I was out late this afternoon trying to take photos of a verdin that kept hiding in the palo verde branches, when I saw a large shadow. I swung round and took a photo as a turkey vulture flew behind the tree.
The turkey vulture, Cathartes aura, is a large bird, about 25-32 inches (64-81 cm) in length, with a 67-70 inches (170-178 cm) wing span. It feeds on carrion, using its sense of smell to locate its food. It has a heightened sense of smell that allows it to find carrion even underneath a forest canopy. The turkey vulture breeds in summer from southern Canada through the United states and southward. They are not found in the Great Plains. In winter, it stays in northern California, Mexican border, eastern Texas, southern Missouri, and southern New York southward throughout the southeastern United States and south.
The Turkey Vulture maintains stability and lift at low altitudes by holding its wings up in a slight dihedral (V-shape) and teetering from side to side while flying. It soars for long periods, and flaps its wings infrequently and slowly.
I tried to get photos of the turkey vulture as it soared above me. I found manually focusing on it was difficult. There was enough variation in distance that I had to continually focus, and the vulture wasn't far enough away for me to focus at infinity. Auto-focus wouldn't work because the camera couldn't find anything to focus on.
We see turkey vultures quite frequently. Usually I see one, or perhaps two, at a time. However, on cold mornings I look up to see as many as forty spiraling in a group slowly rising higher and higher. I was told that they do this to warm up their wings before they start soaring.