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on 11/21/02 4:13 PM, tom curtis at [log in to unmask] wrote:

> I might point out that this could all be academic.  If the bird needs to be
> captured to positively identify it, one might not be able to count it on
> his/her list anyway.  If I recall the rules accurately, the lister must
> make the ID, not be told what the animal is after the fact.  As an example,
> on the Missouri list a couple of years ago, someone posed the question "If
> you see a bird that you ID as a [FILL IN THE BLANK] flycatcher, and then
> it's netted and ID'ed as a Nutting's Flycatcher, can you count it on your
> list?".  You did not actually properly ID it yourself, but you did see the
> bird that was later positively ID'ed.  What do you do?

I think the key point here is that the lister personally must observe
characters sufficient for identification.  The bird neednıt be identified in
the field to be listed, as long as the lister personally observed the
critical character(s).  In the flycatcher example above, if the would-be
lister did not actually see the critical character that allowed the bird to
be IDed in hand, she canıt count it   If she did observe the character but
was unaware of its ID significance at the time, she can still count the
bird.

> In the case of the
> swallow, if it needs to be verified in hand, can anyone really say that
> they positively ID'ed it?  Without capture, it might never be positively
> ID'ed.

At Viera yesterday I saw a *Tachycineta* swallow with a completely white
rump.  I did not see the supercilia or white-edged tertials.  Will I be able
to count the bird, assuming that it eventually is positively IDed?  I think
so, even if distinguishing between White-rumped and Mangrove relies on
characters I did not observe

When we attempt to identify any unfamiliar bird, we quite reasonably
restrict the possible suspects to species known to occur at or near our
location (as do field guide authors who seek to furnish us with info to make
ID calls).  If you saw a swallow with an entirely white rump like this in
Mexico, you would reasonably ID it as a Mangrove Swallow, as no other
swallows that occur there have entirely white rumps; you would not worry
about White-rumped (nor do Howell & Webb in their Mexican guide).

When (if?) the Viera swallow becomes identified positively, it will be added
to the list of species known to occur at Viera*, and I will recognize that
species as the one I saw at Viera, because I observed a character that
allows me to distinguish that species from all other swallows that occur
there -- the white rump.  I wonıt have to worry about the other current
contender, because it has never occurred here

At any rate, thatıs my story and Iım sticking to it.

David Wright
Miami Shores

*Obviously if another white-rumped (lowercase) swallow shows up at Viera
next year, we will not be able to assume that is the same species as this
year... faunal lists, are time-specific, after all (e.g., a bird list for
Viera in the Miocene would include some interesting species not found there
today).

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