Under siege

This was an unusual sight in Gosforth Park Nature Reserve, a siege of herons.  I noticed several herons flying in separately but appearing to land in the same place.  When I got round to the main hide I could see six standing almost in a row on the far bank.  The edges of the lake are nearly all covered in reeds so there isn't usually anywhere for them to stand but the warden has cleared a patch here.  The spacing looks fairly uniform.  I think it must define a heron's personal space.