Outside his office window Nate witnessed a large hawk grab a bird, leaving no evidence other than an explosion of feathers. He ran to get me and other interested onlookers, and together we watched a Red-tailed Hawk holding a medium-sized gray bird in its talons while perched in one of the courtyard sycamores. Disturbed by our movements the hawk flew off and may have actually collided with our infamous corridor windows, causing it to release its prey. It dropped down to collect the bird then flapped out of sight over the building. We followed its flight path but were unable to locate our raptor again.
Out in the courtyard I found enough feathers to be able to identify the prey as a Mourning Dove.
Mourning Dove, Zenaida macroura, brown wing feathers and the white are tail feathers
Some information about the Red-tailed Hawk from Cornell University's Birds of North America Online:
The species is primarily a sit-and-wait predator and generally requires elevated perch sites for hunting. The species’ diet includes a wide variety of small to medium-sized mammals, birds, reptiles, amphibians, arthropods, and fresh carrion.
Here on campus, we've seen our Red-tails perched in the tall spruce tree in the A-21 parking lot, in tall deciduous trees around the borders of the parking lots and sometimes on the edge of the roof.