TWO unexpected guests have taken up residence at York Minster.

The peregrine falcons have been nesting on the Gothic cathedral during recent months and bird watchers believe they may now be about to extend their flock.

The protected peregrines, known as the duck hawk in North America, have been seen mating and nest scraping – behaviour which experts suggest means they are about to lay eggs.

Mark Thomas, senior investigations officer at the RSPB, said: “While peregrines don’t physically build a nest, they do construct a scrape – a shallow depression deep enough to stop eggs rolling away.

“They normally choose raised locations, for example cliff edges, but tall buildings are increasingly being used, so York Minster will seem like a perfect home to them.

“Their breeding season is in late March or April, and this, along with the behaviour observed over recent weeks, suggests the female is about to lay eggs.

“In the British Isles peregrines do not migrate and the majority stay within 100km of their birthplace, so any offspring may well stay within the Yorkshire area.”

The birds are renowned for their speed and can reach up to 180km an hour when catching prey.

The female peregrine can normally lay three to four eggs but both birds share the incubation, which normally is expected to take about 29 to 32 days an egg.

Rebecca Thompson, superintendent of works at York Minster, said: “We’re excited the peregrines have chosen this iconic building to nest and look forward to following their story. We’re taking advice from experts to ensure we protect the birds from any disturbance as we continue our ongoing restoration and conservation work on the building’s 800-year-old fabric, and hope to have news of new arrivals soon.”