By 2030, 60 percent of the world's population will live in cities, while one in three will share their city with at least half a million other inhabitants. With more and more people living in dense urban settings, what does the future hold for pets?
High-rise living might not be ideal for most pets, as outdoor access can be difficult and there may be limited space indoors. For cats in particular, a trend towards indoor lifestyles might restrict how much they're able to behave normally.
As the domesticated descendants of the African wild cat, cats are obligate carnivores – they need to have a meat-based diet. Naturally, this requires them to hunt. A study in the US found that pet cats could be killing up to four billion birds and up to 21 billion mammals every year.
So housebound cats may be good for wildlife, but how can people ensure their pets thrive indoors?
Sadly, scientific research is pretty light on this question. Despite so many of us inviting them into our homes, we know relatively little about how cats handle living inside.
Choosing the right cat
High energy and hyperactive cats, rescued strays with little indoor experience or those that aren't very friendly towards people aren't good choices for a life lived entirely indoors.
It's often assumed that older cats may be a better choice because they're more sedentary and cats with a previous history of living indoors may also adjust more easily to a new indoor home.
Some cats have diseases, such as feline immunodeficiency virus, that keep them housebound. But this doesn't mean these groups of cats will all have the right temperament to cope with indoor living.
Cat proofing gardens, for example, so they can't escape, could ensure pets can benefit from the outdoors in a more controlled way. But if this isn't possible, there's still much that can be done to improve a cat's life indoors.
Because cats are only considered semi-social, indoor environments may present several situations that they would usually choose to avoid. This can be anything from too much attention and unexpected guests to toddlers and other animals that don't understand the concept of mutual respect and personal space.
We know cats like boxes, but you can also give them high vantage points to climb to. To do this, you can use a "cat tree", although an accessible shelf or the top of a wardrobe would work well too.
Cats also need access to quiet rooms and spaces to hide under so they can remove themselves from situations they find stressful.
Be mindful though – if your cat spends most of its time hiding, your house may be less cat-friendly than you think. Uncontrolled stress in a cat's life can lead to illnesses such as idiopathic cystitis.
But what about their need to hunt? Allowing this behaviour is vital, and that includes them being able to look for food as well as finding and eating it.
Searching for food usually involves short bursts of activity and long periods of waiting in cats, while the feeding part is also complex, as the cat decides how and where is best to eat.
To recreate this, you can scatter food on the floor or hide it in puzzle feeders. You can even vary where you feed your cat and encourage it to explore and manipulate objects. Getting a cat to move more and eat regular, smaller amounts of food can help reduce the risk of obesity.
Play can also be used to mimic hunting without the need for food. It's always best to keep bouts of play short, encouraging pouncing and chasing, and using toys which mimic the shape, texture and movement of live prey.
You should always end on a positive note and while the cat is enjoying itself, so that future playtimes will be anticipated rather than endured.
Like humans, cats like to maintain themselves. Sharp claws are a must for effective climbing and defence, so make sure to provide scratching posts, especially if you want to protect your furniture.
In the wild, cats use trees and other objects, not just to maintain their claws but also to leave marks for other cats to follow.
Make sure your cat can comfortably go to the toilet. Use unscented litter that is changed regularly and put the toilet in a discreet place, away from their food and water.
For cats, as for us, it's not a public activity. If your cat is going to the toilet somewhere inappropriate, it may be that they're unhappy with their toilet arrangements or they may need to be checked by a vet.
Cats are as complex and each individual has unique needs. Before you decide whether to have an indoor cat, make sure that it's a decision the cat would be likely to make too.