[Odonata-l] Princely posture

[Joshua Rose]

Howdy folks,

A friend recently asked me about the Prince Baskettail (Epitheca  
princeps) and its habit of perching with its abdomen curled upwards.  
For example:

http://www.giffbeaton.com/Dragonflies/Prince%20Baskettail2_2003-05-14.jpg

My friend has seen the species perched three times, and every time it  
curled its tail like this. The majority, or at least a large  
proportion, of the photos I am finding on-line are as well.

How frequently does this species perch this way, as opposed to with  
its abdomen straight?

Does anyone know a reason for it?

Is this behavior specific to E. princeps, or do other species do this  
as well? I do not recall seeing this in E. cynosura. Cordulia  
shurtleffi, or the other members of the family I have seen perched....

Any information would be appreciated.

Cheers,

Josh