This new photo was taken yesterday (11th) by Colin Pass to whom many thanks. Some wing stretch that!!
It may also be the case that one of the more adventurous chicks will climb out of sight onto the higher edges of the platform or up the central black strap giving the apperance that there is only one left. Check carefully for the ends of tails just in view somewhere!
Meanwhile once the weather improves there are likely to be watchers on the ground - at least in the mornings and afternoons and so if one comes down on a road hopefully someone will spot it in time to shepherd it out of danger from traffic.