Are zoos and aquariums good for conservation?

The objection

“Zoos and aquariums protect endangered species, run breeding programmes and teach the public to care about wildlife. Without them, conservation would be far worse off.”

The answer

Captive breeding has pulled a few species back from the edge. The last wild Arabian oryx is believed to have been shot in 1972, and captive breeding and reintroduction had about 1,000 back in the wild by 2011, when the IUCN moved the species from Endangered to Vulnerable [1]. Only 23 California condors survived in 1982; every wild one had been taken into captive breeding by 1987, and the US Fish and Wildlife Service and partners including the San Diego and Los Angeles zoos have since grown the population to more than 500, wild and captive [2]. Captive breeding played a major role for 13 of the 68 species whose IUCN Red List status had improved, and most recoveries through captive breeding have started from fewer than 30 animals (Conde et al., 2013) [3]. In a survey by their own world association, zoos and aquariums reported spending about US$350 million a year on wildlife conservation (Gusset & Dick, 2011) [4].

The part of this that can be defended is breeding genuinely threatened species so that they can go back to the wild, as with the oryx and the condor. Most of what a zoo ticket pays for is something else. The studies below find that most of the animals on show belong to species that are not threatened, that collections do not reliably change when a species’ conservation needs do, and that a visit adds only a little to what people know, while the orcas’ teeth show what life in a tank does to an animal’s body.

Are most zoo animals endangered?

Most animals in zoos and aquariums belong to species that are not threatened with extinction. In 2011 fewer than a quarter of the 3,955 land vertebrate species in the 837 zoos sharing records through the International Species Information System were threatened, and in 57 of 59 orders of animals the share was no higher than picking species at random would give (Conde et al., 2013) [3]. In the UK, the 113 zoos and aquariums that make up 92% of the British and Irish Association of Zoos and Aquariums listed 106,240 vertebrates in 2023 and 2024, and under three in ten belonged to globally threatened species (Lennon et al., 2026) [5].

Do zoos choose their animals for conservation?

Zoos do not consistently change what they keep when a species’ conservation needs change, according to the first global study of the question. Jenkins et al. (2026) followed the holdings of 7,240 species of amphibians, reptiles, birds and mammals across 613 zoos and similar institutions from 1990 to 2021: species moved to a higher level of conservation concern did not consistently gain holders, and species moved down were rarely phased out [6]. Managed breeding programmes were the factor most strongly linked to gaining holders, though they often included species kept for reasons other than conservation [6]. The UK study’s authors suggest one pressure behind this: visitor income is most zoos’ main source of revenue, which may push collections towards large, charismatic species that draw a crowd [5].

Do zoo visits teach people to protect wildlife?

Zoo visits teach a little, according to a survey of 5,661 visitors at 26 zoos and aquariums in 19 countries (Moss et al., 2015) [7]. Its authors, from Chester Zoo, the University of Warwick and the zoos’ own world association, called it the largest and most international study of zoo and aquarium visitors to date [7]. Zoos and aquariums draw more than 700 million visits a year, and among the people surveyed the share showing at least some understanding of biodiversity rose from 69.8% before the visit to 75.1% after it, and the share able to name something they could do to protect it from 50.5% to 58.8% [7]. The study measured what visitors knew as they left, not what they went on to do.

What does captivity do to orcas’ teeth?

A 2017 study of 29 captive orcas found dental damage in every whale, beginning at a young age (Jett et al., 2017) [8]. Scoring dental images of whales owned by one US theme park company, Jett and colleagues found major to extreme wear on the lower teeth of about a quarter of them; more than 60% of the second and third lower teeth were fractured, and more than 61% had bore holes from drilling [8]. They found that oral stereotypies contributed to the damage [8]. National Geographic (2019) describes stereotypies as repetitive behaviours with no obvious function, and reports that the damage comes largely from captive orcas grinding their teeth on tank walls [9].

Do elephants live shorter lives in zoos?

They used to, but a 2026 analysis of zoo records found that since 1992 elephants in zoos have survived as well as or better than the wild and semi-wild populations it compared them with (Sach et al., 2026) [11]. The earlier evidence came from Clubb et al. (2008), who used data on over 4,500 elephants to show that those in European zoos had about half the median life span of elephants in protected populations in their home countries, a gap clearest in Asian elephants [10]. Sach and colleagues, funded by the Zoological Society of London and by Species360, the non-profit that manages zoos’ shared animal records, analysed records from 1960 to 2024. They found that since 1992 female African elephants in zoos have survived about as well as the wild population of Amboseli in Kenya and males better, and that Asian elephants of both sexes have outlived the working timber elephants of Myanmar, the population Clubb had compared them with [11]. Calves were the exception: in that period, infant survival in zoos was lower than in the comparison populations for Asian elephants and for African females [11]. The authors add that longevity alone is not an adequate measure of welfare, since elephants can survive for many years in poor physical or psychological health [11].