> Hellbenders are large, long-lived (possibly 30 yrs), slow-maturing
(probably
> 5-6 yrs) animals with small home ranges, limited dispersal capabilities,
and
> substantial genetic differences between-populations.
Yes, they are large, can live longer than 50 years (every fire slamander can
as well, recorded up to 52 years in captivity). Compared to human
aging-potential and maturing they4re fast! Limited dispersal information is
limited itself as hardly anybody has really studied if and how far the can
migrate. The genetic differences even between the two subspecies are not
substantial (if I interpreted available literature correctly). The latter
would make it easier replacing specimen/transferring to nearby populations.
> Capacity for
> short-term recovery to reductions in population size (via rapid
recruitment)
I don4t agree to that. As far as known only one males reproduces in a season
meaning only one nest is built within a certain segment of the stream.
Several females can take part and supposingly even other males if they are
fast enough (we know this from community spaws in fish). By this,
reproduction rate is limited by the species itself. Putatively caused by the
longevity of the hellbender. Despite of that the number of eggs/larvae is
high but losses as well. From this it could be taken that the surplus
non-reproducing males are just a backup in case the number one male
disappeares. So there is the potential to replace a certain amount of losses
as the offspring wouldn4t have a chance to reproduce until the old
generation will be gone. One could even state that a certain take of old
adults could lead to a refreshing of the populations vitality by opening the
port for younger males and females. If there are let4s say 100 hellbenders
in a stream segment and only one male and some more females reproduce, how
many would reproduce the following year if two pairs were taken? I am
convinced the reproduction rate won4t drop but rather rise. This could as
well be an advantage for the species if the very old generation is
verticutated. What are the natural predators upon hellbenders? Are they
still there or already diminuated? If natural predation is cut a population
and consequently a species may suffer from it by over-aging. That4s one main
reason to hunt deer as there are not enough wolfes.
> and long-term recovery to reductions in range (via rapid re-colonization)
is
> limited.
This is highly speculation as nobody knows about the migration of
hellbenders. And how could they recover range when the range is limited more
and more. Here the dog catches its tail.
> Efforts at captive propagation are planned or are already
> initiated by various groups of biologists at zoos/aquaria and resource
> agencies.
Yes, and fine. There are successes at Mammoth Spring hatchery reported for
the Ozark Hellbender. I don4t know any for the nominate species. But this is
surely in progress and I would like to take part in it.
> How, then, can the removal of any number of hellbenders from any population
> by or for private individuals be justified ?
By exactly that you mentioned above.
> Wouldn't this specific thread (on hellbenders) be more appropriate (and
more
> authoritatively addressed) on the Partners in Amphibian and Reptile
> Conservation list ?
Yes, it came up to more than I expected. But the topic in general is the
same as for many NANF.
Steffen
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