The high tide roost on the river bank opposite Apex Park this morning had quite a few Turnstones but they were massively outnumbered by the Common Redshanks. I guess there were probably 500 or so.  Further downstream the nearly dry pool had approximately two hundred more; until the appearance of a Peregrine, that is. All but 20, and the 2 Spotted Redshanks I had been watching, disappeared in a matter of seconds when the Peregrine made its pass.  Those that remained were huddled together in a tight group.