Candling is a means to check an egg to see if it is fertile, and is also helpful in monitoring the development of the growing embryo.
Candling is simple to do. All that is needed is a small pen light. I added a brass fitting from a hose repair kit to help focus the light. I can also easily view the egg contents. I’ve tried commercially sold candlers and found that this has worked best for candling mousebird eggs. The fittings come in different diameters. I am using the 5/8” diameter. This makes the candler versatile when using a small strong penlight (or LED light) because you can candle from the air cell end or place the egg on the opening of the fitting to view the contents inside the egg. Another plus is the fitting allows enough distance so that the heat from the light will not harm the egg.
Candling is useful for:
Visualization of the air cell, and size.
Fertility status
Detection of a blood ring, which indicates an early death (I’m using a cockatiel egg as an example of this)
Identification of small cracks, which can be sealed with beeswax or Elmers glue.
Movement of the embryo as it develops
Monitoring the blood vessel thickness (integrity)
Problems after the chick has piped. Click on a photo for a larger view
Candling is simple to do. All that is needed is a small pen light. I added a brass fitting from a hose repair kit to help focus the light. I can also easily view the egg contents. I’ve tried commercially sold candlers and found that this has worked best for candling mousebird eggs. The fittings come in different diameters. I am using the 5/8” diameter. This makes the candler versatile when using a small strong penlight (or LED light) because you can candle from the air cell end or place the egg on the opening of the fitting to view the contents inside the egg. Another plus is the fitting allows enough distance so that the heat from the light will not harm the egg.
Candling is useful for:
Visualization of the air cell, and size.
Fertility status
Detection of a blood ring, which indicates an early death (I’m using a cockatiel egg as an example of this)
Identification of small cracks, which can be sealed with beeswax or Elmers glue.
Movement of the embryo as it develops
Monitoring the blood vessel thickness (integrity)
Problems after the chick has piped. Click on a photo for a larger view
Marking Eggs
I have found that the safest marker to use is a Sharpie felt tip marker. It is rated as non-toxic to humans (Look for the AP Seal) http://www.artsafety.org/labels.html
I’ve not had any hatch related problems from using this brand of marker. It has been suggested to use a pencil, but I have found that this can easily crack an egg if too much pressure is applied. I have found that gel type ink pens tend to be absorbed and bleed into the shell. This can be absorbed into the blood vessels that are on the inside membrane surface of the egg, and can be a cause of death to the embryo. The best area to mark an egg is on the wide air cell end. If you are incubating an egg in an incubator many times if manually turning an egg opposing sides of the egg can be marked with a X or O for orientation. If so the safest marker to use is a Sharpie.
I’ve not had any hatch related problems from using this brand of marker. It has been suggested to use a pencil, but I have found that this can easily crack an egg if too much pressure is applied. I have found that gel type ink pens tend to be absorbed and bleed into the shell. This can be absorbed into the blood vessels that are on the inside membrane surface of the egg, and can be a cause of death to the embryo. The best area to mark an egg is on the wide air cell end. If you are incubating an egg in an incubator many times if manually turning an egg opposing sides of the egg can be marked with a X or O for orientation. If so the safest marker to use is a Sharpie.
Some things to look for
Many times before you even candle you can glance at a clutch of eggs and visually see which are fertile, and go by the degree of color to the eggshell how far along they are. If there are eggs close to hatch, and humidity levels have been down, candling will let you know if a problem is in the works. Click on a photo for a larger veiw
Many times before you even candle you can glance at a clutch of eggs and visually see which are fertile, and go by the degree of color to the eggshell how far along they are. If there are eggs close to hatch, and humidity levels have been down, candling will let you know if a problem is in the works. Click on a photo for a larger veiw
When candling the yolk will be centered in the egg, and if fertile the embryo is centered on the yolk with a circle of radiating blood vessels. It is the twisted strands of the chalazae that keep the yolk suspended in the center and allow the yolk to turn when the egg is turned. If manually incubating the egg is rotated side to side. On the nest the parent will shimmy to turn the eggs.
