"tobin" tale

John Grehan jrg13 at PSU.EDU
Thu Jan 7 20:48:31 CST 1999

>Consider this: while scientists may have concluded that the hybrid
>represented un unpredictable potential threat to either or both parent
>species (not an unreasonable conclusion, since there *are* species that
>have suffered from hybridization - genetic purity aside, there's also the
>possibility of mating interference and/or ecological competition, which one
>would expect the scientists also took into account),

None of these issues appear to have been evaluated, or even the
converse that some hybrid introgression may have been "good"
in some way for the survivial of the combined lineages.

why do you *assume*
>that it was these same scientists who decided to kill the hybrids, rather
>than some administrator(s) whose job was to act on the scientists' reports?

I would have to admit that possibility as I have been unable to obtain the
information necessary to know. I have made an assumption that may not
be correct.

>This would seem more in keeping with how the real world operates
>(scientists make recommendations, but administrators make *policy*),

If I understand the institutional infrastructure the people who are
administrators are themselves people with formal scientific

>        Besides which, it would not really be hard to argue that this was
>essentially the only approach that *guaranteed* that the hybrid(s) would
>not pose a threat to the continued existence of the parent species.

Trouble with this particular situation is that there was no scientific
argument presented to support the proposition that there was
any real threat as such. About 10% of all bird species are known
to hybridize, and then of course there is the question as to whether
such hybridizing entities are really different "species" (yes its
possible that they are, but again no scientific case was made).

>enough ecological disasters under our collective belts, maybe this is just
>a sign that some people are trying to think proactively and avoid problems
>before they have a chance to start.

In this case the only defined "problem" has been of an ideological nature (a
supposed purity as the ideal of a species). It may well be that there is
 a good scientific reason to avoid further
hybridization, but there appears to have been no effort to make the
case. Any why shoot the bird. It could just as well have been removed
from the island and kept in a zoo for example.

 It notably comes as no surprise that
>this would occur in New Zealand, the place with the most proactive
>"anti-exotic species" policy in the world (instead of a "black list" of
>banned species, they have a "white list" of *acceptable* species, and
>everything NOT on the list is banned).

This might be true, but policy has been poor in the past at least when
involving intorduction of biological controls without adequate
testing of their potential non-target impact.

In summary, I understand the sentiments expressed by Doug
Yanega, and some of his points have relevance, so much so that
its a shame that they were never addressed by the agency in question either
before or after the events). The situation appears to be one in
which decisions were
made without scientific rigour. I feel that if decisions are going to be
made about killing hybrids (or any biotic component) it is not
unreasonable to expect an open (pubic) scientific case to be made
so decisions are subject to peer review and critique. Instead the
opposite happened, and most people (involved with the
issue in New Zealand) are apparently happy that these conditions of
secrecy are appropriate for conservation biology.


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