It's a bird, it's a plane... well, it's a bird, a Cooper's Hawk. There are several active nests in Sabino Canyon. As you are walking along the road (the only place you are allowed to walk, run, or cycle until further notice), keep your eyes open for these hawks. If you are even remotely interested in learning more about these and other birds, I recommend the All About Birds site. And if you like taxonomy (and you know you do), Kingdom: Animalia, Phylum: Chordata, Class Aves, Order: Falconiformes, Family: Accipitridae, Genus + Species: Accipiter cooperii.