Tucson sightings

[Mark Walker]

Hmmmm.  While I would agree that the "count" is both misrepresentative and
potentially misleading, I would argue that once again a little data is
better than too much filtering.  In science it should be clear that
observation tells only part of the story.  When Bill reports seeing 25
Snouts and only one Pima Orangetip, that tells me lots of things:  First,
there are a good number of leps on the wing.  He didn't have to turn over
every stone to find bugs flying.  Second, it tells me that the Snouts were
of the most abundant - which tells me something about what's going on in SE
AZ (as well as where each of the bugs are in their relative emergence).  For
example, it tells me that the Pima's probably haven't yet exploded - which
I'm always interested in knowing.

When I used to include counts in my field reports, I would usually focus on
integers for those species that were less common - and indicate something
like 25+ to indicate abundance.  Now it should be obvious that 1 sighting
for Erora laeta, for example, doesn't imply that there must only be a single
individual in the entire region.  Instead, it implies that the bug is
present but not likely to be seen (as usual).  If instead there are 10 E.
laeta sighted (like there was in a post from Massachusetts a few years ago),
that tells me that the species is likely peaking, and that the observer has
stumbled on a healthy colony.  There's a lot of good data there!  

I personally treat this type of counting as a statistical sample - and my
guess is that the representations would hold statistically if I were to
conduct my own sampling at the same location.  So - when I do sample, and
the statistics are different - that's important data as well.

Now, if exact counts are not useful then we should come up with another way
of indicating quantity that is more acceptable.  Leaving the notion of
abundance off of a field report (which I usually do these days) is equally
misrepresentative.  I'm just too lazy to write it all down - and so the data
is less useful.

At the end of the day, we should do nothing to discourage the posting of
field data.  While it may be of limited interest to many, there is a large
network of mostly silent "listeners" out there who care about what is flying
and where.  If I may speak on behalf of those, I would like to encourage
more posts like that of Bill's - especially in mid-February!

Mark Walker
back from snowy Castleton, Vermont. 

