There’s not much to see on the cameras yet, but the hen was away just now (2:20pm) so I checked the nest. All the eggs except one have a small place of broken eggshell. This indicates hatching will occur soon, but a duckling rests for a while after making that first tiny break.
Virtually all of the liquid inside of the egg has been absorbed and is now part of the duckling. An air pocket forms between the egg membrane and the shell even before the eggshell is broken; the shell itself is somewhat permeable to air. A duckling’s first breaths occur when it breaks through the egg membrane and gets to this air pocket. A while after that the duckling slightly breaks the shell and that lets in additional air. Once it’s breathing it can make sounds. You can see the hen react to this sometimes.
I held each of the eggs to my ear and twice I could hear very soft peeping from the duckling and both hear and feel very tiny tap-tap-taps as it pecked at the shell. I tried to record that with my phone so I could put it online for you, but all I can hear in my recording are outdoor noises of songbirds and the breeze – I would need a better microphone to pick it up.
When the duckling is ready to get out of the egg, it starts pecking as it very slowly turns, instinctively using its wings and feet to pivot around inside the egg and eventually – many hours later – the egg is broken all the way around in a ring and falls into two pieces.
You can see the broken shells on several of the eggs, especially the one on the left. The darker egg at the top may be infertile: it shows no signs of hatching yet and is noticeably cooler than the others.
Close-up of the two eggs in the middle, showing some of the work accomplished so far by the ducklings inside.
This photo shows the camera that is bringing you the outdoor pictures. The camera itself is hidden behind black film so the ducks won’t be startled by seeing its “eye” and watching it turn.