Only lull I believe in is the common sense lull of the American people...and we my friends are living in it.
It depends on how you define, "lull". In early October, even mature bucks are traveling decent distances to feed in fields during daylight hours. If patterned well, they can easily be killed. As mast falls in and near their bedding areas, they don't have to travel far to feed. Often, they can just stand up and start browsing. Good luck killing that mature buck. He isn't going to hit a field edge until dark-thirty. And, he will likely be within sight of his bed as darkness sets in. As the rut draws closer, scrape activity increases and mature bucks are more likely to move greater distances from their beds, earlier in the evening. In my opinion, your best chance at killing a mature buck is when he is traveling at least some distance from his bed in daylight hours so that you don't have to hunt his bedroom and blow him out. I call it a lull. Because, the chance of killing a target buck is lessened when their pattern changes to a smaller area of movement during legal shooting light. Mature bucks can be killed anytime, but your chances are considerably less during the "lull".
I use to believe the lull was real until I acquired more land to hunt which opened up more stand sites. I do stay out of major funnels and corridors this time of year with the exception being today. There is a major front moving through today dropping the temps all afternoon. This is the only time I gamble but as long as the wind is good I usually have a good sit this time of year.
The lull is real but there is a reason. I see it due to a changing food source and abundance of food. Acorns are dropping and they just don't have to move much to feed. The trick is finding where they are feeding in a vast amount of food. Its like you having all your food in the room next to you or at the store 3 blocks away. The more you must travel the more likely you are to be seen.
If you think of the Lull as less movement during daylight hours, then I would say it exists. If deer transition from fields to mast crop, they are most likely traveling less, therefor less likely to be seen. They still need their essentials, food, water and cover, but their range might shrink drastically during this time. Most likely they would stay that way, but the hormones of the rut switch on and they become more visible again because they are enlarging their range while looking for hot does. I typically hunt edges, so I don't see much activity during this time of year. A couple years ago I hunted some public ground and setup in an oak ridge in a large timber draw. Payed off with a 135" buck on my first sit. I think we need to change our patterns as well if we want to be successful.
I'm a believer in the deer movement changes with the food sources, where i hunt the property went dead cold around the 11th, i had seen deer every sit until then, now i haven't seen one since. The property has no acorns. Where i live are several oaks dropping acorns like pocket change and i see deer a lot!
3 Studies, 3 Strikes for the October Lull https://www.qdma.com/3-studies-3-st...aign=Ntl+Newsletter+10/20/16&utm_medium=email
I saw our #1, a 13 point buck that will push upper 140s to 150, on 10/14 on a windy cold far from perfect night, not in a food plot but moving from bedding to who knows where. That debunked the lull to me.
Do those studies say when the deer were moving? I start getting a lot more buck pictures during what I call the "lull", but 99% of them are in the dark. I think their activity definitely increases, but not when we like.
I don't recall, I just glanced at hem briefly. You can check them out in person at the link I posted I believe. Update** I just looked at them and the third one distinguishes day and night. Also after the first graph it says causes could be going nocturnal. So they aren't really debunking anything except an idea that deer just stop moving at all. To me, a lull means a change in activity that means we as hunters see fewer deer during shooting light. I guess it's highly subjective to one's own ideals.