Making room on the ark – can rare zoo animals replace common ones in Europe?

Introduction

Several threads discussed that zoos lack space for breeding programs, and proposed planned extinction of many animal species in European zoos. There are diverse alternatives, for example lobbying for an exemption in laws for zoos to allow limited import of founder animals. Another solution is replacing common zoo animals by rare species.

I decided to check current populations of common animals in EAZA zoos, focusing on those which could potentially be replaced by rare relatives. For this purpose, I downloaded current holdings of most common animals from Zootierliste (ones with over 50 holders, with some exceptions).

This is a thought experiment 'what if'. I simply want to check how many common animals exist in Europe, for a theoretical possibility. Are all common animals replaced by endangered species already? I also want a broad overview, not very specific details.

I don't plan in any way to influence zoos, coordinators of breeding programs or EAZA. Still, I demonstrate that for several animal groups, even if a fraction, for example one-fifth of holders of common animals switch to rare ones, this would give concrete and important conservation benefit.

In practice, it is not realistic that all or most non-endangered and common animals listed below can be replaced by endangered species. Zoo holdings have errors, exhibits may be outdated and awaiting replacement, small zoos may lack experience of keeping rare species, common animals might be rescues, and long-lived species, like apes, bears, parrots, cranes, turtles and crocodilians can live decades into future before freeing space.

I expect an argument that zoos should keep common and domestic animals for education. This can be counteracted. First, zoos can use rare animals to educate about native animals. A zoo can e.g. educate children about deer with endangered Bactrian red deer instead of common generic red deer. Second, zoos obviously cannot educate about everything, so already must choose topics of education. Better choose education which joins forces with conservation, because uses threatened species.

I also feel that education about domestic animals 'that milk comes from cows not factory' can be delegated to petting farms. it is not the core function of zoos. In the last decades, a worrying trend occurred in zoos - getting rid of elephants and black rhinos but acquiring cows and domestic goats. Is it really sensible?

Part 1. Hoofed Animals

Ungulates have been repeatedly mentioned on Zoochat in the context that zoo populationd of threatened species and subspecies fall. They are big animals which demand space but are seen as less interesting for the public than carnivores or apes. Lets examine check this group.

1. Deer

Following deer forms I consider not endangered and commonly kept:
Eurasian Fallow Deer - 866 holders
Central European Red Deer - 324 holders
European Roe Deer - 243 holders
Reindeer (domestic) - 183 holders
Red Deer (generic / no-subspecific status) - 165 holders
Eurasian Elk - 125 holders
Axis Deer (generic) - 100 holders
Sika Deer (generic) - 100 holders
Dybowski Sika Deer - 84 holders
Japanese Sika Deer - 63 holders
Chinese Muntjac (generic) - 181 holders
In total, 2434 institutions keep generic or common deer, which means over 10,000 individuals, many in small deer parks or enclosures.

Deer show how conservation could benefit if even a fraction of institutions keeping common species would make a bold decision to change to endangered ones. This would require increased cooperation of EAZA with numerous and relatively small non-EAZA institutions.

In an imaginary scenario, if all institutions changed to endangered deer, this could create space for 20 forms, 500 individuals each of endangered deer. Even if only 1 in 5 changed, that would solves space problems of several endangered deer.

Among deer, many endangered forms, like Mesopotamian Fallow Deer, Atlas Red Deer, Bactrian Red Deer, Vietnamese Sika Deer have very similar appearance and needs as their common cousins. Deer could be also replaced by endangered caprids and antelope. For example, some of 125 institutions keeping Eurasian Elk (Moose) could hypothetically, switch to keeping Takin.

Remark: Native population of Chinese Muntjac was apparently recently uplisted to Vulnerable with extinction and might be theoretically excluded. But its large introduced population in Britain means that I included it among forms where more endangered replacements are possible.

Below - Vietnamese Sika Deer by Therabu. Extinct in the wild, similar to common generic sika deer, and at one time threatened in European zoos due to the lack of holders.



