> If escapes are put in the  hives before noon, the bees will leave the
supers faster than if     they are put there in the afternoon.

I have found the same here in Australia.  The theory as to why this happens
is that by afternoon, a lot of young bees are moving up in the supers and
these do not seem to be able to find their way out the exits of the clearer
board the same way as older bees  If you look at these the bees remaining, a
lot seem young.

There are two factors that I find that affect the clearing rate of the bees.

Firstly temperature.  If it is hot, then bees do not clear out of the super
as well as if it is cooler.

Secondly space.  If there is not enough room under the clearer board, then
the bees will not go down.

Of course, if there is brood in the super, a lot of the bees will not go
down.

I find that no matter what you do, there is always one hive in the yard that
will not clear out properly.  You can look all you like to try to find our
why but there seems no reason.  Just one of those things.

We use a different type of clearer board exit.  I am getting on of my
friends who has a digital camera to take some photos as I had promised I
would get some for another beekeeper.  Maybe Allen might be interested in
them.

Trevor Weatherhead
AUSTRALIA