Don Burggraf in a comment today describes a Red-shouldered Hawk on a hot 
day with it wings open and wonders if the bird was doing this to cool itself. 
Large birds roosting with wings akimbo –this may not be quite the right word- 
are not unusual. In June off Hunting Quarter road I watched one of the 
summer resident Yellow-crowned Herons on a low branch taking such a 
position among others over a period of time. I have nice photographs of this. 
The day was not particularly hot. In mid-July I watched an immature Great 
Blue Heron with open wings high in a tree bordering the southeast edge of the 
Hughes Hollow east impoundment. As I watched through a scope the bird 
appeared to be panting- if a bird can pant. The temperature was in the 80s 
and the bird was shaded in the tree branches. Of course we see Anhingas 
doing this so as to dry out their wettable feather after a swim and I have 
often seen Turkey Vultures doing this roosting in the Sun.  Turkey Vultures . 
I’ve always thought they rid themselves of parasites this way.  So there may 
be a number of reasons for these poses. The Yellow-crowned Night Heron I 
thought was incredibly bored and so was posing. First side view, then with 
back toward the photographer and head twisted forward, then with wings 
akimbo……. 

Phil Brody