Zoo animals with self sustaining captive populations

None of the private pheasant keeper I know keeps them for hunting.
You don't shoot a bird worth hundreds of euros alive!

For pheasant enthousiast I would highly recommend 'Fazanterie de Rooie Hoeve'
in the Netherlands: last time I visited I counted 40 pheasant taxa,
including very rare species. It is a shame the green junglefowl left the collection,
as they used to have all four species of wild junglefowl. (The other three are still there).
Luckely I had the chance to photograph the birds before they left.

 

An intresting case of a species with a self-sustaining captive population is the Mishmi takin with a founder-population of 2 males and 1 female ! For more information, see this thread: http://www.zoochat.com/2/mishmi-takins-captivity-405868/?highlight=takins+captivity

 

Zoo conservation plans normally aim for survival of 95% of genetic diversity in 200 years or similar numbers, not for a fixed number of generations. If you look at websites of EAZA or AZA, you can find reports of many species survival plans.

If you wish to look for animals which are already bred for 10 generations without the influx of fresh blood, you should look for species bred in hunting reserves and menageries. Conservation breeding in zoos started on a large scale 30-40 years ago, so much less than 10 generations of all but shortest-living animals.

 

Large numbers of ring-necked pheasants are reared for release by gamekeepers on estates with organised shoots. They are not native to the UK and all are hybrids, as many subspecies have been imported over the years. The carcases are eaten of course. The other species, kept by aviculturists, are known as ornamental pheasants.

On the list of self-sustaining species, I think that many of these species are the medium or large ungulates kept in deer parks and game ranches as well as in zoos. These would surely include American and European bison, eland, nilgai, blackbuck, both species of waterbuck, perhaps sitatunga and greater kudu, axis and hog deer, sambar, several races of sika, possibly barasingha and certainly Przewalski's horses. There may not be accurate records for all of these species over 10 generations without importations from the wild, but I reckon they are secure for all practical purposes and there may well be other similar species in the same situation.

Alan

 

Thanks Alan the list you give is just what is required. Many ungulates clearly do well and have long term populations. What ungulates do not do well in captivity?

The Mishmi Takin is very interesting showing that some inbred populations can thrive in captivity? Does it reach our criteria of ten generations and 100 animals?

Zoos have plans to maintain 95% of genetic diversity for a century or more which seems unrealistic for most species. Generations are a much better unit to measure sustainability against rather than years since generation time can vary so much.

I appreciate that conservation breeding in most animal collections has only been going for 30-40 years, although this is long enough to reach ten generations in most of the birds and smaller mammals.

For conservation breeding to be successful we have to understand the processes underlying the success and failure of captive populations. If we do manage to keep populations for multiple generations then we have to be able to avoid the process of domestication which will inevitably reduce the fitness of the species to survive in the wild. Even if we do manage to maintain 95% of genetic diversity I still suspect that there will still be strong positive selection for docile, promiscuous animals in captivity.

Many species do well in captivity, although most species die out in a few generations. Understanding the processes involved will enable us to manage captive populations more effectively for conservation purposes.

 

A good question, which deserves a good quantitative answer - which would itself deserve a PhD in conservation biology. But I can only answer it as a fairly knowledgeable zoo-goer; so don't take this as gospel
I think it is obvious that smaller ungulates are less likely to do well than larger ones: many species of duiker, dik dik, chevrotain and gazelle have done quite well for several generations but eventually died out. I suspect that springbok and Chinese water deer might pass the 10 generations test and southern pudu may be close to doing so, but I can't think of any others. With advances in veterinary medicine, nutrition and husbandry techniques I am sure that more species will qualify in time.
Many of the other species which do not thrive in the long term are from specialised habitats. I can think of examples such as saiga, Dall sheep, Hunter's antelope (hirola), gerenuk, pronghorn, musk deer and musk oxen.
Of course the exact reason for failure is likely to be different in each case. In a small population it may just be bad luck, for example a series of male births skewing the sex ratio. Several years ago I had a very interesting talk with the curator of a collection with a range of unusual ungulates and he described the vulnerability of some of these species to diseases common in local sheep and deer. In other cases the husbandry of these species is still under development, for example I am surprised by the number of different ways that I have seen chevrotains housed in zoos: they seem to be relatively delicate creatures which often appear uncomfortable in their exhibits - although I realise that this is a very subjective view.

