I saw movement in the weeds and tried to see what bird was foraging. Wait a minute. That's no bird! That's not even a squirrel. That's an oh-my-God-rabbit!! Chomp, chomp, chomp.
Most likely somebody abandoned a pet in the park. Rabbits are sweet pets, but they poop a lot and if not in a cage at home you can end up with a droppings carpet.