park.

The stunning, and sometimes amusing, images show how smart some animals are at adapting to a human-dominated landscape.

Look up

An image of the rare Steve phenomenon captured by Canadian photographer Neil Zeller.

The sun is entering a period of heightened activity, making it easier to witness dazzling natural displays like the northern lights or their counterpart in the Southern Hemisphere.

There have also been sightings of an even rarer night-sky phenomenon that occasionally accompanies auroras. Known as Steve, it appears closer to the equator than polar auroras and is characterized by a purple-pink arch and green vertical stripes.

The mysterious light show was formally identified less than a decade ago, and explanations of what causes it are still taking shape.

The phenomenon’s name also has an unusual origin story involving a 2006 DreamWorks movie.

Across the universe

Astronomers have discovered six planets around a nearby sunlike star with orbits that haven’t changed for more than 1 billion years.

Larger than Earth but smaller than Neptune, the exoplanets are in a little-understood class called sub-Neptunes commonly found in the Milky Way.

As the planets revolve around their host star, which is about 100 light-years away from Earth, they display a pattern known as orbital resonance. This is when the planets complete their orbits and exert gravitational forces on one another, creating a harmonic rhythm, with all six planets aligning every few orbits.

Scientists believe the discovery could help unravel mysteries of planet formation.