Guy and Tweeters,

You are probably correct when you say that animals released from
captive breeding programs into the wild generally have lower survival
rates than animals raised in the wild. However, what would you suggest
that we do-- abandon all captive breeding programs, and allow these
species to become extinct without any effort at restoration?

Captive breeding programs are a last-ditch approach when a species
becomes critically endangered, and nothing else seems to be slowing
the slide toward extinction. Release of captive-bred birds or animals
will not work unless one or more of the factors that originally caused
endangerment is reversed. These factors could include habitat loss
(probably the commonest cause of endangerment), competition with or
predation by non-native species, use of DDT or other persistent
pesticides (probably the main factor for Peregrines and several other
species), etc.

Despite whatever flaws they may have, captive breeding programs have
produced many notable successes. The Nene, Black-footed Ferret, and
Whooping Crane, among others, have been saved from extinction by
captive breeding programs. California Condors are a long way from
being successfully re-established in the wild, but they might have
become extinct already without captive breeding. It's a shame that no
one seriously tried to establish a captive breeding program for
Carolina Parakeets, or we might still be graced by the presence of
that species in the southeastern U.S.

In the case of hatchery-raised fish, it is widely acknowledged that
fish released from hatcheries have much lower survival rates that
those from natural populations. In Canada, at least, there is now far
less emphasis on hatcheries as a means of restoring salmon runs, and
far more emphasis on habitat restoration, than there was 20 or 30
years ago. Many hatcheries have closed in the last few years. However,
as Tweeters is a bird group, not a fish group, maybe we should stick
more to talking about birds.

If you are suggesting that captive breeding programs for endangered
species could be improved, perhaps by exposing captive-bred birds to
predators while they are still in captivity, I agree. However, if you
are suggesting that such programs be completely abandoned (it wasn't
clear from your message), I suspect that you will get little sympathy
from most of the members of this group.


Wayne C. Weber
Delta, BC
contopus at telus.net




----- Original Message -----
> From: Guy McWethy <lguy_mcw at yahoo.com>
> To: <Tweeters at u.washington.edu>
> Sent: Friday, March 19, 2004 9:14 AM
> Subject: Re: Eagle and Marmots - Captive Release Programs Rant
>
>
> > Tweets,
> > While this IS deplorable, the main problem I see with
> > the Marmots, is that the captive-raised Marmots are
> > incredibly naive, and do not recognize predators until
> > they get munched. Killing eagles is treating a
> > symptom, NOT addressing the problem.
> > This is the same problem encountered with almost every
> > captive breeding program I have heard of. Juvenile
> > hatchery-raised salmon smolt get decimated when
> > released into the wild until the survivors get
> > educated. Black-footed Ferrets - I think about 1/2 of
> > those released starve because they do not know how to
> > hunt, and the other half get picked off by predators.
> > The Thick-billed Parrots that were released in Arizona
> > a few years ago, almost all of the flock were picked
> > off by Goshawks because they did not know or have a
> > chance to learn the behaviour to watch for predators
> > from their wild compatriots. Released Condors are
> > munched by Golden Eagles as well.
> > I do remember hearing about a study with Salmon smolt
> > where one group was put in a tank with a Ling-cod and
> > 'educated' before release into the wild. Watching
> > your buddies get eaten might be considered an
> > education for the survivors ;) I believe that the
> > study group did show better return/survival rates than
> > the control group in that study.
> > Maybe they can turn some dogs loose on the
> > captive-bred marmots before releasing them? And
> > dive-bomb them with captive Eagles? Just enough
> > exposure to scare and educate them to natural dangers
> > before releasing them?
> > Condors in California are routinely hazed away from
> > human habitations by workers running at them,
> > screaming and yelling. And near the hacking sites,
> > fake telephone/power poles are placed for perches that
> > are equipped with low-voltage electrical lines and
> > wire 'brushes' to teach the Condors not to perch on
> > real power poles that could kill them.
> >
> > On a related topic:
> > I would like to see statistics on Peregrine Falcon
> > survival and reproductive success for all the
> > individuals released by the Peregrine Foundation as
> > well. I suspect that almost all the Peregrine Falcon
> > recovery in the US was natural recovery. The only
> > statistics I've ever seen to measure the 'success' of
> > the Peregrine Funds release efforts have been the
> > number of birds released. Not the number that
> > survived long enough to reproduce.
> > I bet I get an outraged response to this question ;)
> >
> > Sorry about the long rant. Pushed one of my buttons
> > ;)
> >
> > Guy McWethy
> > Renton, WA
> > mailto: lguy_mcw at yahoo.com
> >
>
>
>