Vietnamese sika deer Cervus hortulorum pseudaxis - ZooChat

2. Caprids – wild sheep and goat

Following forms are not endangered and commonly kept:
Mufflon - 457 holders
Aoudad (generic) – 129 holders
Alpine ibex - 109 holders
Alpine Chamois – 48 holders
Cretan and Bezoar Wild Goat (hybrid) – 16 holders
In total, 759 zoos keep these generic, common or feral caprids, which is probably much more than 5,000 individuals. Additionally, enormous number of domestic goats and sheep are kept in zoos, which are not really the wisest use of zoos space.

Wild sheep and goat are another group, which conservation would enormously benefit if institutions keeping common forms boldly witch to endangered ones. As with deer, many endangered caprids have very similar appearance and requirements to common ones, e.g. Tajik Urial, all pure subspecies of Aoudad and West Caucasian Ibex. As a side remark, it is possible that zoo population of aoudad sheep is partially pure subspecies, because it could be imported from only one part of its range.

Below: Transcaspian Urial by RatioTitle. Endangered, and with very similar needs to the common Mufflon.

Transcaspian Urial (Ovis vignei arkal) - ZooChat

Coming next – the rest of ungulates.

 

Why are Aoudad not threatened. They are listed as Vulnerable.

 

Generic Aoudad have 0 conservation value, especially as genetics point to the existence of 2 clearly defined (sub)species, one on the coast, the other in the Sahara interior. Unfortunately pure stock of aoudad is very rare and the genetics probably not that bright...

 

The following deer are listed in ZTL:
Vulnerable: American woodland caribou, Chinese water deer, Eurasian forest reindeer, Indian swamp deer, Javan rusa, Sambar, White-lipped deer
Near Threatened: Michie's tufted deer, Southern pudu
Endangered: Burmese brow-antlered deer, Common hog deer, Persian fallow deer, Visayan spotted deer
Critically Endangered: Bawean deer
Extinct in the wild: Pere David's deer

 

3. Equids

Following forms are not endangered and commonly kept:
Grant's Zebra - 170 holders
Chapman's Zebra - 102 holders
Tarpan-type horse - 44 holders

272 holders keep two commonest zebra subspecies. The situation of zebras are very different than deer or caprids. They are popular ABC animals, and lots of zoos reserved space for zebras. Therefore there is enough place in zoos to maintain self-sufficient populations of world's all zebra forms: endangered Maneless or Selous Zebra, Grevvy's, Hartmann's and even Cape Zebra, if the last one ever becomes available.

In contrast, Somali Wild Ass and Asian Wild Asses (Kulan and Onager) are endangered, but are not self-paying visitor favourites. Here, 44 holders of tarpan and possibly some holders of domestic horse breeds could go a long way to help. Interesting possibility is releasing Kulan or Onager in rewilding reserves throughout Europe, like it has been dne with horses. Genetic research shows that Asian Wild Asses are the same species as the Pleistocene Equus hydruntinus which lived in temperate Europe.

Below – Maneless Zebra by Elephantelephant. Neglected but became very threatened in the wild.

Maneless zebra - ZooChat

4. Wild Cattle

Following forms are not endangered and commonly kept:
Prairie Bison - 102 holders
Domestic Yak - 168 holders
Watussi/ Ankole cattle - 132 holders
Dwarf Zebu - 106 holders
Zebu (no race) - 15 holders
Additionally, domestic cattle are kept in countless institutions aimed at wild animals. There are 126 breeds (not even holders or individuals!) of domestic cows.

Wild cattle are the group with big potential to change from common to rare animals. Somewhat ignored because of the humble domestic cow, but are important in many ecosystems, and most species and subspecies are threatened in the wild. For zoo purposes, they could be divided into frost-hardy and tropical forms.

270 holders of common prairie bison and domestic yaks could make big difference in conservation. Threatened European Bison still lacks new holders, and the European Bison conservation plan laments that an animal rarer than the Giant Panda is culled because of lack of space. Also, it strongly needs education and popularity for reintroduction in Europe, where most people completely lost the cultural knowledge that it lived on their land, and treat return of the bison with great suspicion. Even small zoos and wildlife parks can help there.