Alan

 

The other area where there are self sustaining captive populations are various fish. There are self sustaining populations of many species of Goodeid livebearers, and also certain cichlids - Bristol is breeding and displaying various species of Lake Barombi cichlids. For these I expect there are also self-sustaining populations purely in private hands - the specialist aquatic societies may have dedicated projects for these. For various phasmid species there are also self-sustaining populations in culture, some for much more than 10 generations.

 

Very interesting topic and some great information. A problem for Zoos with these worthy breeding projects (esp. larger species) is the need to have several enclosures dedicated to a single species for many years and also surplus males. The average visitor will except to see a different species in each enclosure. Fortunately smaller mammals and birds and fish are much easier to house and breed for several generations and there is less problem with moving surplus animals to other collections.

 

Some time ago I read that chevrotains didn't like open spaces (due to them being forest animals,) and that people who where successfully/possibly breeding? chevrotains kept them in rabbit hutch-style enclosures. In modern times they seem to be kept largely in the bottom of planted out aviaries.

 

Browsing species are usually more difficult than grazers. Pronghorn and some gazelles thrive only in large dry paddocks in dry climate. Some Arctic and high-altitude species also prefer cold climate.

You could read about species like Pere David Deer and Laysan Duck which have the same or smaller founder populations.

Certainly over 100 of SSPs have this aim and new ones are coming.

Some species and groups are known to be difficult to keep. Many leaf-eating primates and seabirds for example.

But usually the problem is that the population was small and not enough interest was generated. Conservation biology shows that species can thrive with very low founding population, but more dangerous is low population for several generations, which can fix detrimental gene versions and makor make population die from casual effects (like casual skewing of proportion of sexes or accindental deaths).

 

This shows how it is important to know your species and to provide it with conditions that replicate what it would encounter in the wild.

 

This nicely illustrates why zoos should specialise in species that do well in their climate, many species do well in the UK temperate climate but a lot really are not at their best.

 

Good points, however because zoos set up SSP breeding programmes does not mean they will succeed, there have been many failures and I would like to know if anyone has looked at this in any detail. Why some programs just do not succeed. Some of the reasons for failure have been highlighted, inbreeding is clearly a big one. Some species survive population bottlenecks others do not.

Many species are unlikely ever to do well in captivity because of their life-history and ecologies. It would not be desirable to keep pelagic seabirds such as petrels but I suspect we will learn to keep many of the more delicate primates eventually. But even with primates we have lost a lot of species from zoos in recent years. What species have self sustaining captive populations?

 

As someone mentioned, lack of space is certainly a factor. AZA accredited zoos may not have enough space to maintain large enough populations of certain species. This is why many zoo professionals from non-AZA facilities (and also some observers like myself) feel that the AZA needs some policy changes. I realize they do work with some non-AZA facilities, but if they were to do this more freely there could be plenty of space readily available. I realize (and agree) that there needs to be some kind of assurance of animal care, so I am NOT saying they should work with every roadside zoo out there. But if a rich guy with a large ranch wants to have Pere Davids deer or cheetahs or whatever else and he has the money and means to care for them and help the species, then why not avail yourself of that resource?

 

I think co-operation with private breeders is essential for the sustainability
of many species. For some species that can be exchange of animals while for
other species exchange of knowlegde can improve the situation.
But I agree with Arizona Docent that some kind of assurance of animals care is needed.

 

The standards of some private breeders are as good as any zoo, although as a whole, private people can be difficult to work with since they are often not properly regulated, and do not always follow genetic guidelines. In the private sector selection for colour morphs, size, behavioural characters such as docility, and the breeding of hybrids is common. Although that does not mean there are not highly responsible people that zoos can and should work with.

 

Private individuals can contribute significantly to certain breeding programmes, without actually breeding any animals. For example by holding spare males which may eventually be required for breeding or by holding older stock which appear to be past breeding. I did this with some old aquarium stock from Chester, giving more room for the next generation at the Zoo and giving me the opportunity to photograph the fishes and to publicise the programme within the aquarium hobby.

Alan