To find out how to act when you meet some of the most common animal wanderers, we contacted the UK's leading veterinary charity, The People's Dispensary for Sick Animals or PDSA.
"If you find a healthy-looking dog without an owner in the UK, it is likely to be lost rather than a stray," PDSA vet Claire Roberts told Bored Panda.
"Legally, all dogs should be wearing a collar with their owner's name and address on the tag. If it is safe to approach the dog then you can check to see if you are able to contact the owner. Scared dogs may lash out so keep an eye on their body language and don’t approach them if you have any concerns."
Roberts explained that dogs and puppies over eight weeks old are required to be microchipped by law in England, Scotland, and Wales, so if you are able to, contact the local vets who should be able to scan for a microchip. This holds true in many other places too. "If you are not able to transport the dog to the vets, feel uncomfortable approaching them, or if the dog is not microchipped then you will need to report the dog to your local council," Roberts added.
On the other hand, the vet highlighted that it can be hard to be sure if a cat is a stray as many of them roam freely in their neighborhood. "If you spot a cat you think is a stray, you can ask around your neighbors or on social media to see if it belongs to anyone - you might be surprised as some cats have several families that they visit regularly! You can also print out a paper collar with your contact details on it, asking the owner to contact you."
"Cats are not currently legally required to have a microchip, but your local vets may be able to scan the cat to check. As with dogs, only approach the cat if they seem friendly and you are comfortable doing so," Roberts said.
It's important to remember, however, that some critters are less fortunate than others. "If a stray cat or dog is injured or ill, then the best thing to do is call your local vets to discuss how they can help," Roberts said.
"Most vets will be able to provide initial help if you are able to get the animal to them, especially if they are sick or injured."
The PDSA vet advises being gentle when handling these animals as they may be in pain or unused to human contact. "If you're not sure how best to help, or you do not think that you would be able to transport them, you may need to call an organization who looks after injured strays, such as the RSPCA or Cats Protection," she said.
Running into some of these animals might seem impossible, but when you think about it, there's a pretty good chance you'll be able to take a similar picture at some point in your life.
For example, in downtown Chicago, a coyote can easily make a den in a cemetery—as insane as it sounds, there are up to 4,000 of them living in the area.
And in Los Angeles, a mountain lion can roam the Hollywood Hills, tiptoeing around throngs of tourists without ever being seen.
As people flock to cities like never before—six billion are expected to live in urban areas by 2045—they're not alone.
Attracted to plentiful food and mostly protected from hunting, among other natural dangers, a colorful variety of creatures are also moving into cities.
Several species have adapted to living in much tighter urban spaces than they do in the country. Some have become active at night when people aren’t around, and perhaps most crucially, many have figured out how to navigate busy roads without getting hit by a vehicle.
"We forget that we are the biggest cause of evolution on the planet right now,” Suzanne MacDonald, a psychologist and biologist at York University in Toronto, Canada, who studies urban raccoons, told Nat Geo.
"We have this view of the wild as a pristine place" and of evolution as something that happens "in the wild," she said. "But humans in cities are changing the animals now."
And with so many animals going urban, humans must view cities as part of—not separate from—nature, adds MacDonald.
"To live in harmony with animals whose habitat we’re destroying, we’re going to have to do a lot more work in what we’re doing to them."
Intrigued by the innovativeness some of the species display, urban ecologists are studying whether city animals are craftier than their rural counterparts at tackling challenges.
The Barbados bullfinch, for instance, sure seems to be. The island native has made a name for itself by stealing sugar packets from restaurant terraces.