Memorial Day Ducklings
Incubation has started in the East nest. Yesterday one of the ducks that has been visiting the nest box every morning stayed all day and now she’s there overnight too. The other sure sign that incubation has started is that she has surrounded herself with a thick blanket of down. So new ducklings should arrive in 30 days plus or minus a few. If it turns out to be exactly 30, that will be on Monday May 27th.
The East nest a couple of days ago.
Usually the male wood ducks show little interest in the nest box interior, but this one peeked in to see how his mate was doing.
East nest opinions
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!
East 10
At least two ducks continue to visit the east nest box every morning and there were 10 eggs in there this morning. One of the hens is quiet and the other one (“Chirpy”) clucks continually – it’s a very noticeable difference. I think they’re both laying eggs. I’ve posted videos recently (Apr 4 and Apr 18) of an incubating hen vigorously defending her nest from an intruder but sometimes two will share a nest peacefully. These two were together for about 20 minutes before one of them left. No drama, just sitting together.
Incubation here will begin in a week or so but has not started yet. We know that because the nest box is empty except for an hour or so in the morning and occasionally for a little while in the afternoon. Until the eggs are kept continually warm they are dormant and do not begin to develop. This is why they hatch within hours of each other even though some were laid a couple of weeks before the others.
31!
There are now 31 eggs in the west nest box. 23 are visible in this picture but there are 9 more underneath. It’s likely that even more will be added since more than one duck barges in each morning and often leaves another egg after putting up with a lot of neck biting and shaking and squawks from the resident hen. The all-time record in our nest boxes is 31 eggs (25 of them hatched) so that record will be broken. The eggs are a couple of layers deep and that makes the incubating hen’s job more difficult.
Ducks are visiting the east nest too, but there are still only 3 eggs in there.