Tropical cattle - wild Banteng, Gaur and Anoa are all threatened, and would benefit from just a fraction of 253 places of domestic zebu and Watussi. Interestingly, Banteng are tameable and have calmer disposition than Aurochs-derived European cattle, so may be even tried in smaller institutions with closer contact with animals.

Below: European Bison or Wisent by KevinB – still rarer than the Giant Panda.

Wisent (Bison bonasus), 2021-12-07 - ZooChat

Bali cattle or farmed Banteng by Nandito. Allegedly, Banteng are very tamable.

(July 2020) Kembangan, Jakarta - Bali cattle (Bos javanicus domesticus) - ZooChat

6. Wild pigs

Following forms are not endangered and commonly kept:
Central European wild boar - 358 holders
Collared peccary (generic) – 85 holderrs
Wild boar (generic) – 51 holders

494 holders keep three common species. Surprisingly many wild boars are kept in larger zoos, not just wildlife parks which lack facilities to keep tropical pigs.

Most species and subspecies of wild suids are threatened in the wild, are important ecosystem engineers, but are neglected because of their domesticated relatives. Most of these species are tropical, but still can benefit from some spaces. Recently, Bearded pigs die out and Babirussa struggle because of lack of holders.

Below – Bearded Pig by Fat-tailed Dwarf Lemur, the last individual of its species in Europe.

Bornean bearded pig - ZooChat

7. Giraffe and Antelope

Following forms are not endangered and commonly kept:
Eland (generic) – 129 holders
Blackbuck – 113 holders
Nilgai – 75 holders
Giraffe (generic) - 72 holders.

317 holders keep 3 common antelope. They could potentially support several more species of antelope, or maybe exotic deer or caprids. Likewise, generic giraffe could potentially provide space for at least one more giraffe form. Nevertheless, there are relatively fewer common antelope than deer or caprids.

Below – the elderly Kaama Hartebeest by Lintworm. The last of its species in Europe.

Kaama Hartebeest - ZooChat

Coming next – carnivores. Are lion and tiger subspecies really too expensive to save, and snow leopards rare?

 

Yes, and in addition there are several endangered subspecies of Red Deer like Bactrian or Atlas, which are perhaps not separately listed in the IUCN,

 

What do you mean by ‘tarpan-type horses’: the more primitive breeds generally, or the Konik alone?

The future of the onager, particularly the kulan, is in rewilding and reserves, not zoos, in my opinion. You can’t easily replace zebras with the onager or the African wild ass, as many are held in mixed-species savannah exhibits where the onager and African wild ass don’t belong.

Plus, few holders of domestic horses will have the expertise required to work with wild equids, so that’s not too viable an option either. And zoos that hold domestic horses often hold endangered breeds, so it’s unlikely they’d be willing to phase them out.

 

Carnivores

8. Lion and Tiger

Following are commonly held in Europe and/or EAZA:
Lion (generic) - 275 holders
Siberian Tiger - 188 holders
Tiger (generic) – 182 holders

Lions and tigers are eternally popular. They were kept in a zoo in Assyria already 4000 years ago. Today there are 275 holders of generic lions, and 182 holders of generic tigers in Europe. One can add that zoos in other continents keep large number of lions and tigers, too.

Therefore world's zoos have capacity to save self-sustaining populations of all extant subspecies of lions (six to nine) and tigers (six).


9. Spotted big cats and puma

Following forms are commonly kept:
Jaguar (generic) - 103 holders
Leopard (generic) - 74 holders
Puma (generic) - 114 holders
Snow Leopard (generic) – 102 holders
South African Cheetah - 127 holders

291 holders of generic leopards, pumas and jaguars show that other large felids are very popular, too.

