As many of you are aware Norwich Cathedral has of late had a regular intruding bird, the intruder ‘DP’ is showing up with some regularity and has even got to the nest site.
From past posts you will know that I was present at the ringing of this female on May 25th 2012, even then she was simply enormous and bigger than the other female. I know there is always going to be size difference between siblings making a difference in size but even so the size between the 4 was very apparent.
The brood consisted of 2 Tiercels and 2 Falcons, all fledged successfully but one was lost rather early on, a male unfortunately.
|DP on right, as you can see quite big then.. Photo courtesy of John Black|
From earlier posts it is always good to hear of ringed birds and sightings but rather mischievously she has made a bit of a nuisance of herself to the Cathedral pair. What she is doing is an everyday occurrence, intruding peregrines go with the territory, and it comes from having a better population than years gone by. Visiting the nest site is normal and healthy, getting to the nest tray is a little unusual but I dare say it has happened before on other sites but this time was recorded by CCTV.
I have no doubt that she would not have got to it if the resident Falcon was present, as it was the incubating Tiercel did very well to stay as long as he did.
He was obviously intimidated by her but that is part of the conditioning of every Tiercel, Falcons are always dominant, even intruding ones. In open sky he could have been more aggressive but without the support of his mate all he can do was probably dive her.
Since then, video and photos were very kindly forwarded by the Hawk and Owl Trust, BBC Norfolk have picked the story up and are calling her a ‘ rogue ‘ Peregrine and an egg breaker, I take it that this is the BBC dramatising the event, a bit extreme.
|Tiercel holding his ground|
|Inspecting the eggs|
|Just about to leave|
In any event she would be more likely to brood them rather than break them I would have thought, although there would be no bond to the eggs.
|BBC Norfolk article|
If she continues to cause mischief there is a possible case for a takeover, hopefully not during incubation, the chick stage or fledging, that would not be good for obvious reasons.
Her natal site is urban so I expect that she will be more attracted to Cities – Towns and large buildings/structure, this is one of the reasons that I expect she is in Norwich, additionally the presence of the resident pair.
If she stays in Norwich one possibility that could alleviate the situation, is to give her a nest box or tray to herself, she comes from one. Not sure how many tall buildings/structures there are in Norwich and if any are sufficiently of a height/compatible and suitable for nesting but ideally that may help. Additionally it would have to be at a far enough distance away, territories in London were once a 2-3 mile radius between pairs, on one site now it is about ½ a mile, both Tiercels regularly clash.
If she stays she must be roosting somewhere on a favoured building, the BTO survey may well turn her up.
Of course she could just be passing through looking for a Tiercel on territory; the above is just a possibility if she continues to stay.
Whatever happens, I hope there is no takeover although it is just part of the natural process in peregrines, hopefully she can find a territory of her own, there’s certainly enough Tiercels out there for her.
Below is a link to the video, as you can see she is pretty careful around the eggs, also she is constantly looking up, no doubt expecting attack from the returning Falcon.