The (paywalled) Philadelphia Inquirer reports on a citizen science bird count showing a massive drop in the pigeon population over the last few years. At the same time, raptor populations like red-tailed hawks and Peregrine falcons are up. There are reasons the data are uncertain, but this is still pretty cool.
I’ve had some memorable raptor sitings in Philly over the years. Recently, I heard a significant commotion and looked up to see a red-tailed hawk in a tree very close to my front door. This was early spring before there were leaves on the trees, so I imagine it had a good line of site to the ground. Mice and rats were the first prey species that popped into my mind, but yeah there are pigeons around too.
Peregrine falcons are not very shy in urban environments. I remember seeing one sitting on a street map above a busy street, next to a park that I know from personal experience is full of mice, rats, and pigeons.
Once I saw a falcon that had trapped a squirrel under a bench in Rittenhouse Square. Like I said, they are not shy around people, but when the park is busy they will tend to be hire up in the trees or on buildings. This was very early in the morning, and the falcon was just sitting there on the bench with the squirrel underneath. The squirrel would try to run out, and the falcon would swoop out and try to get its talons around the squirrel, and the squirrel would slip out and dart back under the bench. Falcons are big birds. I gave this one a respectful distance, but it took no notice of me whatsoever.