Mountain Lions are found throughout the Santa Monica MountainsMountain Lions — Los Angeles, CA

Big cats mingle with the stars in Los Angeles. The Santa Monica Mountains, which transverse greater Los Angeles, are home to population of mountain lions that seem rather wild for LA's urban sprawl. The National Park Service monitors the movement and eating habits of more than 30 mountain lions with GPS collars in the Santa Monica Mountains. In 2012, one of the lions was filmed prowling through Griffith Park near downtown LA. That same mountain lion, known as P22, was also photographed by National Geographic photographer Steve Winter with the Hollywood sign in the background. While the LA mountain lion community is undeniably under threat because of habitat fragmentation, urban development, and low genetic diversity, two cubs were recently captured by motion-detecting cameras. Thankfully, they're described as "nice and fat."

Red Foxes number in the thousands in LondonFox — London, UK

In the last century, red foxes have colonized many urban areas throughout the United Kingdom. An estimated 33,000 urban foxes live throughout the country, with possibly 16 per square mile in London. While many Britons view the foxes as urban pests, others take to feeding their foxy friends. In 2011, one fox was found living on the top floor of the UK's tallest building, the Shard tower, while it was under construction. Described as a "resourceful little chap," he was captured and released back onto the streets of London.

Wild Boars wreak havoc on Berlin's parks

Boar — Berlin, Germany

Perhaps less cute but more menacing than the urban fox are the boars that roam Berlin's streets. In October 2012, four people were hurt when a 265-pound-boar attacked in the residential neighborhood of Charlottenburg. While boars are usually shy and remain out of sight, recent attacks on people and damage to municipal parks and gardens have led city officials to call for volunteer hunters to help cull the wild boar population of the city.

Sika Deer — Nara, Japan Sierra's Callum Beals and his deer friend

While spotting deer roaming through town isn't surprising to many of us, the Sika deer in Japan's Nara Park are particularly numerous. They are thought to be messengers of the gods and are closely tied to the Kasuga Shrine found in the park. Sika deer are also extremely friendly and regularly interact with humans, especially if you've got a snack for them to munch on.

Callum Beals is an editorial intern at Sierra. He recently graduated from UC Santa Cruz, where he studied history and literature. He enjoys hiking, camping, and waking up at ungodly hours to watch soccer games.

-- images by iStockphoto/Musat, visionsofmaine, kyslynskyy

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