Therefore, there is a realistic space to maintain all endangered subspecies of Leopard (Persian, Arabian, Sri Lankan, Indochinese, Javan, North Chinese and Amur) in zoos. There are additionally numerous zoo holders in other continents, of course. One subspecies which can benefit is Javan Leopard with the population of ca 319 mature animals, which is about 20 times rarer than Giant Panda or Snow Leopard.

Snow Leopard came as a surprise to me – the 'ghost of the Himalayas' already has a big population in human care, especially considering zoos in other continents. In the big picture, it would make sense if a proportion of zoos switched from Snow Leopards to endangered subspecies of Leopard. Likewise, South African Cheetahs could make space to Northeast African Cheetahs or Leopards.

NB, genetic studies of Jaguars and Pumas show that both are very uniform genetically, and for Snow Leopards suggests two subspecies, which are mixed in zoos.

Conclusion: Zoos have exhibit space to preserve all endangered subspecies of big cats, due to the popularity of big cats in zoos. If any subspecies of big cats goes extinct, it will be because zoos could not obtain founder animals from the wild, and not because of lack of space or breeding expertise.

Sadly, few years ago, one conservation institution claimed that it is unrealistic to preserve all forms of big cats. This culminated in the proposal to merge previously recognized subspecies of lions and tigers in conservation plans into just two each. It was followed by merging the previously recognized subspecies of Lions on IUCN red list, where the said report probably played a big part. The real numbers of zoo holders show a very different picture, and much more optimistic one!

Below: a lioness of unknown origin within the range of critically endangered West African Lion. About 400 of them remain. Photo by Fawaz.tairou on Creative Commons, Creative Commons Attribution-Share Alike 3.0

File:Lionne du Cameroun.JPG - Wikipedia

So that the next photo will not make some viewers very sad, South China Tiger by baboon. Extinct in the wild, surviving only in zoos in China. Which don't like to share, but at least are numerous enough to protect this form themselves.


South China tiger emerging from the bush - ZooChat

Javan Tiger by TheoV – what remains of it. Its extinction is doubly sad. When only few individuals remained in the wild, zoo biologists proposed breeding them in zoos. This offer was turned down by over-optimistic field conservationists.


Javan tiger [2015] - ZooChat

Very alive Javan Leopard by Robreintjes. The largest remaining predator on Java, about 300 remain. It will need insurance population forever. Simply, too little habitat remains on the densely populated Java.

Javan leopard - ZooChat

Some sources:

Henschel P, Coad L, Burton C, Chataigner B, Dunn A, MacDonald D, et al. (2014) The Lion in West Africa Is Critically Endangered. PLoS ONE 9(1): e83500. The Lion in West Africa Is Critically Endangered

Kitchener, et al. A revised taxonomy of the Felidae : The final report of the Cat Classification Task Force of the IUCN Cat Specialist Group. CATnews Special Issue 11 Winter 2017. https://repository.si.edu/handle/10088/32616

Wibisono, H., Wilianto, E., Pinondang, I., Rahman, D.A. & Chandradewi, D. 2021. Panthera pardus ssp. melas. The IUCN Red List of Threatened Species 2021: e.T15962A50660931. IUCN Red List of Threatened Species. Accessed on 29 August 2022.

Coming next - other carnivores.

 

The bearded pig picture is mine, neo is his name.

 

This is what Zootierliste says. Because konik or tarpan-like horses are often kept semi-wild, they could be potentially replaced by wild equids. Please note that I share much of your concern - see the introduction.

 

I don't have a problem with replacing generic big cats with pure subspecies, as long as there is a reintroduction programme. If there isn't, it would be better to preserve the subspecies in situ, rather than reducing the number of endangered species and genera of animals kept in zoos. There are various endangered species of carnivores that are neglected in situ and ex situ.

 

Indonesia has a huge human population and growing economy. And increasing number of zoos. Would it not be better to leave creation of coordinated insurance captive population to them?

 

Perhaps an interesting point - with Singapore Zoo + Night Safari recently admitted into the EAZA, it could theoretically be possible for some director to import either of these species, albeit quarantine times would likely be something of an issue..

