ZSL receives no state funding and relies on 'Fellows' and 'Friends' memberships, entrance fees, venue hire, and sponsorship to generate income.

[17] The zoo opened in April 1828 to fellows of the Society,[7] providing access to species such as Arabian oryx, greater kudus, orangutan and the now extinct quagga and thylacine.

[7][18] It was believed that tropical animals could not survive outside in London's cold weather, so they were all kept indoors until 1902, when Peter Chalmers Mitchell was appointed secretary of the Society.

Due to the public change of attitude to animals kept in captivity and unsuitably cramped space, the zoo also suffered dwindling visitor numbers.

Volunteers who give one day a week to assist the running of London Zoo, wearing red pullovers, are employed by both Education and Animal care.

Several of them are available for hire outside the zoo's opening hours, including The Terrace, Penguin Beach, Ninos cove, Tiny Giants, Land of the Lions, Tiger Territory, and Attenborough Komodo Dragon House.

[31] It covers 2,500 square metres, and is designed to resemble an Indian town on the edge of the Gir Forest National Park, intended to demonstrate how the lion's natural habitat overlaps with local urban environments.

Among the species in the main forest walk-through are Linnaeus's two-toed sloths, golden lion tamarins, red titi monkeys, red-faced spider monkeys, big hairy armadillos, Goeldi's marmosets, southern tamandua, golden-headed lion tamarins, red-footed tortoises and Rodrigues flying foxes.

The building also has a darkened area called "Nightlife", which houses nocturnal animals such as Mohol bushbaby, slender lorises, West African pottos, Malagasy giant rats, aye-ayes and blind cave fish.

The Mappin Terraces opened in 1913,[27] and features an artificial rocky cliff made of concrete blocks for animal enrichment.

The Mappin Terraces is currently an Australia-themed exhibit called "The Outback", housing emus, red kangaroos and red-necked wallabies.

[42][43] One of London Zoo's most well-known buildings, the Reptile House opened in 1927 and was designed by Joan Beauchamp Procter and Sir Edward Guy Dawber.

It is held in a building called The Millennium Conservation Centre, and the building displays over 160 species, including western honey bees, leafcutter ants, emperor scorpions, golden orb weavers, Madagascar orb weavers, Mexican redknee tarantulas, bird-eating spiders, desert locusts, moon jellyfish, partula snails and many others.

A single male northern rockhopper penguin named Ricky also lived there until he was moved to Whipsnade Zoo in March 2017.

[54] The exhibit is designed to resemble a shrub forest in Madagascar, featuring plant life such as loquat and Chusan palm trees.

[58] The Bird Safari opened in 2005 as a redevelopment of the old stork and ostrich house, replacing enclosures that were outdated by modern zoo-keeping standards.

The pavilion houses roughly 50 different species of exotic rainforest birds, including blue-crowned laughingthrushes, collared trogons, Socorro doves, red-crested turacos, splendid sunbirds and red-and-yellow barbets.

London Zoo established a Community Access Scheme in 2019 to provide 100,000 subsidised tickets to charities and groups assisting low-income families, older individuals, and people with disabilities.

[65] The scheme was successful and was later extended to allow anyone who received certain benefits to buy tickets for £3,[66] about a tenth of the full price, leading to visits by thousands of families, and long queues which were controlled by requiring pre-booking and capping numbers.

Old Martin was a large grizzly bear, the first in Britain, moved to the zoo with many other animals from the Royal Menagerie, Tower of London when it was closed in 1832.

[67][68] The zoo was home to the only living quagga ever to be photographed before the species became extinct in the wild due to hunting in southern Africa in about 1870.

Other now extinct species the zoo once held were the thylacine, the Falkland Islands Wolf, a pair of pink headed ducks, some Passenger pigeons, the Bubal hartebeest, the Syrian wild ass, the Northern Sumatran rhinoceros, the Javan tiger, the Schomburgk's deer, the Pinta Island tortoise, the Caspian tiger, the Glaucous macaw, as well as the endlings of the norfolk kaka, the Partula turgida snail, and the Santa Lucian Pilorie.

Jumbo became a crowd favourite due to his size, and would give rides to children on his back, including those of Queen Victoria.

[77] Her parents were killed by hunters, and she was flown from India to England, where she spent her adult life giving rides to the children.

[17] As the only giant panda in the West, she was the inspiration for Sir Peter Scott's design for the World Wildlife Fund logo.

Zoo staff later suggested that Chinese zookeepers knew that she was infertile and lent her in order to hide how much more advanced Western husbandry techniques were compared to theirs.

[86] The initial grounds were laid out in 1828 by Decimus Burton, the zoo's first official architect from 1826 to 1841, made famous for his work on the London Colosseum and Marble Arch.

[86] In 1830, the East Tunnel, which linked the north and south parts of the zoo together for the first time, was completed, which also acted as a bomb shelter during the Second World War.

After Burton, Sir Peter Chalmers Mitchell and John James Joass were appointed to design the Mappin Terraces.

[27] The Pavilion was commissioned "to display these massive animals in the most dramatic way" and designed to evoke a herd of elephants gathered around a watering hole.