Candling 33 down to 22

Each day the hen in the west nest continues to battle with other hens forcing their way in to dump eggs. (Here’s more about this “dumping” behavior.) The record highest egg count we’ve ever seen in one nest is 31, but this morning there were 33 eggs in there.

It’s futile: any new eggs will never hatch. Eggs added even a just a day or two after incubation started have little hope of developing in time with the others and these newest ones are a couple of weeks late. Incubation is about half-way done and hatching will occur around May 7th.

Even counting them was difficult two days ago when there were 31 because they were 3 layers deep. So I decided to help: today I removed 11 eggs that have no chance of hatching and there are now 22 remaining.

To determine which eggs to remove I made a “candling” box. Examining eggs with a bright light is called “candling” because in the old days a candle flame was used. Below is a slide show of five pictures. On some screens (a desktop for example) it scrolls sideways and that is not always obvious unless you notice the little arrows at the sides. However if you’ve subscribed and receive blog posts via email then typically the pictures are not in slideshow form and instead are one after the other.

• Picture 1 – shows what duck eggs look like during development when candled.
• Picture 2 – shows the candling box attached to the East nest which is where I tested it since that nest is empty during the day (incubation has not yet started there). There are two holes in the center section: an egg is sitting in one of the holes and you can see the flashlight lamp through the open hole.
• Picture 3 – looks up at the box from underneath. The flashlight is a very bright LED light that has an evenly distributed beam which illuminates both of the holes.
• Picture 4 – This is at the west nest while the hen was away having supper this evening. I hung a dark blanket over the nest box and over me (just like an old-time photographer) and took this picture while under there, checking the eggs. In the center are two eggs that are both lit up in the same way from underneath but the top egg is dark because of the duck embryo inside. The bottom egg is new and has not yet started to develop. It’s very easy to see the difference.
• Picture 5 – Before I put them back, I removed the blanket and took a picture of all of them. On the right are 10 that were undeveloped. On the left and in the center are 23 that had any sign of development that I put back into the nest. (As I put them in I found a cold one in that group and rechecked it. It was very undeveloped too so 22 went back in and 11 were removed.) There is still just one hooded merganser egg: it is on top on the left and it does have a developing embryo inside. Yay! You go little guy!