floating on water surface

Dennis Paulson dpaulson@ups.edu
Thu, 20 Jan 2000 08:20:39 -0800

Odonata - http://www.listbot.com/cgi-bin/subscriber

Kelvin Conrad wrote:

>The fact that the 'display' is not frequent or widespread suggests it may
>not have an adaptive function at all.

I liked your explanations, Kelvin.  If we can anthropomorphize mammals, why
not odonates!

But I'll add that I wonder if the reason we don't consider a display
frequent or widespread is just because we're not spending enough time
watching odonates, as was said earlier.  When I'm on an "expedition" in
some part of the world, I'm trying to sample/survey biodiversity in an area
that I haven't previously visited, and my main goal is to see how many
species are at a particular pond or stream and what they are.  Thus I spend
precious little time just sitting and watching a single species.  Trying to
get good photographs of perhaps never-before-photographed species takes up
more of my time.  I really wanted to study the behavior of several genera
of damselflies on my last trip to Australia, and I found it frustrating to
sit there for a half an hour watching a male do essentially nothing, when I
could be walking farther down the stream and finding additional species.
So with some negative reinforcement and very limited time, I slacked off on
the behavior study.

When I lived in Costa Rica, I visited the same "exotic" places over and
over again, was satisfied that I had surveyed them adequately, and had time
to sit and watch odonates.  I learned so much about tropical odonate
behavior when I took the time to do so.  I saw aggressive and courtship
displays infrequently, even then, but I was convinced they were bona fide
displays (i.e., adaptations), not occasional random behavior.  I wonder if
our lack of observations of some of these behaviors aren't just indications
that none of us - collectors, photographers, or observers - spend
sufficient time with a single species necessary to determine the frequency
of some less common behaviors.  I acknowledge that you did study Calopteryx
aequabilis behavior, so presumably you *do* have a good idea of this.

A student of mine, Greg O'Neill, tried to study the behavior of Phaon
iridipennis in Ghana.  He dutifully caught and marked a bunch of males and
then was frustrated because many of them didn't do much of anything, only
the occasional foraging flight.  His other project was a biodiversity
study, and that turned out to be so much more productive, because
everywhere he went and everything he saw added to it.

We should proclaim one week next summer Calopteryx Week, during which
everyone would go out and spend an entire day watching the Calopteryx
species of their area.  Or a Calopterygid Week, for those people who don't
live in the range of Calopteryx.  Or a Classy Zygopteran Week, to include
the Australians.

Dennis Paulson, Director                           phone 253-756-3798
Slater Museum of Natural History                 fax 253-756-3352
University of Puget Sound                       e-mail dpaulson@ups.edu
Tacoma, WA 98416

Status: N