I will not get involved in this discussion
...
I will not get involved in this discussion
...
I will not get involved in this discussion

On Thu, 2006-09-07 at 11:22 -0400, Bell, Tyler wrote:

> The example of the Peregrine Falcon is quite apt. I would wager that in
> years to come that there will be little argument about the validity of
> Trumpeter Swans in the Chesapeake Bay area. Let's hope anyway!

Sigh.  It worked for a few days.

Hope is such a word.  All we need is yet another *non-migratory*,
*large* swan hanging around the Chesapeake Bay destroying the ecosystem
by eating all the SAV.  When are we ever going to learn.

And don't start claiming that this is a *re*-introduction.  There is no
evidence that these swans *regularly* wintered in the Maryland portion
of the bay.  There inclusion as historical on the Maryland list comes
from a record on the Potomac River and although it was accepted, (if my
memory is correct and I'm too lazy to check the facts) there was some
dispute about whether that record referred to Maryland waters or the
Occoquan Bay, which is in Virginia.  Regardless of whether that record
is valid, Trumpeter Swans probably did visit Maryland on occasion but it
is certain that they were never common and we should pray it stays that
way.

In historic days, the few Trumpeter Swans that came here were migratory,
returning to northern climes during that time of year when the bay
ecosystem is most susceptible to damage by a large grazer.  That's the
main reason why Tundra Swans do not present an environmental problem
while Mute Swans do.

The Eastern population of Trumpeter Swans *is* extinct.  Period.  They
cannot be reintroduced.  There is a western population of Trumpeter
Swans.  I don't know how similar the eastern birds were to the western
birds which are now being introduced in the East and we don't know if
these introduced birds will *ever* set up migratory patterns similar to
the swans of historic times.  Unfortunately, based on the two records
being discussed, these Trumpeter Swans do not seem to have this
migration thing worked out quite right.  Perhaps the western birds
migrate only because the habitat they spend the winter in is unsuitable
for summer and the habitat they summer in is unsuitable for wintering.
The Chesapeake Bay region seems to be good for both.  The scenario is
scary enough to make me think about having two swans for Thanksgiving
dinner.

Now, since I'm on a roll, regarding countability.  You can do whatever
you want but Edward Boyd quoted the ABA rules

> > (iv) An indigenous species which is reintroduced into an
> > historic range of the species may be counted when the population meets
> > the ABA Checklist's definition of being established or when it is not
> > possible to reasonably separate the reintroduced individuals from naturally
> > occurring individuals.

We loose on both counts.  1) A Trumpeter Swan in Maryland will *always*
be a bird from the introduced population so unlike Peregrines, the
population is not countable until the Ontario birds are established.
And 2) introduced birds are not established until they have been
successfully breeding in the wild and sustaining their population for
something like 25 YEARS and we aren't there yet.  25 years seems like a
long time but it is probably too short.  Many introduced species seem to
thrive for that long or longer and then suddenly die out.  If you want
to follow the ABA rules -- and the Maryland records committee had better
do that -- the case is pretty cut and dry; these birds are not countable
(but they're worth seeing anyway).  The situation is more like the
California Condors in Arizona which are not yet countable despite their
successful breeding.

I should not have gotten involved in this discussion
...
I should not have gotten involved in this discussion
...
I should not have gotten involved in this discussion
...

Dave
-- 
David Mozurkewich
Seabrook, PG MD
mozurk at bell atlantic dot net