Stoke-by-Nayland peregrine falcons incubating eggs at tower

French said it had been a “huge effort” to monitor the birds’ behaviour, with every switchover between the parents being recorded.

An expert he spoke to had never seen a clutch of eggs not produce at least one chick, French explained.

The Wildlife Trust says that peregrine falcon, external “eggs hatch after approximately 30 days of incubation”.

“The parents are still sitting, they’re still nurturing the eggs, they’re still rotating the eggs, they’re still keeping the eggs warm,” said French.

“If anyone knows whether or not those eggs are fertile, surely it’s the parents.”