While I dont think its the main factor, I certainly think it plays a role. IMO, the only constant is photoperiod in the deers life cycle. Which is why in any given region you will have certain times when things will be happening affecting animals in that particualr region. November always has rutting bucks, september always has rutting bulls. A couple weeks this way or that way, can be swayed by so many factors it makes my head spin, but is alot of fun to think about.