In my reading and studying, I remember or at least I think I did. Something that said the female will determine the sex of the chicks. I might be confused in all of this, but is that because of the X and Y in regards to the two X's of the cock. Or does outside factors mitigate it, such as an imbalance of male and female budgies. At the time of Hedwig laying her eggs, there was 8 cocks and 7 hens.

Save me writing it out:

 

Avian sex determination (Ellegren 2001) -- The molecular determinants behind sexual development in birds remain a mystery. The process is known to be different from that in mammals, with no homolog to the gene that confers maleness in mammals found in birds. The failure to identify such a gene in birds is probably a reflection of the fact that, despite the occurrence of two sexes being nearly universal throughout the animal kingdom, the genes involved seem virtually unrelated among metazoan phyla. These differences raise obstacles for comparative or candidate gene approaches in studies of sexual development.

In birds, females are the heterogametic sex, with one copy each of the Z and W sex chromosomes. Males are homogametic (ZZ). However, it is not clear whether it is the presence of the female-specific W chromosome that triggers female development, or the dose of Z chromosome that confers maleness. An intriguing additional possibility is that both Z and W matter! In marsupials, for example, Y acts as a dominant testis determining chromosome, while the X chromosome determines the choice between pouch and scrotum. Maybe a system where the two sex chromosomes mediate different aspects of sex differentiation is also used in birds.

 

Source: Avian Reproduction

 

Additional curious info from same website:

 

Female birds can bias the sex of their chicks.-- Whether a bird is more likely to lay a male or female egg depends on which sex will have the greatest chance of doing well. Rutstein et al. (2004) adjusted the food intake of female Zebra Finches [see photo of female (left) and male (right) Zebra Finches below right] & found that well-fed females were more likely to produce daughters, while less well nourished birds were more likely to have sons. This is exactly as predicted by the fact that female offspring need to be better nourished than males if they are to survive and grow well.

The authors noted that: “In most animals sex ratio is close to 50:50 and extremely resistant to change. In mammals, including humans, the sex of the baby is determined by whether the sex chromosome in the sperm is male or female. But in birds, it is the female’s egg rather than the male’s sperm that determines what sex the chick will be. Thus the female has the potential to determine the sex of her young by whether she ovulates male or female eggs. In some way, female Zebra Finches seem to be able to exert control over whether to produce a male or female egg depending on which of the two is most likely to be successful. Our research tells us that they do it, and we understand why. The big question is: how do they do it?”

In many animals, females need to be well-nourished and in good condition if they are to breed, as eggs are costly to produce. Bigger eggs tend to lead to bigger young that are more likely to survive. Such ‘sex ratio adjustment’ is well documented in certain insects, such as bees and wasps, but is less well understood in birds and mammals.

Birds are an excellent model to use in the study of sex ratio adjustment because, using molecular techniques, scientists can establish the sex of each egg soon after laying. Further, all the resources given to the developing embryo are present in the egg at laying. Thus the size and the content of the egg are measures of the amount of resources that the female has allocated to that egg, which affects its subsequent survival chances.

The authors explained: “We manipulated the diet quality of Zebra Finches to look at the effects of body condition on female investment. We found that females were able to exert a strong degree of control over the production of male and female eggs. When females were fed on a low quality diet, they laid eggs that were considerably lighter than those laid when they were fed on a high quality diet, and they also laid far more male eggs on a low quality diet. This is the converse situation to that described 30 years ago for mammals, but it makes sense for Zebra Finches. Previous research has shown that under poor nutritional conditions, female Zebra Finches grow more slowly and survive less well compared to males. Therefore, females are producing more of the sex with the highest survival chances under those conditions.”

Thanks Dean for that information. I appreciate it :nest:

Source: Avian Reproduction

 

Additional curious info from same website:

 

Our research tells us that they do it, and we understand why. The big question is: how do they do it?" ...

 

 

... Previous research has shown that under poor nutritional conditions, female Zebra Finches grow more slowly and survive less well compared to males. Therefore, females are producing more of the sex with the highest survival chances under those conditions."

 

 

I think it's absolutely amazing that this is possible! :emoticon112:

Reminds me of how Kaz said she got a whole buncha female chicks last season. I on the other hand had mostly males. Hmmm... Room for dietary improvements perhaps?

 

Care to share your feed regime secrets Kaz?

I am wondering if the youngest isn't female, I pick it up to hold and all it does it bite me rofl. We are hoping it's female, we plan on keeping the youngest regardless of sex. Come to think of it, they all bite me,lol.

I have started giving my hens hulled oats, and I think that has helped. The toher hens are still laying, but one pair has hatched 6 chicks and got 4 females, one cock and one undetermined.

WHEN THEIR IS A DROUGHT MORE FEMALES ARE HATCHED THAN IN WETTER WEATHER woops sorry caps

its known fact that more heat the more hens

WHEN THEIR IS A DROUGHT MORE FEMALES ARE HATCHED THAN IN WETTER WEATHER woops sorry caps

its known fact that more heat the more hens

 

I dunno about that GB. Last summer I bred 40 odd males and 6 odd females. I wanted it the other way around

 

This winters breeding (as bad as its been for live hatches) has gotten me 3 hens and one cock so far...

Someone once told me and said on this forum that poorer feed means more hens.

My reply was I was getting nothing but hens in nests and my birds eat better than we do !!! FACT

 

 

we had better add some of this stuff into the OLD WIVES TALES category

Edited September 6, 201014 yr by KAZ

lol, what's everyones opinion on the whistler brand of budgerigar food. There is a special going on at the shops. I normally buy trill.

I find all commercial (Trill, Whistler etc.) for breeding birds to be c***.

One of the top breeders here was only talking to an interested person (wanting to breed budgies) about how it is bad for the birds that are breeding.

Birds need proper seed with high enough protein and food that is good for them. For two birds to breed and have healthy chicks, the birds must be healthy themselves and be apple to supply protein, fiber and calcium to their chicks.

 

This is a personal opinion, also based on a reliable breeder.