A peregrine intruder caused a flap at Norwich Cathedral, taking over a nest of eggs while the male was gone.

Eastern Daily Press: A young female peregrine, toting an orange colour-ring with the identification letters ‘DP’, lands at Norwich Cathedral. The Hawk and Owl Trust is monitoring the birds.A young female peregrine, toting an orange colour-ring with the identification letters ‘DP’, lands at Norwich Cathedral. The Hawk and Owl Trust is monitoring the birds. (Image: Archant)

The large female trespasser, called DP on her orange tag, is thought to be from London where she was ringed in 2012.

But she returned to Norwich on Saturday, first examining a clutch of four eggs that were incubating and then tapping them with her open beak.

Lin Murray, press officer for the Hawk and Owl Trust who run the Peregrine webcam and the watch point near Norwich Cathedral, said this gave the impression she was toying with the idea of breaking them.

'We will never know for sure what was going through her mind of course but at this time of year, when peregrines who have not found a mate or a nest site still have reproductive hormones coursing through their veins, almost anything could happen,' she explained.

She said the male was much smaller than DP, so would not have stood a chance of winning a fight in the nest box.

'Being smaller and lighter he should be more agile in the air,' she continued. 'So when the intruder eventually left the nest, encouraged to do so by a couple of high speed low passes over her head, the contest became more even.

'The male then hassled, harried and harangued the intruder time and time again in noisy, high speed swoops across the sky above the cathedral.'

While DP was persistent, returning to the nest a further three times in under 15 minutes, she eventually left.

She returned briefly on Tuesday, but the Norwich birds saw her off before she could reach the nesting platform.

The peregrine eggs are now more than a dozen days into their incubation period, which is set to last around 34 days.

With mild weather, and temperatures hitting the mid-teens on several days, the peregrines do not have the added burden of dealing with cold wind or heavy rain.

And Ms Murray said aside from the rogue female DP, it has been a fairly quiet week with the male hunting for food.

She said he would pass it to his partner in a 'spectacular' mid-air manoeuvre, with both birds hollering at each other at the top of their lungs.

The Hawk and Owl Trust watch point, set up on the Cathedral Green, remains open from 10am to 5pm daily until the end of June.

For more visit www.hawkandowl.org