Posted by:
dustyrhoads
at Sat Jul 3 00:57:30 2010 [ Email Message ] [ Show All Posts by dustyrhoads ]
Hey, Aaron. Thanks for your response. Very appreciated. I'll respond to your individual points below.
>>Species are going to vary greatly in their abilities to repopulate and the techniques for successful repopulation would vary just as greatly. I will adress just one point, the notion that exact locality would be required. How do you know this?
From research. Look at Richard King's work with Nerodia sipedon (see the link I posted earlier). Mainland watersnakes are banded, while only patternless Nerodia survive to reproduce on the Lake Erie islands. (The bandeds that immigrate to the islands are markedly predated upon by birds more than the native patternless, and a significant percentage of bandeds do not survive there, while a significant percentage of patternless DO survive on the islands. This is due to camouflage.) If you were a conservation biologist with the responsibility to save the species by repopulating the islands, which locality would you choose, based on the science? Island "patternless", of course. There's a genotype, phenotype, and a locality involved. And all three of those components are obviously important.
My main points are that (1) reintroduction programs should be based in science, (2) lay hobbyists aren't scientists and have nothing to show for the claims that producing "normals" will one day "save the species from extinction", and (3) even if it were left up to hobbyists to save species, it's not as simple as producing "wild types". As someone who has studied conservation biology, there is a component of reintroduction programs that involves assessing the competence of the stock you plan to reintroduce. You can't just blindly release any phenotype or genotype anywhere in the species' range and hope for the best. It's not a layman's work.
For mammalian species, assessing the competence would include training on how to find food, how to become part of a herd or pride, etc. Of course, snakes are born precocious -- knowing how to take care of themselves without parental help, so assessing the competence of a snake involves genetic competence, almost entirely.
Subocs do not simply match their surroundings, it's not that simple. I have seen hundreds of subocs in the wild and there is a great amount of crossover in appearance between localities. The notion that you would need Panther Cyn. subocs and only Panther Cyn. subocs would do if you wanted to repopulate Panther Cyn is not an absolute fact. The more reasonable assumption is that nearby localities and even far away localities probably contain very similar genetic material, enough so that some of them would survive.
Yes, again, some probably would survive; snakes do migrate, habitat environments do change (usually slowly), and in sexual species there is always genetic variation even in a single clutch of Panther Canyon babies, for instance. But you're talking about something that's analogous to the signal-to-noise problem in broadcast television and radio. The bigger the size of the tv antenna (in our case, the bigger the sample size looked at), the more you will see that random fluctuations in reception are averaged out (i.e. crossover in appearance between localities are shown to be the exception to the rule, not the norm), and the signal becomes quite clear (i.e. there is a general pattern of evolutionary lineages that pertain to a population). For this reason, large studies on a genomic scale, would be more indicative of predicting survival than a shot in the dark, simply because there is some anecdotal observation of crossover between locality types.
>>The question was not what is better, captive breeding or habitat preservation. Obviously habitat preservation is better. Yes there was a false impression in the hobby that our pets could be more useful than it turns out they could be but don't say it's absolutly impossible and throw out the baby with the bathwater.
Show me just one single instance of non-scientist hobbyists successfully reintroducing an endangered or threatened species back into the wild to save them from extinction, and I'll save the baby. 
Thanks for your comments, Aaron. I'm glad you chimed in.
DR
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RE: the Noah's Ark method of conservatio - dustyrhoads, Sat Jul 3 00:57:30 2010