What type of dragonfly is this and what why was it arching it's back? This was taken in SE Massachusetts. Thanks!
CLOSED: Gymnastic Dragonfly
This is one of the pennants in the genus Celithemis; possibly the calico pennant, Celithemis elisa - http://www.thehibbitts.net/troy/photo/odonata/calico.pennant.c.elisa.tx.liberty.09.3a.jpg
Unfortunately, I cannot provide a reason for its pose.
I think Calico Pennant is the proper ID. Thanks for the help. :)
I have taken another look at this image, and now believe that I was mistaken in calling it a pennant; it more likely is a female eastern amberwing, Perithemis tenera - http://www.dragonhunter.net/perithemis_tenera_f.jpg
And I have found out that the pose is called "obelisking" - http://home.earthlink.net/~twhelanb/images/diary/obelisking.htm
Wow, I'm glad i checked back to this post. Obelisking to stay cool. It was hot as hell that day so that makes sense. Thanks!