Saturday, May 7, 2011

Cockatiel Hens Lay Eggs Even Without Fertilization

I have a friend that said birds do not ever lay eggs unless they have been fertilized by a male. But I told her that birds often lay eggs without a male bird on the premises. She said that was not true. So, I decided to write about how cockatiel hens lay eggs, even without fertilization.
To understand egg laying, we need to understand the hormonal cycle of a cockatiel hen.
There are countless single pet cockatiel hens that begin laying eggs without a nest box or even a suitable mate. A bird that is very bonded to it's owner might consider her human friend as a suitable mate.
Cockatiels are indeterminate layers, meaning they will often continue laying eggs until their clutch is completed. This means that if you remove the hen's eggs right after she has laid them, her hormones tell her to keep laying eggs until she has a clutch underneath her.
The hen will begin to experience a surge in her female hormones based on a number of conditions. These conditions range from abundance of food and water, the availability of a nesting site, the presence of other breeding pairs in the vicinity and a suitable mate (who can be you). Increased daylight, dark corners of the cage, dark corners under the bed or in the room may also begin the hormonal cycle.
It is instinctive behavior for the hen to hold back her droppings for longer periods of time while sitting on her nest. When she gets off of her nest, she will have a larger than normal amount of droppings which are a mixture of feces, urine and urates mixed together. This will give the appearance of diarrhea, but is normal for the hen after she has been holding her droppings in her cloaca while sitting on her nest.
Once the hormones begin their cycle, a number of events will occur. The pelvic floor muscles of the hen starts loosening up to facilitate the passage of an egg. The pelvic bones also become somewhat looser. The pelvic bones of a reproductively active hen can feel a bit farther apart with a little "give" to them. When the hen is not actively cycling, everything tightens up.
During the hormonal cycle of the cockatiel hen, she begins to drink more water because the process of developing an egg requires allot of water that forms the albumen or egg white.
She will then seek for a nesting site which could include a deep food dish or a sleeping hut where she will stay most of the time preparing for the eggs she will lay.
She may become obsessively territorial about her nest. Instead of being her normal friendly self, she might hiss and lash out at anyone that comes close to her nest. This behaviour is caused by your precious friend's hormonal cycle to protect her nest.
Egg laying in cockatiel hens uses a large amount of calcium which is drawn from the bones to help strengthen the egg shell during formation.
To stop this hormonal cycle from occurring, try decreasing the amount of daylight for your friend. Move the bird cage to a different setting, rearrange the toys or add toys to distract your hen. Try some new foods and dietary changes, for this can help her hormonal cycle decrease as well.
A trip to the avian veterinarian is highly recommended to reassure the safety of your beloved cockatiel hen.
But, not every hen that is cycling lays eggs. In some cases the egg yolk is harmlessly reabsorbed prior to ovulation. The yolk can end up loose in the coelom (body cavity). It is called internal laying when the yolk is released into the coelom instead of the oviduct.
Rarely, the yolk is absorbed into the bloodstream which can result in yolk stroke, a dangerous and life threatening situation.
It is very important that you get your hen checked regularly at your local avian specialist. Hormonal treatments can be used to stop the cycling of your precious cockatiel hen.


  1. Would parakeets follow this same cycle? I have 2to budgie females and both are laying eggs. Unfortunately one died from binding.

  2. How do I get a hen off her nest when it is obvious now that the eggs are not going to hatch. (My male bird died recently) :(