Given the fact that she laid the 1st egg on March 20th and working out the incubation clock, I make it 4-5 days incubation in March and to date 26 days in April.
This means that hatching of one of the eggs could be a likelihood this weekend, the incubation period is usually 28-33 days so looking at the above we are very close.
I have been watching them as much as possible, admittedly not for long periods on the web cam so it has been hard to confirm whether the full clutch of 4 is still present. Changing position by either bird was only giving glimpses of an egg or 2 and I was constantly missing nest reliefs.
Today however (18th) I finally witnessed an egg relief and confirmed that all 4 were still present and there had been no breakages thankfully.
|April 18th - still 4|
Last Saturday I also watched them from the exterior and witnessed another intruding peregrine, a female again coming in from the north. The Tiercel who was on guard duty promptly intercepted her and gave her a hard time before the incubating Falcon vacated the box and went after the intruder. The Tiercel however gave up on the harassment and promptly flew straight to the box to guard and incubate the eggs. Unlike a recent post (Into April and intruders) where the Tiercel joined the chase and left the eggs totally exposed, this male was a bit more clued up.
The regularity of which I am seeing intruders, not just at one site but many others gives rise to a healthy population as mentioned before in London and the South East but how long will it be before intruders interrupt breeding?
As you may be aware from my London Peregrines website, I do occasionally have some connection with National Grid in relation to pylon breeding peregrines, pylons are an ideal nest site for many pairs and do open up the countryside for breeding peregrines.
Being a Schedule 1 species I can sympathise with NGrid, I would like to place a nest box/Tray or 2 on strategic pylons where pairs are territorial but they have bigger issues due to the fact that they would be liable if someone tried to climb a pylon and was injured trying to get to a box. I found this one quite strange; apparently it is their responsibility to make it unclimable. On top of this, if they needed access on an occupied pylon they would have to apply to DEFRA (everyone’s favourite) to climb said pylon.
However given the regularity of which peregrines are breeding/attempting to breed on pylons across the country and not forgetting pylon breeding Hobbies, I think it is high time they addressed the situation, it will only increase with density.
Peregrines can and will nest on any pylon, I have had a number of discussions with NGrid over this, the fact is that with a stick nest, before they(maintenance) climb the pylon, unless surveyed beforehand they will not know what is incubating in it, Crow or Peregrine or even Hobby.
My argument to them is that by placing a nest box/tray you will contain them to one pylon annually if accepted, which would be very likely for a territorial pair. The theory being that it would not be a lottery every year as to which pylon they would choose, and more importantly since they would know where they are, they would not break any Schedule 1 licensing law unintentionally.
I know that peregrines are pretty resilient birds but a nest box gives them an easier time of it, heavy rain outside but she's bone dry.
Have a look at the photos below, they are of a Saker Falcon in Hungary breeding in a nest box on a pylon, very refreshing to see it, it’s a pity that National Grid cannot find a way to emulate this. The fact of the matter is that many peregrines fail on pylons due to egg rolling or extreme weather/exposure, a specially designed box/tray would alleviate that.
|Pylon nesting ok in Hungary why not England?|