In the Okanagan Valley north of the USA/Canada border the Turkey vulture had all but dissapeared in the 1960's . They now have made a huge comeback and we now have about 50 pairs near here. While they are ugly as all get out up close, they are the most magnificent fliers of all. I watched two eagles ride a thermal for about 20 minutes upwards till they were just specks in the sky. along came 4 turkey vultures who rode the same thermals and in 5 minutes they were out of sight. I thought wow they must be lighter than the eagles with the same wing spread. I figured that they probably were just good soarers and not so good near the ground. Wrong! one day we watched one swoop down to elude a smaller bird that was harassing it. It zig zagged thru a grove of some small closely growing trembling aspens that caused the small bird to give up the chase. Its dexterity was amazing to watch.