I have to admit to personally being completely confused by the behaviour on our Loch of the Lowes osprey nest over the last 12 hours. The plot thickens as we still try to confirm the presence in the nest of the first egg of the season, or not!
What we do know for certain is that last night our resident female displayed all the text-book signs of egg laying, going through a range of behaviours you only see in an egg laying bird. Watching this footage on playback today with many different experienced staff and volunteers, everyone agrees that she did in fact appear to have laid at around 10.40pm. She incubated for the rest of the hours of darkness, giving every indication of being comfortably settled on an egg.
We also know that shortly after dawn this morning, she seemed to stop incubating, and lose interest, returning to her outer nest perch, and not paying any attention to an egg at all. This sudden change in behaviour is highly unusual and has us very puzzled indeed.
There are two possible explanations that we can think of for this scenario, both highly unusual:
There is a possibility that our osprey may have laid a ‘phantom egg’, (a bit like a phantom pregnancy in mammals), going through all the behavioural motions as her hormones rage, but not actually producing anything. I have never seen this behaviour in an osprey before, but it is presumably possible- perhaps a fascinating glimpse of new osprey behaviour for us to study.
If in fact our female did indeed lay an egg last night, the other possibility is that she has given up incubating it already as there was a problem with it: perhaps it was not normal, or was damaged in some way early this morning. Her instinctive response would be not to bother continuing to incubate it if it was broken etc and to bury it in the nest.
It is impossible to know which of these two scenarios is more likely unlike more clues emerge- and it is possible we may never know for sure. It is frustrating for all of us that the view into the very deepest part of the egg cup is so difficult even with the HD zooming camera- and that there is moss etc in the way!
So, the mystery deepens, but please be reassured that in all likelihood, whichever scenario has caused this strange change in behaviour, it is likely that our female osprey will go on to lay another egg , or two, successfully yet.