Mousebird eggs are approx the same size as a lovebird egg. The Colius species have plain unmarked eggs, and the Urocolius species have patterned or marked eggs, which consist of speckles and swirls of color. The yolks are a rich orange yellow. Mousebird eggs develop quickly, on an average of 12 days from being laid to hatch. A mousebird hen will lay 1 egg every day. Pip to hatch time is 12-24 hours.
Mousebird eggs are approx the same size as a lovebird egg. The Colius species have plain unmarked eggs, and the Urocolius species have patterned or marked eggs, which consist of speckles and swirls of color. The yolks are a rich orange yellow. Mousebird eggs develop quickly, on an average of 12 days from being laid to hatch. A mousebird hen will lay 1 egg every day. Pip to hatch time is 12-24 hours.
What Does it Mean?
You will hear terms such as DIS, air cells, draw down, and pip and it helps to know what the words mean, and what is going on.
DIS means ‘Dead In Shell’ This term is used when a developing embryo has stopped deveoping and has died in the shell. The most common cause is if the parents got off the eggs too long and they got chilled. If only chilled for a half hour or less, if there was adequate bedding in the nest below the eggs this would retained the body heat. I have found placing a Cobra heat mat on the top of the cage above the nest will generate enough heat to warm the eggs back up. Or if you have an incubator warm and ready place the eggs in it. Allow about an hour to let them warm and then candle them. If the embryo is still alive you will see some movement. If it is an entire clutch of eggs place the egg that appears either infertile or the least developed back in the nest with hopes of the parents go back to the nest to sit. Once the parents are sitting well for an hour or so you can place the other eggs back in the nest. I have found that if the pair have been conditioned to disturbances and the nest being checked they are more reliable tight sitters on the eggs, and will briefly get off the nest but go back once I leave. The most common time for pairs to abandon the nest are at night. During the night they are used to things being quiet and normal, and anything different is pause for them to leave the nest. The most common things are if there is rodent activity in the bird room. Or a lot of loud noises and activity outside. During the day they are more observant and tend to spook if a stranger is present, or a drastic change of color or style in clothing. Prior to breeding season it is best to watch and learn from your mousebirds how they react to changes. There is nothing more heart breaking than losing an entire clutch that was close to hatch. Click on a photo for a larger veiw
You will hear terms such as DIS, air cells, draw down, and pip and it helps to know what the words mean, and what is going on.
DIS means ‘Dead In Shell’ This term is used when a developing embryo has stopped deveoping and has died in the shell. The most common cause is if the parents got off the eggs too long and they got chilled. If only chilled for a half hour or less, if there was adequate bedding in the nest below the eggs this would retained the body heat. I have found placing a Cobra heat mat on the top of the cage above the nest will generate enough heat to warm the eggs back up. Or if you have an incubator warm and ready place the eggs in it. Allow about an hour to let them warm and then candle them. If the embryo is still alive you will see some movement. If it is an entire clutch of eggs place the egg that appears either infertile or the least developed back in the nest with hopes of the parents go back to the nest to sit. Once the parents are sitting well for an hour or so you can place the other eggs back in the nest. I have found that if the pair have been conditioned to disturbances and the nest being checked they are more reliable tight sitters on the eggs, and will briefly get off the nest but go back once I leave. The most common time for pairs to abandon the nest are at night. During the night they are used to things being quiet and normal, and anything different is pause for them to leave the nest. The most common things are if there is rodent activity in the bird room. Or a lot of loud noises and activity outside. During the day they are more observant and tend to spook if a stranger is present, or a drastic change of color or style in clothing. Prior to breeding season it is best to watch and learn from your mousebirds how they react to changes. There is nothing more heart breaking than losing an entire clutch that was close to hatch. Click on a photo for a larger veiw
Air Cell
The air cell is the best means to monitor how an egg is doing in various stages of development. The inside of the egg has 2 membranes, the inner membrane which encases the growing embryo and contents, and the outer membrane that is adhered to the inside of the shell. When an egg is layed it is the body temperature of the hen. As soon as it is expelled from the body it meets with cool air., which cause the shell to cool, and the inner membrane near the round portion to contract, which forms a small air pocket. I have learned to get familiar with the size of the air cell of an egg that is a day old. As the chick develops the air cell will stay the same size. It is when the chick is approx a day or 2 from hatching that the air cell size and shape will change. This is a visual guide to if the egg is going to hatch normally or if there is a problem.
