After sitting on the eggs, with only brief breaks, for quite a while, Emma is now out of the cage and exploring the room. She even came over to me for sunflower seeds, and seemed very hungry. Now she's sitting on the back of a chair preening her feathers all over.

Should I take the eggs out, or wait a day? What hormone control should I start right now? How can I tell if she's thinking about another clutch?

Yes, take them out. She gave up on them. Has 14 hour nights worked? If not, I would try the 24 hour light for 4 days. Let's see if that helps.

Ooops! I spoke too soon. Within an hour she was bak with her eggs and has been sitting on them devotedly ever since. I do wish she would stop. But I guess I just have to be a little more patient.

Whoops. Definitely unexpected.

It's hard to believe how she wants to spend all this time sitting on those eggs. She's usually a very active, inquisitive, destroy everything in sight bird.

I know it's "instinct," but to me hat doesn't really explain anything. How does this "instinct" get imprinted? How do they know they are supposed to sit on that egg when they have never seen another bird do it? How does the cock know he's not supposed to do it?

Sometimes I wish I as young enough to go back to school and become a scientist.

These are "hard wired" and passed down through DNA. The standard pattern goes something like this. The DNA encodes the information needed to create a brain. It is the brain (neuron structure) which is responsible for causing certain types of behavior. DNA is considered the 'code' responsible for creating the 'hardware' of the brain, and that code has in it, the information needed to create the proper neuron structure. So the neuron structure has encoded in it the 'behavior' which therefore doesn't have to be learned.

and how my birds (not very experienced parents) knew that when one newborn chick died, they needed to completely destroy his body to prevent bacteria growth? I never found any remains... I don't even ask anymore.

Its very hard to find the chicks body once its flattened by the parents. The chicks body can be as flat as a dime and the nest box shavings can be mushed with the body. Its a mystery why the chick isn't found. Yes instincts is a really interesting subject.

Thank you, H. Very Interesting explanation. I'm thinking about how complex that neural structure must be. Equivalent to a terabyte, perhaps? That seems like, wow! how can it be that complex. But, then, I think about the eons over which evolution has occurred.

With cockatiels it actually IS the male's job to help sit on the eggs. With most other species the hen sits and the male feeds her.

It's not completely instinctive and there is some learning involved. They learn a lot simply by being taken care of by their parents as babies. Birds that were completely parent raised tend to be better parents (especially the first time) than birds that were removed from the parents at a very early age and handfed.