Something that has me baffled is....
If the rut timing is based on the amount of sunlight at a certain time of the year how does a balanced sex ratio herd with a good percentage of the bucks being mature animals advance the rut timing by as much as 2 weeks? That herd dynmamic can't advance or decrease the available sunlight.

And only mature deer emit these pheromones/hormones?

It is surmised that the reason buck age structure plays no role in rut timing in the North is because rut timing there is so critical for offspring survival. In essence, the need for a strictly timed rut is so critical to offspring survival that that timing has become deeply ingrained into the local deer populations genetic code.

Because, in the Southeast, the length of daylight (actually, the length of the nights) only "primes" females for estrus. It is not the only factor influencing estrus timing. It appears that complex hormonal/pheramonal influences can delay estrus timing. Without the presence of specific hormones/pheramones, estrus can be dealyed beyond the time it should normally occur. And the farther south the deer are, the more it can be delayed.

It is surmised that the reason buck age structure plays no role in rut timing in the North is because rut timing there is so critical for offspring survival. In essence, the need for a strictly timed rut is so critical to offspring survival that that timing has become deeply ingrained into the local deer populations genetic code.

...Adult sex ratio: an extremely poor adult sex ratio (few males and many females) will produce a "trickle rut" in that it takes two or three estrus cycles for the few bucks to breed all of the does (although this situation is somewhat rare).