... Giant Birds.
When I was a kid, I lived about a 15-minute walk from the Delaware. You never saw gulls or terns there. Now, you not only see them there - which is to say all up and down the river, way beyond the bay - but also here in the Italian Market (which isn't very far from the river) and even in suburbs like Abington (which isn't too near the river). Why? Fast-food joints for one. Also, animals are neither as dumb nor as programmed as humans seem to think. Wildlife in the city has less to do with humans destroying the animals' habitat than it does with many animals' discovery that human habitation is safer than the wilderness and has more abundant food. As the owner of an outfitters' store in Potter County (which advertises itself as "God's country"), told me, you can find more bears around Harrisburg than you can in Potter now - you can't hunt outside Harrisburg, and there's lots more garbage.