IncubatedEggsAfter our small coyote duck massacre, I came to realize I have no drakes left. I had winnowed down to two drakes, because too many aggressive breeders are hard on the ladies. Both of them came up missing. I want to always have fertilized eggs so I can breed more ducks from time to time, so a new boy duck is needed. If necessary, I’ll buy one. But for now, I stuck some eggs in the incubator in hopes that I might hatch a male for free. It would be good to increase the flock a little too, I like to keep at least a dozen ducks for laying.

I had one dozen duck eggs in the refrigerator, meant for eating. I pulled them out and warmed them up to room temperature for a day before putting them in the incubator. This practice is dodgy- usually the cold temperatures in the refrigerator will render the eggs unviable. But interestingly, nine of them have started to grow. Today is day seven, and I’ve candled all the eggs to cull any that weren’t fertile or that perished in the first week.

I saved an additional nine eggs laid in the week after the massacre. Laying was down, due to the birds’ stress level. In theory, female ducks who are bred should have about a week’s worth of fertilized eggs in them after a breeding event. In today’s candling, I found that three were not fertile, two had “blood rings,” meaning the embryo had started to grow, but then perished. Four were good.

So, I have thirteen growing eggs in the incubator. I’m groaning over trying to incubate duck eggs in this thing again, because I’ve had very low hatch rates, despite trying all sorts of different things to improve the success. This time, I’m not using the egg turner, as I suspect it puts the big duck eggs too close to the heating elements. That means hand-turning them three times a day. I admit, I’m not perfect at remembering to do this! I’m not putting any extra water source in there for humidity, the hygrometer indicates humidity is at about 65%, just from our normal Northwest air, which is about right, so I’m sticking with that!

When I candle eggs, I sometimes have a hard time knowing for sure what I’m seeing. To candle, I just use a regular “Mag” flashlight, and cup my hand around the top of the light and the bottom of the egg to control the light beam so I can see. I think this works as well as any fancy device might. Sometimes it’s obvious what I’m looking at, but other times the duck egg shells are so thick and full of surface irregularities that the interior is hard to visualize fully.

Here is an egg that is really obviously a good one, you can see the little embryo blob in the middle, and all of the blood vessels radiating out from that. At the top is the air cell, and the bottom you can see bright light shining through the “white” part of the egg interior. The yolk seems to start to change consistency at this stage, the whole side of the egg where the baby is forming will be dark-colored and shadowy, and won’t shift when the egg is turned.


“Blood rings” are standard indicators of embryo death, but I find that sometimes, it can be hard to differentiate them from live embryo growth, which also has a sort of oval ring at the perimeter of the spider-web of vasculature. Books always just show a drawing of what it looks like, which is a poor substitute for seeing the real thing. The big difference is the blood ring is small, and pretty round, with nothing inside the circle; where as live vasculature will spread over much more of the egg; and will always have that little embryo blob in the middle.

Today I saw a really good example of a blood ring (the “X” on the outside of the egg is just a pencil mark for me, to help with turning the eggs):


I cracked it open, and the blood ring shows up well here too. Embryo deaths in the first week can be caused by all sorts of things- rough handling or temperature irregularities in the incubator. Or sometimes, it’s just a bad egg.