Posted on June 29, 2015
The Blue Dasher is a Great Example of a species of Dragonfly that uses the Obelisk Posture. The Blue Dasher is only about an inch and a half (1.5″) in length. So they are one of the smaller Dragonfly subjects to photograph. Following is information I found on this Dragonfly Posture or Position:
The obelisk is a handstand-like position that some dragonflies and damselflies use to prevent overheating on sunny days. The abdomen is raised until its tip points at the sun, minimizing the surface area exposed to solar radiation. When the sun is close to directly overhead, the vertical alignment of the dragonflies body suggests an obelisk.
Dragonflies may also raise their abdomens for other reasons. Male Blue Dashers assume an obelisk-like posture while guarding their territories or during conflicts with other males, displaying the blue pruinescence on their abdomens to best advantage. Both females and males will raise their abdomens at high temperature and lower them again if shaded.
The obelisk posture has been observed in about 30 species in the Demoiselle, Clubtail and Skimmer families. They are “perchers” — sit-and-wait predators that fly up from a perch to take prey and perch again to eat it. Since they spend most of their time stationary, perchers have the most opportunity to thermoregulate by adjusting their positions.