x2, we do the same around here! November marks lock down for my typically free range flock. I had hoped to make it until the end of November, but had my pine tree roosting cockerels taken at dawn last Sunday by a 4 legged predator. I slept in, so I had not yet let the entire flock out. Good thing, too, or I would have been down some laying hens no doubt.
No avoiding it this time of year. The hawk you saw today may be a totally different one tomorrow.
http://www.hawkmountain.org/raptorpedia/migration-path/page.aspx?id=352
Our rule of thumb since having chickens is lock down from the time all the leaves are gone (Nov) through whenever leaves show back up again. Predators can hit any time of year, but I take the chance. Our chickens are locked tight at night, and have a "chicken proof" run during the day. It is mostly solid, but is covered by bird netting on the top (which can be found cheap at Lowes) to deter hawks. No issues in 2 years with hawks getting into the run.
