Having been to Alberta, Manitoba and Saskatchewan many times, every single guide up there will tell you that the big bucks are killed between 10Am and 2PM there. There reasoning being that in those remote areas, the deer have natural predators (wolves) that hunt at night and have an advantage on them. They bed at night for safety and move around during daylight hours. Since a significant amount of trophy class deer are shot in remote places, or places with low pressure, there is less reason for them to move during the night as opposed to the day.

In the area I am from (NY and CT), I have only seen a handful of quality bucks killed between the hours of 10-2. Most are killed in the last hour of daylight. I would venture and guess that they can move around pretty freely at night where I am from, without any predators, and with the cover of darkness.