Kevin is concerned about what will happen to the pigeon. The pigeon is undoubtedly a homing pigeon that's gone astray. As mentioned here a few columns back, if you can get a look at the numbers on the bands, you may be able to track down the owner. Hummingbirds sense when it's time to leave. They won't hang around just because there's still food and the weather's warm.
Migration is triggered by the length of the day, possibly also the angle of the sun.
These will probably include red-tailed hawk, American kestrel and barn owl. The Connecticut Rare Bird Alert reports that At the Quaker Ridge hawkwatch at Greenwich Audubon, a variety of raptors were tallied during the past week including bald eagle, northern goshawk, numbers of broad-winged hawks, peregrine falcon and merlin. An early Lincoln's sparrow was there on Sept. 4. Another early Lincoln's sparrow was at the farm fields at Crook Horn Road in Southbury on Sept. 7. Also early were six ring-necked ducks on Laurel Reservoir in Stamford on Sept. 7.