The birds have each been fitted with two rings that will help conservationists monitor peregrine populations.
The trust said young peregrines could be difficult to sex and that DNA records allowed them to build a clearer picture of the birds’ breeding success, movements, survival and family connections over time.
During the ringing process, they were able to see the weight of each chick with the male weighing 665g (1lb 7oz) and the two females weighing more than 800g (1lb 12oz) each.
Thompson said: “We are really lucky. Where they are on the west tower you can see them gliding, swooping and hunting.
“It’s fascinating to watch and they are quite vocal as well, peregrines – even if you haven’t bothered to look up, it’s such a distinct sound.
“It attracts lots of people to come and have a look and set their cameras up to try and capture the peregrines.”