How To Tell If Cockatiel Eggs Are Fertile

How To Tell If Cockatiel Eggs Are Fertile

Cockatiels, known for their ability to breed year-round under suitable temperatures and housing conditions, can lay eggs even without a mate. If you have a pair of cockatiels and notice eggs, you may be curious to know how to tell if cockatiel eggs are fertile. However, if you want to confirm if an egg is fertile, several methods are available.

To determine if a cockatiel egg is fertile, check for two eyes and yolk on the shell. After the egg is laid, promptly remove the shell within a minute. Within this timeframe, the presence of eyes and a yolk will indicate fertility. Additionally, you can easily discern the fertility of a cockatiel egg by examining its color and shape.

Fertile cockatiel eggs undergo a noticeable transformation within a few days of incubation. They become a vibrant, consistent white color.

On the other hand, eggs that appear dull or gray, or retain a pinkish or beige hue are non-viable and considered dead.

How To Check If Cockatiel Eggs Are Fertile

Cockatiel eggs are ideal for incubation, but it’s important to confirm their fertility before placing them in an incubator. Here is how to do that and how to tell if cockatiel eggs are fertile:

Candling the eggs

Candling the eggs

Throughout the incubation period, a fertile egg undergoes various stages of development. To assess the fertility of eggs in a new clutch of chicks, you can employ a straightforward method called “egg candling.”

Egg candling involves the use of a light source, like a candler, to examine the interior of an egg and identify the presence of a growing embryo.

However, it’s important to note that you cannot candle a freshly laid cockatiel egg. You must wait at least seven days after the egg has been laid before attempting to candle it. This waiting period allows the female cockatiel to finish laying all the eggs in the clutch and begin incubating them.

Once you have visually observed the female cockatiel sitting on the eggs, indicating she has started incubation, you can initiate the countdown of seven days. After this waiting period, you can proceed with egg candling to determine the fertility of the eggs.

Here is how to candle the egg to check if it is fertile:

  • Hold the egg against a bright light source, such as a candler, at an angular distance of 5–6cm away. If you are considering getting a candler, check out this one on AmazonOpens in a new tab..
  • A fertile egg exhibits clear indications of development, including the presence of intricate blood vessel networks, an opaque embryo shape at the larger end of the egg, and even movement inside.
  • Conversely, a fertile egg with halted embryonic development will display a blood ring or blood streaks visible within the egg. As the embryo becomes non-viable, the blood vessels that previously sustained it retract away.
  • An infertile egg or a yolk will appear transparent without any presence of blood streaks, rings, or visible vessels.

Floating test

Floating eggs often indicate infertility because the internal volume of the egg is insufficient for it to sink. Therefore, it’s important to wait until the cockatiel’s eggs are a few days old and all potential embryos have developed before handling them.

Moving the eggs too frequently can hinder development if done too early or harm the developing chick if done too late.

To perform the test, prepare a bowl of warm water and gently place the eggs in it, being cautious due to their fragility.

For a potentially fertile bird egg, it’s important to use warm water.

Observe whether the eggs float or sink. A heavier and denser egg will sink to the bottom when placed in water, while an infertile egg will float.

If the eggs are determined to be fertile, dry them with a towel and place them back in the incubator.

Inspect the status of an egg

Determining the fertility of an egg is simple. Instead of cracking it open, look for a light-colored area called a blastodisc. This small spot indicates the presence of a blastoderm, which develops into a chick.

Monitoring live eggs is usually unnecessary unless you plan to hatch them. Check the eggs immediately after laying and transfer them to a hatchery promptly if you aim to hatch chicks.

To identify fertile eggs, look for a distinct, solid, and opaque white circle or bullseye called the blastoderm, surrounded by a lighter, transparent outer layer.

Infertile eggs have irregularly shaped, faint white blastodiscs.

Remember, all eggs contain a blastodisc, or white spot, regardless of fertility.

Behavior changes in parents

Observing the behavior of the parent cockatiels can provide valuable insights into the fertility of the eggs. Here are some signs to look out for:

  • Increased nesting behavior: If the female cockatiel spends significant time inside the nest box, it is an encouraging sign that the eggs are fertile.
  • Protective behavior: The male cockatiel may become more protective and territorial around the nest, indicating the presence of fertile eggs.
  • Regular incubation: Both parents take turns incubating the eggs. If they follow a consistent schedule, it suggests that the eggs are viable.

Keep a close eye on the behavior of the parent cockatiels and document any notable changes. These observations can help you determine the fertility of the eggs.

Separate female from male cockatiels

By mating females with males of another species, it is possible to create an egg with genetic material from both genders. An unfertilized or female-only-produced egg is known as a blastodisc.

Blastodiscs have distinct bands resulting from the combination of chromosomes.

When an egg is fertilized or contains genetic material from both males and females, it transforms into a blastoderm.

A blastoderm is an early stage of embryonic development that arises from the collaboration of male and female genetics occurring after the blastodisc stage.

The formation of blastoderms depends on the successful interbreeding of two species and can occur in eggs with either solely female genetic material or a combination of both genders.

Observing eggs for 14–21 days

Observing eggs for 14-21 days

Bird eggs, regardless of the species, have varying incubation periods before hatching. If an egg surpasses this time without any signs of development, it is likely infertile.

However, it’s important to note that this method is not suitable for checking hen eggs.

Eggs left in an incubator for 21 days or kept at room temperature for 7 to 10 days may become spoiled.

Now, let’s explore how to determine if a cockatiel egg is fertile or infertile with a few simple indicators.

The easiest method is to examine the egg’s air cell.

If the air cell appears large and around, the egg is unlikely to be fertile. Conversely, a small and pointed air cell suggests fertility.

As the chick prepares to hatch, the air sac within the egg becomes tilted, indicating its turning motion and readiness to break through the shell.

Another approach involves placing a few drops of hydrogen peroxide on the egg. If the hydrogen peroxide bubbles up, it is likely a sign of fertility. If no bubbling occurs, the egg is probably infertile.

See Also: Can Cockatiel Eggs Hatch Without A Male?Opens in a new tab.


There are various reasons why individuals may seek to determine the fertility of cockatiel eggs. Some may want to check if their pet cockatiel is pregnant, while others may desire to personally hatch a cockatiel egg.

One reliable method used by breeders involves a straightforward test. By cracking open the eggshell and examining the contents, you can assess its fertility. If the interior appears dense and uncomplicated, it is likely infertile.

However, if the content appears soft and contains numerous air bubbles, there is a higher chance of it being a viable, fertile egg.

Cockatiel Enthusiast

My name is Bojan. I have been around Cockatiels for the past 7 years. I love writing about Cockatiels and helping people understand how these beautiful birds live, what they like, and how to provide them the best possible care.

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