(I'm lifting the roof on their house) (there are five there, they're all sitting on top of the one broody hen that never leaves that box)
We've got hawthorn trees at the house which are unusual for Seattle (they don't belong here). In the fall/winter the leaves drop and they are covered in berries which are inedible to humans but are apparently like ambrosia to birds and squirrels. We get incursions from neighboring squirrels that the resident ones have to fend off with much shrieking, and of course lots of little birds come through in packs, which seems to be attracting the predator.
I was a bit worried that our cats would take advantage of this bountiful hunting ground (it's really perverse when people with cats set up bird feeders, and having super-delicious trees is not much removed from that), but so far that hasn't really happened.