A zoo (short for zoological garden; also called an animal park or menagerie) is a facility in which animals are held captive, displayed to the public, and in some cases bred, traded, loaned and sold.

The first zoos were created as private collections by the wealthy to show their power. These private collections were called “menageries”.

Wall carvings found in Egypt and Mesopotamia are evidence that rulers and aristocrats created menageries as early as 2500 BCE. They left records of expeditions to distant places to bring back exotic animals such as giraffes, elephants, bears, dolphins and birds. 

While zoos claim to provide conservation and education, their primary goal is to sustain public support in order to increase profits. As such, they focus on holding popular and charismatic species of animals captive.

Brown bear in German zoo. Image: Jo-Anne McCarthur / Born Free Foundation 

Urban and Suburban Zoos

Urban and suburban zoos, located in large cities, still resemble the smaller zoos that were popular 200 years ago. Often, these zoos sit in the middle of cities, making expansion difficult.

In many urban zoos, animals are kept in relatively small enclosures and are exposed to noise and pollution.

Antwerp Zoo is in the centre of Antwerp, Belgium, located next to the Antwerpen-Centraal railway station. Antwerp Zoo has over 7,000 animals in captivity on 29 acres.

Open Range Zoo

A number of open range zoos have been established since the early 1930s in rural surroundings. Fewer species of animals are exhibited in such zoos than in urban zoos, and they are kept in large paddocks. Animals are confined by a variety of methods including water-filled moats, dry moats, and wire-mesh fences.

Werribee Open Range Zoo, Australia

Roadside zoos

Roadside zoos dot the North American landscape. They’re generally small menageries where wild animals like lions, tigers, monkeys, wolves, and others are kept in captivity. The animals usually have less space and enrichment than traditional zoos, and there are often programs that encourage direct interaction with the animals (ie. photos, bottle-feeding cubs, etc).

Cherokee Bear Zoo – a roadside zoo in North Carolina – keep bears and other animals in desolate concrete pits or cages.


Aquariums are types of zoos that exclusively display aquatic animals in captivity.

Petting zoos

Petting zoos feature domesticated (often young) animals who are gentle enough for children to pet and feed. Sheep, goats, donkeys and rabbits are common animals used in petting zoos.

Read more in our separate section on Petting Zoos

Marine Parks

Marine Parks hold large aquatic animals in captivity, often training them to perform to entertain humans. 

Head to our Marine Parks section to learn more.


Unsurprisingly, scientists are beginning to observe the psychological impact that this sort of confinement is having on zoo animals and the results aren’t good. The term “zoochosis” was coined by Bill Travers in 1992 to characterise the obsessive, repetitive behaviors exhibited by animals kept in captivity.

The behaviors displayed by animals in zoos range from pacing, to rocking and swaying, all the way through to aggressive self-directed behavior like self-mutilation, over-grooming, and vomiting.

It is not unusual to see jungles, deserts or icebergs painted onto the walls of enclosures that hold wild animals. These attempts to make the enclosures look natural are for the benefit of the public only – the animals are not fooled, they know they are not in the wild.

Tigers and lions have around 18,000 times less space in zoos than they would in the wild. Polar bears have one million times less space.

A tiger in a zoo in Denmark. Image: Jo-Anne McArthur / Born Free Foundation

It’s common to see tigers and lions pacing up and down, over and over again, at the window of their enclosure, or elephants swaying their heads from side to side as they stand rooted to the spot. These behaviours are a sign of mental distress, brought on by captivity.

The documentary film Zoochosis digs into the underlying causes of these abnormal, seemingly mindless behaviors. 

To counter these problems, zoos internationally have been known to give drugs to affected animals. In her book, Animal Madness, Laurel Braitman says that the practice of putting animals on antidepressants is surprisingly common.

One case Braitman shares is of a polar bear named Gus who lived at Central Park Zoo. Gus began compulsively swimming figure eights in his pool for up to 12 hours per day.

An animal psychologist determined that Gus was bored. And not surprisingly, given that his enclosure was less than 0.00009% of what his range in the Arctic would be.