Some problems that can affect the air cell are humidity. If there is too much humidity the air cell will decrease in size, because of fluid retention in the egg which causes swelling of the chick and it can smother the chick if it has already turned and ready to do an internal pip.
If the air cell increases in size the last few days (up to 1/3 the inside of the egg) of incubation this is an indicator that the humidity levels were low and the interior of the egg is dehydrating which can cause the membrane to stick to the chick and prevent it from hatching successfully.
If the air cell shows that it is lower on one side this is a good sign that the chick has turned and is facing the air cell, which will create, what is called draw down. As the chick pierces the inner membrane at the edge of the air cell the membrane will form tightly over the body. At the lowest point will be what is called the internal pip.
External pip is when the chick cracks through the shell using the egg tooth at the tip of the bill. Once the external pip is make the chick is able to vocalize and it can be from 12-24 hours until it hatches. right after the first external pip it will have to draw the blood supply from the veins into the body and then the yolk.
Trapped in Shell is when the humidity is low and the membrane adheres to the upper body of the chick. When this happens the chick is unable to rotate around the circumference of the egg to cut the shell and hatch out. The chick will be very vocal and if the external pip mark has been in the same place for 12 hours, there is a good chance the chick may need assistance in getting out of the egg.
Click on a photo for a larger veiw
The air cell is the best means to monitor how an egg is doing in various stages of development. The inside of the egg has 2 membranes, the inner membrane which encases the growing embryo and contents, and the outer membrane that is adhered to the inside of the shell. When an egg is layed it is the body temperature of the hen. As soon as it is expelled from the body it meets with cool air., which cause the shell to cool, and the inner membrane near the round portion to contract, which forms a small air pocket. I have learned to get familiar with the size of the air cell of an egg that is a day old. As the chick develops the air cell will stay the same size. It is when the chick is approx a day or 2 from hatching that the air cell size and shape will change. This is a visual guide to if the egg is going to hatch normally or if there is a problem.
Some problems that can affect the air cell are humidity. If there is too much humidity the air cell will decrease in size, because of fluid retention in the egg which causes swelling of the chick and it can smother the chick if it has already turned and ready to do an internal pip.
If the air cell increases in size the last few days (up to 1/3 the inside of the egg) of incubation this is an indicator that the humidity levels were low and the interior of the egg is dehydrating which can cause the membrane to stick to the chick and prevent it from hatching successfully.
If the air cell shows that it is lower on one side this is a good sign that the chick has turned and is facing the air cell, which will create, what is called draw down. As the chick pierces the inner membrane at the edge of the air cell the membrane will form tightly over the body. At the lowest point will be what is called the internal pip.
External pip is when the chick cracks through the shell using the egg tooth at the tip of the bill. Once the external pip is make the chick is able to vocalize and it can be from 12-24 hours until it hatches. right after the first external pip it will have to draw the blood supply from the veins into the body and then the yolk.
Trapped in Shell is when the humidity is low and the membrane adheres to the upper body of the chick. When this happens the chick is unable to rotate around the circumference of the egg to cut the shell and hatch out. The chick will be very vocal and if the external pip mark has been in the same place for 12 hours, there is a good chance the chick may need assistance in getting out of the egg.
Click on a photo for a larger veiw
COMING SOON I am still adding to this page...
How to Help Assist a Hatch
Egg Developement this will photos of candled eggs from day 1 to hatch
Egg Developement this will photos of candled eggs from day 1 to hatch
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