 

This would be optimal. However, look at large carnivores in Europe and North America. Often 100 or more years passed between they went extinct and were reintroduced.

Indonesian zoos don't have space to preserve a large numbers of Javan leopards. More generally, foreign zoos have a role to protect animals from dangers which will hit animals both in the wild and zoos in their native countries. Economic crisis and epidemics, for example. Not to say that Indonesia is especially prone to crisis - the European Bison in my previous post was 3 times almost wiped out by wars and revolutions, and epidemics also threatened them.

Would be great!

 

Other carnivores


10. Lynxes

Following not threatened forms are commonly kept in Europe:
European Lynx - 217 holders
Eurasian Lynx (generic) – 125 holders

342 holders keep generic and European lynxes. This theoretically space to preserve threatened forms, especially Balkan Lynx, recently recognized as a distinct and Critically Endangered subspecies with as few as 20-39 surviving wild adults in Macedonia, Albania, Kosovo and Montenegro. And, of course, Iberian Lynx.

Below: Iberian Lynx by Giant Eland. One cat where breeding in human care and release truly contributed to its recovery.


Iberian lynx (Lynx pardinus) - ZooChat

Reference:
Melovski, D., Breitenmoser, U., von Arx, M., Breitenmoser-Würsten, C. & Lanz, T. 2015. Lynx lynx ssp. balcanicus (errata version published in 2016). The IUCN Red List of Threatened Species 2015: e.T68986842A87999432. IUCN Red List of Threatened Species. Accessed on 01 September 2022.


11. Otters

Following forms are commonly kept in Europe:
Asian Small-clawed Otter - 287 holders
European Otter (nominate) - 142 holders

There are 429 holders of two otter forms in Europe. Otters are both popular ABC animals, and threatened as a group. This shows a conservation potential, as space exist to keep a self-sustaining population of at least 2-3 more threatened freshwater otter species. So far, only Smooth-coated Otter is a candidate for replacement kept in Europe. There are several other threatened otters in South Asia, Africa and South America, but not kept outside their home countries.

Below: Smooth-coated Otters by MagpieGoose. Threatened and allegedly most sociable otter, which thrives in zoos.


Indochinese smooth-coated otter - ZooChat



12. Tropical small cats and other small carnivores

This is taxonomically loose group with relatively similar requirements. Following forms are commonly kept in Europe:
Serval (generic) - 185 holders
Caracal (generic) - 69 holders
Ocelot (generic) - 54 holders
Fishing Cat (generic) - 48 holders

Meerkat - 622 holders
South American coati (generic) - 443 holders
Zebra mongoose (generic) - 97 holders
Yellow mongoose - 95 holders
Dwarf mongoose (generic) - 78 holders
Binturong (generic) - 68 holders
Kinkajou (generic) - 65 holders

There are 356 holders of 4 smaller tropical cat species, and 1468 holders of small carnivores of which only the Fishing Cat and Biturong are threatened.

This list proves the Zoochaters' opinion that small carnivores are unpopular in zoos, except of a handful of species considered cute for the public - especially notorious meerkats. Today it is impossible to maintain the diversity of species seen in zoos in the past.

Nevertheless, zoos could fit a breeding plan for several endangered small carnivores. They could be Madagascar carnivores, Palawan Binturongs or one of many tropical cats and other carnivores not kept in Western zoos, which are threatened - or just unstudied.

And the notorious Meerkats? No other carnivore combines anthropomorphic face with forward-facing eyes and the habit of standing bipedally. These are probably best replaced by ground squirrels.

Below: Grandidier's Vontsira by Tomek – recently discovered and threatened.


Grandidier's Vontsira (Galidictis grandidieri), October 2020 - ZooChat



13. Temperate small cats and other small carnivores

Following forms are commonly kept in Europe:
Northern raccoon (generic) - 548 holders
Western red panda - 194 holders
European Red Fox - 178 holders
Striped Skunk (generic) - 168 holders
Raccoon dog (generic) - 154 holders
European Wildcat - 141 holders
Polar fox (generic) - 115 holders
House cat (no breed) - 112 holders
European badger - 104 holders
Stone marten (generic) - 86 holders
Red fox (generic ) - 66 holders
Silver fox (domestic) - 61 holders
Corsac fox - 60 holders
Pine marten - 50 holders

2037 holders keep commoner temperate carnivores. Of these, only Western Red Panda is globally threatened, and European Wildcat is locally used in reintroduction.

