private collections ever been used to repopulate...

[josh raysin]

have any animals from private collections ever been used to repopulate natural habitats?

i personally like working with many different species.

[bbrock]

Originally Posted by josh raysin

have any animals from private collections ever been used to repopulate natural habitats?

i personally like working with many different species.

To my knowledge no, but perhaps Ed could provide a better answer if he is watching.

But this is precisely why we formed the ASN. Private breeders have the husbandry and breeding skills to propagate animals as good, or better than, zoos. But in general the private breeders lack training in conservation science, record keeping protocols, and disease management to produce offspring suitable for reintroduction. To successfully conduct a captive breeding program for reintroducing animals to the wild is a highly technical process that requires knowledge about population genetics and disease management as well as husbandry and breeding skills. So it should be no surprise that private collections are rarely, if ever, used for reintroduction. In fact, it would be shocking if they were. But ASN wants to change that. Private breeders are the best of the best regarding skill in general husbandry and breeding and ASN will provide training and organization in the other areas to mould our skills into a useful resource for conserving wild amphibians. There are a few successful models out there to indicate this is possible. The question is whether we are up to the challenge.

[defaced]

What is the ASN? Site/background info/purpose?

[bbrock]

http://www.treewalkers.org

Go to the projects link

[kyle1745]

Also the post here:
http://www.dendroboard.com/phpBB2/viewtopic.php?t=20490

[kyle1745]

In relation to releasing animals...

If frogs are raised in captivity and kept from food that would allow them to generate their toxins what would be the effect of releasing them? Could they gain toxicity from the food after release or do captive animals lose that ability all together?

[bbrock]

The evidence is they would regain the toxins. I don't have the citation handy but there was a paper that studied the Hawaiian auratus and found they contained toxins but the toxins were different from frogs in the ancestral population on Toboga. The inference is that the frogs are able to sequester a variety of akaloids to take advantage of what is available.

But this indicates the animals may need a "soft release" method where the animals are maintained in semiwild pens at the release site for awhile before being set free. This would give them time to accumulate toxins before being exposed to predators. Even better may be to deposit tadpoles in artificial phytotelmata and allow the morphs to complete their metamorphosis in the wild. Juvenile mortality would be higher but the survivors would be better adapted for life in the wild.

[955i]

Originally Posted by bbrock

This would give them time to accumulate toxins before being exposed to predators.

This should not be necessary unless the whole population in the area had been wiped out as any predators would already associate the colouration of the frogs with them being toxic

[Ben_C]

I don't have the citation handy but there was a paper that studied the Hawaiian auratus and found they contained toxins but the toxins were different from frogs in the ancestral population on Toboga.

Here's the paper I think bbrock is talking about:
Daly, J.W., Jr., S.I. Secunda, H.M. Garraffo, T.F. Spande, A. Wisnieski, C. Nishihira, and J.F. Cover, Jr. 1992. Variability in alkaloid profiles in neotropical poison frogs (Dendrobatidae): genetic versus environmental determinants. Toxicon 30:887-898.

I hope this helps,
B

[bbrock]

Originally Posted by 955i

This should not be necessary unless the whole population in the area had been wiped out as any predators would already associate the colouration of the frogs with them being toxic

In almost all cases, animals from captivity would never be released to the wild unless the species were completely extirpated from an area. Recovery of species in situ is always the preferred method under modern practices of conservation biology.

That said, there is a lot of debate over whether PDF are really aposematically colored to warn predators. D. auratus, for example, are almost certainly not as every I now who has seen them in the wild remarks at how camoflauged they are in the dappled shade. Regardless, warning colors only work as the result of testing and learning by predators. I can't remember if it was at the National Zoo in Washington DC or the National Aquarium in Baltimore where E. tricolor were released into the amazon exhibit and the birds began having a feast for awhile. Eventually things stabilized, possibly because the frogs built up toxins after foraging in the exhibit but the example serves to demonstrate that warning color alone is not enough. Of course that agrees with your point that if there were still some toxic wild animals in the area, then the predators would be pre-conditioned.