Size Comparison

Photo taken at Laguna Seca Ranch in South Texas last week.

Nikon D810, 300mm lens, 1.4 TC, 1/800 sec at f/10, ISO 500, Full-frame shot.

This shows the size difference between a Turkey Vulture and a young Caracara.  It's unusual for the Turkey Vulture to spread it's wings while a Caracara is on the perch.  There's lots of ideas why the Turkey Vulture spreads its wings facing the Sun.  The best (and real) reason that I have been told is that because Turkey Vultures eat dead and rotted meats, mites get on their feathers.  By spreading their wings toward the Sun, the Sun's rays helps kill the mites.  Also, the white on the back of the Turkey Vulture is where it was "pooped" on by other Turkey Vultures while they were sleeping in a tree at night.  This would mean that this Vulture is one of the lowest on the pecking order.  The dominant Turkey Vultures would sleep higher in the tree. 

The expanded version shows better details.