Uncle f hit the nail on the head with his comment.
Also someone else put a comment on here sometime back, in that Fallow are possibly the most mismanaged deer out of all the species. Another comment I would pretty much agree with. Many prickets are shot that potentially would make a good buck, but many think a pricket is just that. However a beast with good spikes over 7 or 8 inches long could potentially make a good buck in years to come. But they seem to get shot either way, in most cases to keep numbers down.
Just about where ever Fallow are shot they become nocturnal pretty quickly. They are very good at hiding away on areas where they never get touched, and laying up for the day. This is usually in large groups, even more so in the period between late November and into late February. This adds to the issue of control as its much harder to get a shot, and even if in position its in many cases made harder by the fact that there are no clear shots on an individual animal. In my area we have an abundance of Rhodedendron, which is a nightmare to deal with, the Fallow love it. Plenty of cover, warm, dry and no need to come out until the light fades.
However they can be predictable at times, as they can move from one area to another on a regular basis. This takes time to investigate, and if you do strike on them its only usually possible once or twice. They very soon learn. The way to manage your numbers is to get straight onto them in early November, a soon as the does are in and the rut is over. They tend to be a bit easier to get onto to and in smaller numbers, not the large herds you can get in late winter.