Barely two weeks old, the peregrine chicks at Norwich Cathedral are all still healthy and accounted for after a team climbing the spire uncovered an infection in the male.
Each year the Hawk and Owl Trust choose an opportune moment when it will cause the least distress to attach rings to the legs of the newborns.
The unique identity rings help birdwatchers across the country identify the birds and track their movements.
And this year was the first time they have taken DNA samples from the birds, in a bid to learn more about the genetics of the various sub species of peregrine.
'We don't want to stress the peregrines out too much, and this year's group seemed so confident we felt it would be the perfect time to take some DNA, particularly because the parents are so used to us now,' said Claire Halls, a rehabilitator for the Raptor Trust.
'The DNA samples can prove for a fact what gender they are - something we couldn't do definitively before with chicks, and would help us match them up if anything happens to their parents.'
Ringing the three females went without incident, until the team realised the male chick seemed underweight. Investigations revealed a case of sour crop - an infection in the chick's mouth, and Wood Farm Vets in Wymondham were contacted. 'We found there was some food stuck in its throat so it had difficulty swallowing, wasn't eating and was losing energy,' said Martin Lippiatt, of the Hawk and Owl Trust.
'Because the infection was causing him harm, he could have been dead within the week if we hadn't seen it today.'
Abiding by the strict non-intervention policy, the vet only acted because a human presence had already been introduced. 'Healthy chicks can be ringed and put up with that additional stress,' added Ms Halls. 'Because one wasn't 100pc healthy we had to negate that stress.
'All we wanted was to get him back on an even playing field. He is not out of danger yet, but it is looking positive. If we hadn't caught it now but hadn't introduced that additional stress he might have had a 50/50 chance.
'Now that is more like 60/40 in his favour.'
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