Having searched a wide area there is still no sight of the missing chick. There are, however, several enclosed courtyards around the cathedral area so she has probably gone to roost overnight. It is now 9.50pm local time and getting dark so I should think she is resting. The male was seen to take off a while ago and has not been seen since - probably just gone to the pub (you know what males are like!!!) Both the RSPCA and the Police are alert for a downed Peregrine so if she is found we will soon know. I should think she will reappear in the morning - more fingers crossed. We will, of course, keep you updated as and when we get more news.
Just to answer some viewers' questions: yes, our remaining chick has been fed by her parents today, so don't worry that she's been abandoned in any way. In recent days the chicks have had very long intervals without feeds. Reports are coming in on Sunday morning that our remaining chick disappeared from the tray around 4.40am local time, and returned some time later.
Update Sunday 9.00am
I have just received a telephone call to say that the 'missing' chick is alive and safely sitting on the dome of the Industrial Museum. All is well.
We'd urge you to read the comments posted by viewers - today they contain more information than our project team can otherwise update you with. Our apologies for any delay in comments being published - all comments currently have to be moderated before being visible - and we've all been a bit busy!