Why does the parent move the eggs around?
Periodically rotating and rearranging eggs in a nest ensures equal heating. It also prevents the shell membrane from adhering to the shell, which could interfere with hatching.
More information:
- Egg production
- How an egg hatches
- How Many Eggs Will a Female Lay?
- Why didn’t the eggs hatch?
- Weird eggs (various species)
- Egg sizes (comparison table) for various small cavity nesters
- Nest and Egg Identification (photos and descriptions)
- Supplementing Calcium – Feeding Chicken Eggshells, etc. to Birds
As might be expected of creatures so heavenly in color, the disposition of bluebirds is particularly angelic. Gentleness and amiability are expressed in their soft musical voice. Tru-al-ly, tru-al-ly, they sweetly assert when we can scarcely believe that spring is here; tru-wee, tur-wee they softly call in autumn when they go roaming through the countryside in flocks of azure.
– Neltje Blanchan, Birds Worth Knowing, 1917