Britain is hoping to celebrate the arrival of one or more baby storks.
If the eggs hatch, the arrivals will be the first storks in the UK to breed in the wild since 1416 when a pair nested on top of St Giles Cathedral in Edinburgh.
Portugal is way ahead of Britain on this score.
The nesting birds chose a disused 18th century chimney 35ft above the ground, spurning a structure that had been created for them by the staff at Thrigby Hall Wildlife Gardens near Great Yarmouth in Norfolk.
The four-year-old parents were spotted “copulating furiously” a few days ago and the female is expected to lay her eggs in the next few days.
Storks have bred successfully in zoos in recent times after having their wings pinioned to stop them flying away, but this pair is free to come and go where and when they like.
White storks do not frequent the UK that often with only about 20 spotted each year.
Ken Sims, 72, director of Thrigby Hall Wildlife Gardens, said the birds on his chimney had been bred in captivity in Cumbria and the Cotswolds.
He added: “The building of a nest together is part of their courtship display and an indication that eggs are on their way.”
Once they have built their nest the same pair will often return to it every year to breed. The nest can weigh between 60 and 250kg and have been known to cause chimneys to collapse.
An adult stork has a wingspan of between 155 to 200cm (61 to 79ins).
