dispersal and behavioural changes with time?

We try to make rules about HIM at our peril! Nevertheless, with so many of us making lots of interesting observations, thus accumulating lots of data, there is no harm in trying. Matthew and Ken in particular, have a wealth of experience over many years, and can make an important contribution to this discussion.
Matthew noted in Alice Holt yesterday, that the males were almost entirely chasing around the trees looking for females, with hardly any low level ride skimming flights. We have noted exactly the same change during the last week in UT in several woods: in Bernwood one week ago, I saw only ground skimming flights, whereas yesterday they were only in the trees. In another wood [Finemere] there is a long gravel ride where all the photographers gather to get good shots of grounded specimens. Leading off from this track there is an even longer grassy ride, with no hard core at all.  Two days ago, a member saw six amongst the trees along this grassy ride, and less along the gravel track.  With a highly observant friend , however, I saw none along the grassy track four days ago. So, do the males disperse throughout a wood, after a few days of low level, mineral taking, flights?
Comments please.
I attach  graph showing how the numbers have increased in UT.