As cities grow and populations rise, urban wildlife adapt and change to live alongside 21st century humans.

Often, this means changes in diet or behaviour, but there are also new, sometimes surprising species making it in the cities.

As the Planet Earth II: Cities episode showed, while there certainly are challenges, some species thrive in our growing urban environments.

Red kites in the UK

It is quite something to see a bird of prey with a wingspan of almost 2m hovering above supermarkets, wheeling above shopping malls and hunting between high rise flats. Following a successful reintroduction scheme, the red kite has firmly established itself in towns in many parts of England and Scotland. With a diet of carrion, motorways and big roads are full of roadkill to make a potential meal. ‘Commuter kites’ have been spotted swooping into the town of Reading where people controversially put scraps out in their gardens. As with any animal that succeeds where people live, some consider the birds a pest. A study published last year suggested that poisoning of kites could be slowing their rate of recovery. In fact, kite were common in cities in medieval times and Shakespeare called London the "city of kite and crow" before they were exterminated for a few hundred years.

‘Commuter kites’ have been spotted swooping into the town of Reading where people controversially put scraps out in their gardens (Credit: Christian Talarek)

Wild boar in Berlin

With their hefty trunks, sharp tusks and adorable striped piglets, wild boars are easy to spot. If you were standing in central Berlin’s Alexanderplatz shopping square, they would be very hard to miss. Wild boars are thriving in the Germany city and have even been spotted roaming through the busiest areas of the metropolis. The population is currently estimated at 3,000 and there are three isolated populations in forests of the capital. Road accidents, a herd stopping a suburban train and reported incidents with dogs and humans has led to the environmental group NABU receiving calls every day about the wild swine. One person is licensed to cull the pigs in the city, but with restrictions on hunting and no natural predators, the wild boars are here to stay.

Berlin's wild boars are here to stay (Credit: NABU Berlin/Wolfgang Stürzbecher

Yellow-crested cockatoos in Hong Kong

The yellow-crested cockatoo, an all-white bird but for its lemon yellow crest, is on the IUCN’s Critically Endangered list. It has been hunted and sold due to international demand as a pet, and affected by pesticides, lack of food and high rainfall. In heavily urbanised Hong Kong, however, a feral population has established itself. The estimated number of birds is 200, which is 10 per cent of the global population. “This is a key example of how Hong Kong - a heavily urbanized city-state - can play a role in the conservation of globally threatened species,” said co-author Mr. Yong Ding Li, a PhD student at the Australian National University.

Yellow-crested cockatoos have found sanctury in Hong Kong (Credit: Peter & Michelle Wong)

Coyotes in the United States

The sound of howling coyotes is no longer a surprising occurence for some New Yorkers. The native canine has adapted to urban living in the East of North America, filling the ecological niche left by the demise of wolves. A photograph of a coyote on a rooftop in Queens, New York, went viral in 2015, and others have been found in abandoned buildings and parking lots. Another, named Hal, was found wandering around Central Park. Coyotes mainly eat wild prey - rabbits and mice - but will also feed on leftovers and scavenged meals. Populations have colonised metropolitan areas across the States, from Chicago to Los Angeles and Boston to Austin, Texas.

Populations of Coyotes have colonised metropolitan areas across the States, from Chicago to Los Angeles and Boston to Austin, Texas (Credit: northohana)

Leopards of Mumbai

An estimated 35 to 41 leopards live in the Sanjay Gandhi National Park, on the outskirts of Mumbai. Photographs of the beautiful animals against the backdrop of the bright lights of India’s most populated city are jaw-dropping but belie ? current leopard-human tensions. As much as people complain about foxes and raccoons in their urban backyards in other areas of the world, leopards can actually attack and cause fatal injuries to humans. As leopard habitats shrink and they move into the cities to survive, some communities are afraid to leave their houses. Children in affected areas must walk around in groups of six or more. However, a recent study suggested that the leopards may be protecting their human neighbours from rabies. Around 40 per cent of the leopards’ diet is feral dogs, which is the main source of the deadly virus.

Mumbai is home to the highest concentration of leopards anywhere in the world. They capitalise on hunting the animals that man brings into the city. (Credit: BBC 2016)

By Lucy Jones

Featured image by BBC 2016