biodiversity in zoos

[Coelacanth18]

Objection, your hono(u)r! This depends a lot on the species in question. If you look at the larger picture of Megabat species variety, only few megabat species managed to establish themselves in sufficent numbers in captivity (Rousettus aegyptiacus and Pteropus rodricensis, in particular, come to mind), and without LBC's constant coordination, breeding success of these species might not be where it's today (not being that regular in all these species, btw.).

Without being able to cite anything, I assumed it was regular, since R. aegyptiacus, P. rodricensis, and Eidolon helvum, at the very least, have large self-sustaining populations, and births are frequently reported at several facilities. Whether Malayan and Indian flying foxes are well-established is questionable, since they are not quite as common and they are not globally maintained like P. rodricensis. Other megabat species (Wahlberg's epauletted, hammerhead, and Australia FFs) have indeed gone the way of the dodo in NA. You're right that few megabat species are well-established in the States, but bats are far from being the only underrepresented group in captivity so that alone does not surprise me.

As for conservation bat breeding programs, don't forget Jersey's Livingstone's fruit bat (Pteropus livingstonii) project.

Only forgot it because I was thinking about NA zoos in particular, which don't keep P. livingstonii, but yes.

Insectivorous microbats can live for longer periods of time in captivity if professionally cared for; I happen to know several specimens of European species kept in captivity due to not being fit for release and used for educational purposes. The labour input, however, and diet requirements as well as legal issues makes keeping such microbats unattractive for zoos.

I could have worded my statement better, I suppose. You're right that they can live for long periods of time, but this is not usually the case. In most cases, mortality rates are high. Too often they are improperly cared for, which can be especially detrimental for insectivorous bats because they die quickly if mistakes are made. The dietary requirements, legal concerns, and difficulty in seeing the animals all combine to make them unpopular exhibit animals. Additionally, the US has tried keeping colonies of insect-eating bats in captivity: one subspecies in particular, the threatened Virginia big-eared bat, was kept at the Smithsonian Conservation Biology Institute to create a security population and develop husbandry techniques. Within 6 months, 75% of them were dead (granted, some sources indicate the Smithsonian made some stupid mistakes that led to this outcome). This article details it here:

Smithsonian Science News –Captive colony of Virginia big-eared bats providing valuable lessons in battle against deadly white-nose syndrome

Why is it that vampire bats have declined so much in Europe? Zoos in NA don't seem to have a lot of trouble with them; they are actually quite easy to feed, rarely get sick, and they make popular exhibit animals because of their uniqueness.

Spectral bats are a species I would like to see in zoos. Granted, they would probably give a lot of people nightmares.... I guess that's why bat nerds don't get to make those kinds of choices

 

[temp]

@temp: I wouldn't say that pale spear-nosed bats are well established in European zoos

The wording I used was sufficiently established, which (in my head, anyway) isn't quite the same as well-established. I also noted "not as many as Seba's, but enough to keep them going". Of the five colonies in European zoos, at least three are decent sized with regular breeding. Obviously this few colonies means that they could disappear entirely, but it would require some bad luck.

BTW, while I do appreciated the explanations of why certain bats are more common in captivity than others, I am aware of the issues. My earlier comment on "South American coverage vs. coverage of other regions" was entirely because this was the actual question in the first post and the thread had gone in a different direction. My mistake if this wasn't entirely clear from my post.

Why is it that vampire bats have declined so much in Europe?

Strictly speaking we can't really say it has declined "much" because it was never well-established in good numbers in European zoos. I think the largest number of European zoos that have kept it on the same time was four and mostly very small groups. In comparison 15+ North American zoos including several decent-sized groups.

 

[gerenuk]

Why is it that vampire bats have declined so much in Europe? Zoos in NA don't seem to have a lot of trouble with them; they are actually quite easy to feed, rarely get sick, and they make popular exhibit animals because of their uniqueness.

A few years back the American population did decline quite a bit and was quickly boosted by imports.

 

[Batto]

Without being able to cite anything, I assumed it was regular, since R. aegyptiacus, P. rodricensis, and Eidolon helvum, at the very least, have large self-sustaining populations, and births are frequently reported at several facilities. Whether Malayan and Indian flying foxes are well-established is questionable (...)

The situation of Eidolon helvum is better in American than European zoos, but still not as good as, say Rousettus aegyptiacus; there have been whole population losses with no apparent reason (coronavirus-related?).

In most cases, mortality rates are high. Too often they are improperly cared for, which can be especially detrimental for insectivorous bats because they die quickly if mistakes are made.

Don't forget that a major amount of these bats end up in captivity because of health issues, decreasing their survival rate in general. It is indeed not easy to sustain insectivorous bats, and I'm basing this not just on book knowledge. Over the years, I've taken care of several bat species of different ages for release and relocation and been involved with bat rescue groups; loss rates can indeed be depressingly high. Still, I wouldn't generalize (also due to species differences), as some specimens have shown to be remarkably hardy. As already mentioned, however, a lot of work is involved in keeping them alive and well.

The dietary requirements, legal concerns, and difficulty in seeing the animals all combine to make them unpopular exhibit animals.

As already mentioned in my previous posts.
The Virginia big-eared bat project was a flop for some reasons, just as (unfortunately) other similar projects with other animals (including rabbits and quails).

The decline of vampire bats could be contributed to several reasons, including inbreeding depression and, as strange as it may sound, too large enclosures. Due to the Säugetiergutachten, Berlin Zoo, for example, had to increase their enclosure sizes. Since then, according to the curator, the breeding success has decreased significantly. Maybe smaller enclosures, as prevalent in US zoos and laboratory settings, make it easier to keep temperature and humidity levels more constantly, which are important factors for this species as well as other neotropical microbats.

I'm a big fan of spectral bats and other carnivorous bats. However, if you talk with bat researchers working in the field, you will hear again and again how rare these bats are. Therefore, obtaining them isn't easy, and shouldn't be enforced. And I wouldn't worry about them scaring visitors, though; most likely, people would be fascinated to watch them stalk and hunt prey.

 

[Batto]

The wording I used was sufficiently established, which (in my head, anyway) isn't quite the same as well-established. I also noted "not as many as Seba's, but enough to keep them going". Of the five colonies in European zoos, at least three are decent sized with regular breeding. Obviously this few colonies means that they could disappear entirely, but it would require some bad luck.

Fair enough. I've worked with P. discolor, and I've been getting the impression that their numbers (and the numbers of institutions keeping them) have dwindled over the years. It's no longer as easy to obtain them as it used to.

Given the diversity of species, bats are quite poorly represented in captivity, especially in comparison to rodents, the only larger mammalian order. Some if not most of the reasons for this have already been mentioned. However, I think that bats can be potentially well better represented; the already mentioned institutions and public training of megabats are on the right track.

 

[Yemo]

Hi,
just wanted to mention that the Dortmund Zoo specializes in South American species (of course there are some other species as well, but South America is clearly the focus).
The very successful breeding program includes giant anteaters, jaguars, oncillas, giant otters and tamanduas and others.

Tamanduas share the enclosure with giant anteaters, two-toed sloths and a variety of armadillos.