Half-sider budgies are the rarest budgie variety all over the world.
Half-sider budgies are not a mutation, but they have a rare condition called tetragametic chimerism that causes the rarest color and type variation in budgies.
Tetragametic chimerism occurs in many living beings, such as butterflies, roses, cats, and humans.



How half-sider budgie occurs?
There is a half-sider budgie due to a known condition called the “tetragametic chimera.” A half-sider budgie occurs when two (or more) fertilized embryos (two zygotes) come together and create a chimeric embryo in the early stages of development, such as between 2 and 64 cells.
Between 2-cell and 64-cell development, the two embryos fuse with their DNA and become like a single embryo. The single budgie embryo continues to grow and become a healthy budgie.
A half-sider budgie is also called a chimeric budgie.

How to produce a half-sider budgie?
A half-sider budgie occurs in particular conditions that randomly happen.
To produce a half-sider budgie, scientists must interfere with embryos during their early stages of development. It is not possible to have a half-sider budgie without a science laboratory.
What is tetragametic chimerism?
Tetragametic chimerism is a rare form of chimerism that is congenital. Plants and wild animals can also have tetragametic chimerism.
Are half-sider budgies bilateral gynandromorph?
Bilateral gynandromorphism means a being has both male and female characteristics with bilateral symmetry.
A half-sider budgie may be a bilateral gynandromorph, asymmetric gynandromorph, or tetragametic chimera.
Half-sider budgie photos & videos
Half-sider budgie photos
![Half-sider budgies [+WITH EXAMPLES]](https://www.petiska.com/wp-content/uploads/2022/04/half-sider-budgies-with-examples-1649774427.jpg)

![Half-sider budgies [+WITH EXAMPLES]](https://www.petiska.com/wp-content/uploads/2022/04/half-sider-budgies-with-examples-1649774748.jpg)
![Half-sider budgies [+WITH EXAMPLES]](https://www.petiska.com/wp-content/uploads/2022/04/half-sider-budgies-with-examples-1649774761.jpg)
![Half-sider budgies [+WITH EXAMPLES]](https://www.petiska.com/wp-content/uploads/2022/04/half-sider-budgies-with-examples-1649774755.jpg)
Half-sider budgie example video 1: A half-sider budgie “TWINZY”
Half-sider budgie example video 2
Is a half-sider but same color budgie possible?
Yes, a half-sider budgie may occur with embryos with the same colors and different DNAs. In this kind of condition, it is hard to understand whether a budgie is a half-sider or not.
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