Holding our Breath for Hatching
Hot hot hot, is how to best describe our osprey day today at the Loch of the Lowes nest. Our female was so bothered by the flies in the heat today around lunchtime, our Wildlife Interpretation Officer Val saw her snap at and actually catch flies in her beak! On the plus side, there have already been three fish delivered to the nest by the male today, two perch and a pike. Interestingly number three was eaten on the nest by the female- as if she was reluctant to leave the nest- perhaps a good sign?
What is certain is that there has been great deal of egg shuffling and rolling going on , as well as very frequent head titling this evening to listen to the eggs– we know that these behaviours increase markedly towards egg hatching time.
We have had no confirmed sightings of any hole or cracks in eggs yet- we are checking very carefully every time we get a view of the eggs. However, we should remember only about 20-30% of each egg is visible at any one time so it is a matter of luck whether we see the first tiny signs or not.
Q: The main question we have been getting today is about how long an egg can take to hatch?
A: The hatching process starts with “pipping” when the chicks egg tooth breaks the outer shell to create a small air hole in one end. This hole gets a bit larger over a few hours, and the chick then will begin the long process of using its egg tooth to peck a line around the inside of the shell ( around an equatorial line) to crack the eggshell open. This is why hatched eggs invariably have halved along their middle line, and can the whole process can take up to 24hrs (more usually around 6-12hours).
Q: If the first egg doesn’t hatch today will it still hatch?
A: Yes it is still possible.. Osprey incubation varies from 35- 40 days and today is day 37 (the usually average) for this egg, so its not ‘overdue’ yet.
Q: If the first egg doesn’t hatch, will the others also fail?
A: Not necessarily. Some of the eggs may be fertilized and some not, and some may have succumbed to exposure during incubation, whilst others survived.
Q: The female osprey has some different coloured feathers recently- why?
A: The female has been moulting recently, and has started to re-grow some new feathers- these can clearly be seen growing in between the older, paler ones, as new very dark semicircles. These will gradually lengthen and her whole plumage will appear darker.