Rather than acknowledging that a life in captivity could never provide Gus with the enrichment he required, he was given behavioural therapy and a prescription of Prozac. Gus died in captivity in 2013 at age of 27.

Gus peers through the glass wall of his enclosure
Photo: Johnia/Flickr

Zoos kill healthy animals

Healthy animals in zoos are intentionally killed when they are no longer wanted. 

Lions at Longleat Safari Park were killed after the zoo let inbreeding get out of control. 

Marius the giraffe was killed, publicly dissected and fed to the lions at Copenhagen Zoo, after the zoo said he was unsuitable for breeding. 

In response to widespread criticism, Copenhagen Zoo’s Scientific Director defended the decision, saying that the zoo had a “surplus” of giraffes with a similar genetic make-up, and their commitment is to the overall breeding of the species, not an individual’s wellbeing. Just a short time later, Copenhagen Zoo was in the news again for killing four healthy lions to make room for a new male lion they wanted to breed. 

Training animals to perform

Many zoos train animals to perform tricks as if they were in a circus. Performing big cats, birds and elephants can be seen at many zoos.

Buying, selling and trading animals

Zoos and aquariums, exhibiting a wide variety of animals, are often involved in international movements of and trade in wild and captive-bred animals. 

Zoos have declared thousands of lions, tigers, bears and other creatures “surplus” because of over-breeding, inadequate funding or simply because the animals failed to wow visitors as they once did. Some zoos have sold the animals to brokers, who funnel them to breeders, hunting ranches, research facilities, circuses, auctions or individuals looking for exotic pets.

Image: Jo-Anne McArthur / We Animals

“But zoos are important for conservation!”

Whilst some zoos may contribute in small ways to conservation projects, the vast majority of animals in zoos are not on the endangered species list, and the ones who are will likely never be rehabilitated to their natural habitat. A study conducted by Captive Animal Protection Society (CAPS) found that more than half of the animals in breeding programs in the EU were not endangered in the wild.

Ultimately ‘captivity for conservation’ is not an ethically acceptable reason to imprison animals.

We now have unlimited options for entertainment, not to mention a greater understanding of animal sentience and needs. In today’s society, looking at animals in zoos behind glass is outdated and completely unnecessary.
In 2013, Costa Rica declared that it would be closing the country’s two public zoos, citing concerns about animal captivity and welfare. More than 400 animals residing in the zoos were transferred to private animal-rescue centres around the country, and those that were able were rehabilitated and released back into the wild.


Ready to boycott zoos? There are an array of other ethical options to learn about, observe and connect with animals.

Visit a sanctuary

There are many sanctuaries that provide lifetime care for rescued, abused, unwanted or discarded animals. There are numerous farmed animal, equine and wildlife sanctuaries all over the world, and many have open days.

It’s important to note that there are zoos and wildlife exhibits that call themselves sanctuaries, but they are not, and as such each facility should be looked into on their individual merits prior to visiting.

The Sheldrick Wildlife Trust in Kenya is one of Africa’s oldest wildlife charities and a leading conservation organisation.
A volunteer feeds a pelican in rehabilitation at the Pelican Harbor Seabird Station in Florida, Miami

Visit or volunteer at a wildlife rescue or rehabilitation centre

A wildlife rescue or rehabilitation centre is a temporary home for sick, injured or orphaned animals, either domestic or wild.

Offer your land as a wildlife release site

If you or your family have a large, natural property, consider partnering with a wildlife rehabilitation centre and becoming a release site for animals. You can be the starting point for any number of wild animals going back into the wild.

Warriors 4 Wildlife releasing a rehabilitated eagle

Travel to observe animals in their natural habitats

Take a trip in your own state, or explore another, to observe wildlife in their natural habitats.

Most countries offer their own unique brand of ecotourism. Ecotourism benefits wildlife by helping fund local conservation projects, but drawbacks exist, including increased incidents of human-wildlife interactions. Keep in mind to be respectful of the animals, the ecology, and the people of the communities you visit.

Make sure to investigate the legitimacy of facilities before you visit. Breeding animals, hoarding them, riding them, making them perform, or profiting from them in any way should raise red flags.

Check out this list of 10 amazing places to see animals in the wild.