[Odonata-l] Leg position in windy conditions -- teneral or typical?

Sat Sep 6 12:30:09 PDT 2008

Hi Bob and everyone--

In reply to the clutch/grasp issue--it is one of stability, I think.  At
least, over the years, when I have filmed--and, I have never posed them - or
tried to capture them with a net (not that I disapprove--but my years of
cultural anthropology training have taught me just to observe--not interfere
with the culture), I have always waited for them to come to me in the
particular area I am observing - except I do experiment with calling to
them, talking--AND ESPECIALLY MAKING EYE CONTACT if possible.

It seems to depend, mostly, on the thickness, tensile strength and/ or
diameter of the perch.  But, if they have just rotated their eyes and
cleaned them with their forelegs (that they often rest behind their
head-when feeling (best descriptive word) particularly secure)--they do,
immediately grasp more tightly the perch on which they are grasping.  Wind
is a factor- I have film in which they are grasping tightly while being
blown around quite a bit.

I also have noticed them doing something really funny and "human-like," and
have filmed this behavior often----they seem to get tired of using both
forelegs to support themselves, and rather than put one or both of them
behind their heads--they will pause with one foreleg in a supporting
position, while the other just rests on top of the supporting one.

Another interesting thing I have observed is, in most cases during the day
in their active  cycle, you will seldom see them hanging down from a
branch-underneath it.  That position seems to be almost exclusively for
resting-and almost always at night.  BUT, last year for the first time, at
one time we had a great deal of competition at our site-and it is small-AND-
for the first time, I filmed one of the males using the position
tactically-to remain in somewhat control of the habitat-while other males
and females used the site for reproduction.-------I actually have on
film the dragonfly in his initial upright protective, watching position and
when the others moved into the territory-he changed his position to the less
visible confrontatory position-hanging down from the bottom of the same
branch.

Another video shows a Libellula vibrans hovering under the shadow of a small
bridge to avoid being "attacked" by the dragonflies already in control of
the area---the whole action is quite interesting--BUT what I found MOST
interesting was- you could almost consider the dragonfly a "tool user," by
avoiding conflict, by use of another object.

I hate to refer to my meager website--thanks for the help-I am getting a
camera that I might be able to use to upload some of this newer -MUCH BETTER
stuff-- but in the Infrared album and the Dragonflies etc. album have quite
a few different leg positions-the Dragonflies etc. has the one where the d.
is looking up at me with his one leg resting on the other - its pretty funny
looking.

I think this address might work:
http://www.neptune.com/features/view/framesetview.cfm

I also have really close up- the d. rotating his head almost 360 degrees and
his forelegs cleaning his eyes-yet to be posted--it's amazing the little
barbs on his forelegs don't damage the membrane covering his eyes.

Thanks you guys!

Martha Edwards Smith

On Fri, Sep 5, 2008 at 9:24 AM, Bob Glotzhober
<bglotzhober at ohiohistory.org>wrote:

>  First a brief report, then a question.
>
> Bill Hull of Cincinnati had noted that there were only two records for Ohio
> for the Eastern Ringtail, Erpetogomphus designatus. They dated 1913 from a
> published record by James Hine for Hamilton County (includes Cincinnati),
> and a 1954 specimen at OSU taken by Homer Price in Paulding Co. (extreme NW
> Ohio). Since Bill lives in Hamilton County, and is an excellent field
> biologist who loves a challenge, he decided to spend part of this summer
> taking on the challenge of re-finding this critter. Bill succeeded with that
> at a spot along the Whitewater River in extreme SW Ohio  on August 23rd –
> and got some great photos. He was kind enough to invite me down, and we both
> revisited the site on August 26th. We spent a long, hot day, but finally
> found them again – seeing perhaps half a dozen or more specimens. We each
> got more photos, and I collected a single voucher. I'll leave the details of
> Bill's search and find for him to report some other place and time – maybe
> he'll be willing to write it up for Argia (hint, hint).
>
>
>
> What I am curious about, however, is leg position in perched individuals.
> The photo Bill sent me from the 23rd (a very still morning) shows the
> critter perched on a grass blade in what I would consider a typical,
> 6-footed, spread-leg pattern. One of mine (image 2773) the legs are somewhat
> similar and "typical", although two of the legs are slightly wrapped around
> the blade of grass. On the other two images (2783 and 2791) the legs and
> feet are wrapped around the grass stem or the flower head in clutch-like
> grip which I recall only seeing on captured-posed specimens – i.e. where
> they had stress from cooling or wing-folding techniques to keep them from
> flying for close up photography. That is not the case on any of these images
> – all were taken from free-flying, un-captured specimens.
>
>
>
> The only thing I can think is that this may be a result of the fact that
> these are semi-teneral adults and they were seeking shelter in a little
> hollow in the grassland on a day with an approximately 10 mph breeze. Their
> wings are clearly firm and no longer teneral, but they were clustered
> off-river in a grassland and comparison with colors of other specimens on
> the web suggest their colors are still somewhat paler than normal (or is
> that an eastern variation compared with specimens from further west?). Has
> anyone else observed clutching behavior like this?  i.e. "wrapping your arms
> around a tree trunk so the hurricane does not blow you away" type behavior?
>
>
>
> I'm eager for any thoughts or observations list members might share.
>
>
>
> Bob G.
>
>
>
> ====================
>
> Robert C. Glotzhober             614/ 298-2054
>
> Senior Curator, Natural History         bglotzhober at ohiohistory.org
>
> Ohio Historical Society         Fax: 614/ 297-2546
>
> 1982 Velma Avenue
>
> Columbus, Ohio  43211-2497
>
>
>
> Visit the website of the Ohio Historical Society at:
>
>   www.ohiohistory.org and check out our online collections catalog.
>
> See or purchase Dragonflies and Damselflies of Ohio or the Cedar Bog
> Symposium II at OHS's new E-Store:  http://www.ohiohistorystore.com/
>
> Visit the Ohio Odonata website at:
> http://www.marietta.edu/~odonata/index.html
>
>
>
>
>
>
>
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