ORIGINAL: Robert Rowland
They could both be onto something. Maybe the rut trigger is a combination of photo cycle and moon phase. Ask any paramedic and he will tell you that the moon phase causes lots of things to happen. Maybe the photo cycle sets the mood, and the moon pulls the trigger.
I tend to agree with this but my overall opinion on the topic is very similiar to CA except for the actual dates.
I believe photperiod in the fall along with the new moon of September(when it falls late like this year 9-29-2008) or the new moon in October(when it falls early like last year 10-11 2007), are the two thing that trigger a does 30 day estrous cycle and start ratcheting up bucks testosterone levels.
The thing that isn't convincing to me about the trigger just being photoperiod is how photoperiod actually takes place. Yes the amount of light gets shorter but we are talking about a minute or two each day, to me that doesn't seem like much of a stimulous but I do fell it helps gets the deer started.
This is the part where I tend to agree with CA about a more significant trigger being involved and he often mentions the second full moon or the "Rutting Moon" as some call it, I feel like the new moon has a bigger effect and he eludes to something similiar in his studies regarding third quarter changes in deer hormones. Some new studies have shown that the amount of melatonin produced by the pineal gland can be cut by over 50% on bright nights(before, during, and after full moon) and even though photoperiod may have started estous cycles those bright nights around the rutting moon could cause a lull or slow the pace of the cycle a little imo until a little later in the month.
Which brings us to the new moon which is two weeks later in the month, I believe the second new moon and the days preceding and following it(about Oct 25-Oct 31 this year) serve as the kickstart to the real action. These nights are very dark and cause spikes in melatonin output from the pineal glands in both bucks and does which I believe triggers higher testosterone level in bucks heightening their sexual aggression and triggers a does actual "heat cycle" which is the last 7 days of her full estrous cycle which is what I was talking about earlier being cued by photoperiod and the dark nights around Septembers new moon, Sept. 29. Ive read that only the final 1 or 2 days of those last 7 days is when the doe is receptive to breeding.
The actual breeding part of the rut will be about 7 days later than the time frame of Oct 24-Nov. 5 which is a few days before Octobers late new moon and a few days after. (So roughly Nov.1 -12) <<< Shocking I know.