Walking between buildings on campus today, the squawking of several crows in a large tree, already being observed by two other people, gave me a reason to stop and investigate as well. It turns out there was a large hawk on one of the branches, and according to the other bystanders, it had been chased by the crows into the tree shortly before they stopped to check it out. It was amazing. I'd guess its size to have been roughly 18" tall. I watched for several minutes while other's came to do the same, and one of the bystanders indicated that the hawk has actually been on campus for a couple of weeks, flying between two trees, upsetting the crows and living off the land.
Which explains the recent absence of squirrels running around the grounds.
As I walked away, it flew low across the campus, chased by the crows, and into a tree near the cafe. It was a spectacular sight.
A Side Thought: Having once had a ground floor window office by a tree, I had a front row seat to the activities of the squirrel population. Every time I see the squirrels, I can't help but think of the character Milton, in the film Office Space, muttering about having his desk moved and making a veiled reference to mating squirrels.
"I, I don't care if they, if they lay me off either, because I, I told Bill that if he moves my desk one more time, then, then I'm quitting. I'm going to quit. And I told Dom too because they've moved my desk four times. I used to be by the window, where I could see the squirrels, and they were married."