Species definitions!

Michael Gochfeld gochfeld at eohsi.rutgers.edu
Thu Sep 6 18:47:55 EDT 2001


Alex, 

I think I understand your point. But as a Cabbage-counter, let me defend
my point. I do regular censuses of butterflies in our yard. The number
of Cabbages (probably the only species that will allow statistical
analysis) varies dramatically from 0 (rarely) to over 100 (rarely),
usually in the 6 to 20 range. 

What governs this variability: 
	year to year variation
	seasonal phenology
	daily cycles
	immediate weather conditions (particularly sunshine and temperature)
	weather the preceeding week, month, or winter (needs too many samples)
	chance

How much variation is there on counts taken 30 min apart, 1 hr, 4 hrs.

I wish I could say that over the 10 years, I have gotten enough
"samples" to address all of these variables.  But it is clearly
interesting. Whether it matters to the Cabbages, or not, I can't say. 

It's not that I care much about Cabbages, but that no other species is
consistent enough to provide the statistical variability to analyze. 
There are other techniques (logistic regression on presence or absence)
that I'll use for other species. 

You will be pleased to know that the number of Uncomphagre Fritillaries
in the yard does not show the same degree of variability (probably for
other reasons). 

Mike Gochfeld
"Grkovich, Alex" wrote:
> 
> No argument, Michael. But when counting numbers becomes the total focus,
> then something is wrong. All summer I have seen countless e-mails of that
> type: endless numbers and numbers. Then I began to ask: "OK, but what
> actually did you see? Did the "Red Spotted Admiral" (Michael, I am dead
> against that name for individuals of the species; I don't mind referring
> that name to the entire species as a whole) you say you saw have blue HW or
> bands, or what % of bands" etc. "Were there any Northern Crescents among the
> 43 Pearl Crescents?" Did any of your 157 Common Wood Nymphs lack orange
> bands? Or were any with yellow bands? Reduced FW eyespot?" etc. etc. etc.
> 
> Unless we're talking about the Uncompaghre Fritillary, it shouldn't make any
> difference as to whether there are 235 or 254 specimens in a large field.
> There should be more important things to focus on.
> 
> Michael, do you not understand what it is that I'm trying to express? Who
> should care whether there are 25 or 35 Cabbages flying around? Klots said
> that his new book "was necessary to reflect the change in our science, that
> it has progressed beyond the rigid  and static, and has become more fluid
> and dynamic" something like that. What I'm seeing is a subtle return to what
> Klots spoke of that had passed.
> 
> > -----Original Message-----
> > From: Michael Gochfeld [SMTP:gochfeld at eohsi.rutgers.edu]
> > Sent: Wednesday, September 05, 2001 9:24 PM
> > To:   agrkovich at tmpeng.com; 'Leps-l'
> > Cc:   'Mark Walker'
> > Subject:      Re: Species definitions!
> >
> > The following is written with subdued tone.  Although I applaud going
> > beyond the
> > numbers to examine ecology, ethology, physiology, morphology and variation
> > etc,
> > I think there is something that must be said in support of numbers, if
> > they are
> > systematically (and more or less accurately) obtained.  "245 X, 126 Y, 57
> > Z
> > when collected over time and space can provide important information about
> > the
> > populations in question.  MIKE GOCHFELD
> >
> > > Oh, I'm not saying the field work is not necessary. Quite the contrary!
> > But
> > > if we observe the countless Fritillaries with the intent of merely
> > drawing
> > > up a tally of "245 X, 126 Y, 57 Z... etc." without progressing beyond
> > this
> > > level of study, then what is the worth of the field work, either to
> > > ourselves or to science? The poor fellow who has taken the time and
> > spent
> > > the energy to determine that there were "223" instead of "225" Juvenal's
> > > Duskywings (and I'm using an example of a posting I saw from this past
> > May-
> > > and the poor fellow reported them as "Juvenile's") himself is probably
> > > unaware of the treasures that exist on the other side of the door of
> > > understanding. That's what I'm talking about. This is why someone taking
> > the
> > > time to count the actual number of Cabbages seems worthless to me while
> > the
> > > person may be at same time being blind to the observation of the degree
> > of
> > > white banding on an astyannax or the degree of hybridization between
> > > weidemeyerii and rubrofasciata etc. etc. Or even to the understanding of
> > why
> > > some astyannax have bands and others don't. And the worst factor is that
> > > some people in leadership capacities permit or even propagate ignorance
> > in
> > > others.
> > >
> > > > -----Original Message-----
> > > > From: Mark Walker [SMTP:MWalker at gensym.com]
> > > > Sent: Wednesday, September 05, 2001 3:15 PM
> > > > To:   'agrkovich at tmpeng.com'; 'Ron Gatrelle'; 'Leps-l'
> > > > Subject:      RE: Species definitions!
> > > >
> > > > Alex wrote:
> > > >
> > > > > I guess what bothers me the most is that such very deep
> > > > > mysteries have been
> > > > > replaced by endless reports of "I saw 23 Orange Sulphurs and 15
> > Common
> > > > > Sulphurs and 223 Juvenals Duskywings and ...." And anyway,
> > > > > since when has it
> > > > > become so important to actually count Cabbage Butterflies????
> > > >
> > > > Ahhh, yes, but I guess it IS more important to encourage field work of
> > any
> > > > sort - even if the notion of counting does seem a bit less interesting
> > > > (not
> > > > to mention accurate) than sampling.  I, for one, would like to know
> > when
> > > > someone sees hordes of Juvenal's Duskywings.  In fact, I'm sorry I
> > don't
> > > > provide more information on frequency in my field posts - I've mostly
> > > > stopped putting comments like 'common' or 'numerous' in them.  A lot
> > of
> > > > this
> > > > information is just as, if not more, important than the fact that the
> > > > species was sighted at all (which I guess is Alex's point anyway - we
> > > > don't
> > > > talk about it like Klots did - at least not much, anymore).  For
> > example,
> > > > on
> > > > my most recent trip (while in Grant, Co. OR), I found lots of
> > > > Fritillaries.
> > > > One of them was Speyeria hydaspe.  All the other species of Speyeria
> > were
> > > > fresh.  Absolutely none of the S. hydaspe were fresh, and in fact
> > there
> > > > were
> > > > few with whole wings at all.  This would tell me that S. hydaspe flies
> > > > quite
> > > > a bit earlier than the other Speyeria (along with S. cybele leto), a
> > > > simple
> > > > enough conclusion - but one of significant interest nonetheless.
> > > >
> > > > Incidentally, I'm looking over the races of Speyeria according to
> > Howe.
> > > > Awesome.  I don't care what you call them specifically, there's little
> > > > more
> > > > fascinating then a drawer showcasing ecologically induced Speyeria
> > > > variation.
> > > >
> > > >
> > > > Mark Walker
> > > > Oceanside, CA
> > >
> > >
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-- 

================================================
Michael Gochfeld, MD, PhD
Professor of Environmental and Community Medicine
UMDNJ-Robert Wood Johnson Medical School and
Environmental and Occupational Health Sciences Institute
170 Frelinghuysen Road
Piscataway, NJ 08854  USA
732-445-0123 X627  fax 732-445-0130

 
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