Even if many of small temperate carnivores are rescues or former pets, space exists to keep self-sustaining populations of further species or subspecies. The main problem is that very few threatened temperate carnivores are kept in the region. I can think of European Mink, Marbled Polecat, Eastern Red Panda and Scottish Wildcat – if the latter really is a distinct subspecies.

And, if zoo community would make an effort to acquire and breed Cozumel Raccoons, Darwin's Foxes or similar, space at least already exists for them.

Below: Scottish Wildcat by ro6ca66


Scottish wildcat : British Wildlife Centre : 05 Oct 2018 - ZooChat

Cozumel Raccoon by ralph. Just as cute and adaptable as its northern cousin, but Critically Endangered on the tiny island off the coast of Mexico.


Cozumel raccoon (Procyon pygmaeus) - ZooChat



14. Bears and large canids

Following forms are commonly kept in Europe:
European Brown Bear – 179 holders
Brown Bear (generic) – 116 holders
Wolf (generic) - 156 holders
Timber Wolf - 54 holders

There are 505 holders of wolves and, often rescued, brown bears. The situation from the conservation perspective is different than big cats which multiple threatened purebred subspecies are maintained in studbooks.

Bears are long-lived and rescued bears will live for decades. However, slowly, space will appear to allow a meaningful conservation program for other bears or, for example, Dholes.

Below: Sloth bear by Joseph G. One of several threatened bears, rather neglected in favour of common brown bears.


Sloth bear - ZooChat

Coming next – primates.

 

Where would large carnivores be introduced? Do you honestly think that densely populated countries would want large carnivores, which associate humans with food, to be introduced into their countries with a risk of the carnivores killing people and their livestock

Does Java have enough space to introduce a viable population of Javan leopards?

 

Given the laws regarding Raccoon in Europe, I think with that species in particular there would arise some difficulty in creating a breeding population ...

 

I agree. Otters are represented by the Asian small-clawed otter in many zoos, as if other species don't exist. This species is Vulnerable, which is one of the problems with this thread. Some species are threatened in the wild but are over-abundant in captivity.

There are many species of threatened small carnivores that could be bred in captivity and be part of reintroduction programmes.

I don't agree that the list proves that small carnivores are unpopular in zoos. I suspect that many zoo directors believe this to be the case. There are many books and TV programmes that show obscure species. Would they do this if they thought people wouldn't be interested in them?

That's an interesting idea. Rein Stuurman used a ground squirrel to depict a yellow mongoose in 'Wild Animals of the World' by T.L.C. Tomkins.

I'd like to see such species in zoos. An enclosure occupied by a few large carnivores could be converted into a few enclosures for smaller species

 

Regarding ground squirrels as a Meerkat replacement, I doubt most visitors could tell apart a Meerkat and a prairie dog. Obviously Black-tailed Prairie Dogs are not threatened and seen in zoos far too commonly. The Endangered Mexican and Utah Prairie Dogs could make excellent replacements for either the Black-tailed Prairie Dog or Meerkats.

 

That wouldn't make as much sense since most meerkats are kept in Africa themed areas so putting prarie dogs in former meerkat enclosures would not work well.

I'd also ask why go through the paperwork and quarantine measures to bring endangered North American animals to European zoos when they could be bred in the US or even just be left at their habitats. And I say this as someone who rather have them in captivity more often.

The best thing that could be done is to educate the public about endangered prarie dogs through black-tailed prairie dogs or raise funds for them. This could be applicable for many other commonly kept species. After all, they are not just ambassadors of their specific taxa. They are also also a ambassador for their relatives as well along with their habitats.