This time of year you will see groups of Roe consisting of all ages. I think with spring just around the corner, and the first flush of new growth particularly browse they are eager to take advantage after the lean months of winter.
Its always suprising how many Roe a small piece of ground will hold, and how little cover they need to survive. I have a modest area in West Sussex, and I have never been there yet and not seen deer. In fact two weeks ago I was on the ground taking a friend out, and we saw 11 Roe on three fields, and took one. From the photo you provided it looks a nice piece, plenty of cover and feed, and the buck in the photo looks to be a good heavy beast.
Let us know how your buck season progresses from April. The rut in West Sussex last year was slightly later than usual, and very short as well.
Cheers.