Candling involve shining a light through an egg shell to observe the contents of the egg. The process help to reveal the presence of an embryo inside the egg. You can perform this process in a dark room because the darkness will make teh light from the candle more visibly.
During the candling process, look for any indication of life inside the egg, such as veins or movement within the contents of the egg. Robins’ eggs take a while to develop, and during this time, candling can help to follow the development of the embryo inside the egg. When candling an egg at Day 0, you will see a uniform appearance within the egg due to the yolk and an air pocket.
How to Candle and Watch Robin Eggs
On Day 3, you will begin to see veins that emanate from the dark spot in the center of the egg. These appears to be the embryo beginning to develop. If on Day 3 you dont see any veins inside the egg, this means the egg is likely infertile.
Infertile eggs will only display the static yolk inside the shell. Robins uses twigs and mud to construct their nests. They use twigs to create the base of the nest and mud to create a cup to hold their eggs.
They use fine grass to line the nests for a comfortablely sleeping location for the eggs. Understanding how robins construct their nests allow for an understanding of the environment in which the eggs requires to develop and hatch. The embryo inside the egg changes appearance during the incubation period due to the embryo’s growth.
Day 5; blood vessels begin to thicken. Day 7, by this day, the veins begins to take up a large portion of the egg, and you can see movement of the embryo. Day 9, there is an increase in the amount of shadow within the egg.
Day 11, on the eleventh day, the embryo take the appearance of a shadow within the egg that exhibits more significant movement. Day 13. The embryo has grown to the point where the egg appears to be most dark within its shell; the only visible portion of the egg at this stage is the air pocket.
An air pocket is present inside the egg. The air pocket will grow larger over time as the embryo develops. The air pocket will start small, but as the embryo develops, moisture will leave the egg.
If the air pocket is too small, it could mean that the humidity levels within the egg were too high. High humidity levels inhibits the embryo’s development. Therefore, it is important to monitor the air pocket.
The size of the air pocket will show if the humidity within the egg is at an appropriate level. It is important to be able to distinguish between healthy and failed eggs. One indication of a failed egg is the presence of a blood ring inside the egg.
A blood ring indicates that the embryo inside the egg has passed on. If the contents of an egg exhibit murky swirl, this could indicate that the egg is beginning to rot. In this case, you should remove the egg as soon as possible from the nest.
Healthy eggs will continue to darken and show active vein. Failed eggs will exhibit a dead mass inside the egg or a blood ring. To candle an egg, use an LED light to shine through the shell.
LED lights will not emit heat that can harm the embryo inside the egg. Candle the egg for five second at a time, then return it to the nest to keep the embryo from getting too cold. Turn the eggs three times every day to provide even incubation to the embryo.
Even incubation is required for the embryo to grows inside the egg. Many species of birds has different incubation periods. However, the robin take the longest to hatch its eggs.
Sparrows take a shorter time to hatch their eggs than robins. Bluebirds take approximately the same length of time as robins to hatch their eggs but take a little bit longer. Doves take a while to hatch their eggs, but unlike other bird, their eggs are bright white when candled.
Each bird species will have a different incubation period, so it is up to the bird watcher to learn the rhythm of each bird species’ egg development. The final stage of the egg development cycle is when the chick begin to hatch from the egg. By this stage, there will be chirping sound coming from the egg.
The egg will rock from side to side, indicating that the chick is trying to break the eggshell. At the same time, a pip will form inside the eggshell where the chick will break the shell from the inside of the shell, this is known as the internal pip. Then, the chick will begin to create a hole in the outer shell of the egg, which is known as the external pip.
When the chick finally breaks out of the shell, it will dry quick and seek food to begin its life.