|Screengrab of the four eggs which are attracting international attention|
"Female peregrines take two day or more days to form an egg. Since she only laid the second egg mid-morning yesterday (Monday 31st March), she cannot possibly have produced these two new eggs without outside assistance. The only possibility is that both the male and an intruding, mystery third bird have each laid an egg, probably trying to make up time on peregrines elsewhere in the UK which are all well ahead of Derby, with most already sitting on four eggs by now.
"Obviously this is very eggciting news and quite unprecedented - though a similar thing happened once before in Egsville USA. This would be the first occurrence in the UK and in Europe too.
We know that some species of male fish can change sex and lay eggs, so it's not entirely impossible that peregrines could do likewise. And it would also prove that the strange intruding third bird was a female."
The members of the project team are scouring the literature now to try to validate these observations and find other cases.
April 1st 2014
Ps Egged on by the opportunity this provides to further our scientific knowledge, Nick Moyes is abseiling down from the top of the tower now to remove the two extra eggs for analysis - so if you log on and only see two eggs, that will be the reason. There is only one day in the year when such activity is permitted under government lie-cence. And today is the day.