How do birds lay eggs? Most people don’t know it, but all female birds can lay eggs, regardless of whether they have mated with a male.
Think about chickens—they lay all the eggs we buy in supermarkets for us to eat without ever even seeing a rooster. The same is true for a pet bird laying eggs. The difference is that for most parrot species, males and females cannot be distinguished just by looking at them, because parrots do not have external sex organs and males and females only look different in a handful of species.
The Dangers of Egg Binding
When female birds are unable to pass, or lay, an egg that has formed internally, it is known as egg binding. This is a common condition that, if left untreated, can cause infection and death in the bird.
In certain cases, a veterinarian may perform surgery to remove the egg from the bird’s coelom, or abdominal cavity, depending on where it became stuck. When the bird is sedated, this expert will crack the egg and remove it. A licensed avian veterinarian should be consulted if you need help removing a stuck egg.
In order to prevent infection, any shell fragments or residue that may have broken while the egg was still inside the hen must be removed. Additionally, a professional should clean the oviduct, which is the avian equivalent of the fallopian tube.
How Do Birds Lay Eggs?
Female birds ovulate (small swellings that burst) on a regular basis from their ovaries, just like women do. They do this independently of males. Female birds do not menstruate, although ovulation causes women to do so. As an alternative, their ova, also known as ovulated follicles, pass through their bodies and emerge as the well-known hard-shelled eggs.
Although wild female birds ovulate year-round, they typically increase their reproductive activity in response to environmental cues, such as longer days and warmer temperatures in the spring, in order to get ready to lay eggs and raise young. Because they are typically not exposed to these variations in light and temperature, pet birds living in our homes may ovulate and lay eggs year-round.
How Does an Egg Develop?
As embryos, birds have two ovaries. With the exception of certain raptor species and Australia’s brown kiwi, most birds regress their right ovary as they mature, leaving only their left ovary to develop.
The developing follicle on the surface of the ovary ruptures to release the egg, or ovum, which then enters the funnel-shaped end of the oviduct, which resembles a woman’s fallopian tube. This tiny bundle of cells travels down the oviduct with a coating of yolk around it, which, should the egg be fertilized, serves as the “food” source for the growing embryo. After that, the membranes inside the egg, the shell, and another layer of albumen, or “white,” are applied to the ovum inside the yolk.
The hard shell, which is the last to be added while the egg is still in the uterus and right before it exits the bird’s body through the cloaca, contains calcium and other minerals. This common chamber of the cloaca is where the reproductive tract, urogenital (reproductive and urinary) tract, and gastrointestinal tract empty.
Through the vent opening, birds transfer their eggs from inside their cloacas to the exterior of their bodies. This is also the exit point for both urine and stool (the white, solid, chalky part of the urine and the clear liquid urine).
For the egg to properly deflate and not become stuck, its pointed end needs to be facing the vent. In the event that it is not, or if the egg is large, birds may experience difficulties laying, become “egg-bound,” and need veterinary assistance in order to lay the egg.
The majority of parrots require up to two days for the egg to exit the ovary, travel through the oviduct, and exit the vent. Therefore, female parrots can typically lay an egg every other day!
FAQ
Can birds lay eggs without mate?
Why did my bird lay an egg without a male?
Why do birds lay unfertilized eggs?
Can females lay eggs without mating?