> -----Original Message-----
> From: Ron Gatrelle [mailto:gatrelle at tils-ttr.org]
> Sent: Tuesday, February 20, 2001 8:14 PM
> To: bmw60 at aol.com; Leps-l
> Subject: Re: Tucson sightings
> 
> 
> Editorial
> In the old days, before butterflies became birds, we never thought of
> "counting" specimens. Yes, one might note a single specimen 
> of this and
> that or two or three. Beyond that, counting can become 
> absurdly inaccurate.
> I have many years of experience in the field in all sorts of 
> habitat with
> all degrees of abundance of specimens. One A. pima, 3 
> mexicanum, yes I buy
> that. 25 snouts, no way. 24 with one twice, 15 with x twice, 
> xx three times
> etc. Or, 25 seen with another 25 in the direction one was not looking.
> 
> How about 500 Satyrium calanus flying with another 25,000 E. favonius,
> 3,000 A. halesus, 11,000 cecrops, 200 sweadneri, + 200,000 assorted
> skippers of various species and all along the Istachatta RR track in
> Florida - I've been there and defy anyone (other than God) to give a
> "count" of what was flying.
>
> How about getting a number in western North Carolina in the 
> spring when the
> Erynnis emerge. E. icelus, brizo, zarucco, juvenalis, 
> horatius, martialis,
> and baptisiae are all flying together in swarms. Colias in an 
> Iowa alfafa
> field. Erora laeta at Big Black Mtn Ky or Jones knob SC - 98% of the
> population won't even be seen.
> 
> It is a shame that the area surveyed below was completely 
> devoid of moths -
> as none were "counted" . Hundreds if not thousands of them 
> were roosting
> about. Does a no count mean not present?
> 
> Then there is this 4th of July thing. Maybe that works for 
> birds everywhere
> and butterflies in New York.  I don't even collect here in SC in July
> because about all that is out is junk - carp and sparrows. 
> Spring and fall
> are the time to find stuff - especially for the hairstreaks 
> and skippers.
> June can be good in the mtns. The only things I'd go to the 
> mtns for in
> July would be S. diana and P. faunus smythi. Everything else 
> is pre July.
> 
> Bill, this post is not dirrected at you. It is directed at an 
> activity that
> I consider rediculous - butterfly "individual" counts. (Hate mail
> expected.) In the old days we lepidopterists would relay 
> field information
> as follows: Observed 2 X,  4 Y's, several Z's,  G was common, 
> and H, I, B
> and Q were abundant. We knew what that meant. Further, what 
> we Easterner's
> called abundant was the equivalent of common to western collectors.
> Abundant in western terms was a "population explosion" back east.
> 
> Species lists like the one Bill provides below are needed. A 
> count (vs.
> estimate) on the other hand leads to the idea that that is "all"  the
> adults at a particular time and site. This works for birds - but not
> insects.  It is alarming for a birder turned butterfly 
> watcher to hear of a
> collector having caught 600 Speyeria one day in Utah, or 
> 1,000 favonius at
> one stop in Fla. 600 or 1000 birds is a huge number, but with 
> insects it is
> often not even a drop in the bucket.  I have been places 
> right here in the
> SE US where the total number of specimens in a few acres (for 
> all species)
> was in the millions.
> 
> Which brings me to my last point. Perhaps things have gotten 
> so bad in the
> Northeastern US, in particular, that populations are now so 
> depleted by
> habitat destruction that 35 P. rapae is considered a "big" number. If
> things were like they "used to be" lepsters would not even attempt to
> "count" individuals. In this light, countability is 
> indicative of only one
> thing - an environment in crisis.
> 
> Ron
> 
> ----- Original Message -----
> From: "BMW60" <bmw60 at aol.com>
> To: <leps-l at lists.yale.edu>
> Sent: Tuesday, February 20, 2001 8:02 PM
> Subject: Tucson sightings
> 
> 
> > I took a hike yesterday (19 Feb), up Fingerrock Trailhead.  
> The weather
> was 74
> > degrees, clear as a bell and a trace of a breeze.  Perfect.  What a
> difference
> > a few good days in a row make.  Unlike the hard freeze near Willcox
> Arizona I
> > subjected myself to on my annual Javelina hunt.  (Collared 
> Peccary).  The
> > following is a list of species observed;
> > Sisymbrii White--Pieris sisymbrii---4 Specimens
> > Anthocharis pima--Desert Orange-tip---1
> > Anthocharis sara--Sara Orange-tip---20
> > Colias philodice--Clouded Sulpher---6
> > Colias zerene--Southern Dogface---5
> > Libytheana bachmanii--Snout---25
> > Agraulis vanillae--Gulf Fritillary---1
> > Vanessa atalanta--Red Admiral---1
> > Asterocampa leilia--Empress leilia---10
> > Leptotes marina--Marina Blue---5
> > Eurema mexicanum--Mexican Sulpher---3
> >
> > Systasea pulverulenta--Arizona Powdered Skipper---25
> > Copaeodes minimus--Minimus Skipperling
> > Unidentified Duskywing---3
> >
> > All in all, pretty good.  I did manage to catch one of the Sisymbrii
> Whites in
> > my straw hat.  You do what ya gotta do.  See ya,  Bill
> >
> >
> >
> >  ------------------------------------------------------------
> >
> >    For subscription and related information about LEPS-L visit:
> >
> >    http://www.peabody.yale.edu/other/lepsl
> >
> >
> 
> 
>  
>  ------------------------------------------------------------ 
> 
>    For subscription and related information about LEPS-L visit:
> 
>    http://www.peabody.yale.edu/other/lepsl 
>  
> 

 
 ------------------------------------------------------------ 

   For subscription and related information about LEPS-L visit:

   http://www.peabody.yale.edu/other/lepsl