Fortunately, Red Grouse shooting is popular enough, and moorland habitat special enough, to get year round attention. Here is a short video I came across that highlights the year round work, the benefits thereof, and some estate shooting of both grouse and pheasant. Oh yeah, there is a little falconry in there too.
A Red Grouse in a North Yorkshire moor.
The closest I've yet to come to grouse shooting, an old grouse butt.