Reptile & Amphibian Forums

I would just like to know the male/female ratio's you got this year. I know once added up it will most likely come out close to 50/50, but I want to see real #'s and not just guess.

Thanks

Follow this link to the Ralph Davis Reptiles birthing record page. You can go through each year and get tons of data. Then plot the distribution of gender ratios and see if it is the normal bell curve with the expected peak around 50/50 or some other distribution, which averages 50/50. If it isn’t the bell curve it might give some insight into an unexpected way that the female produces her egg cells (the female’s genetic contribution determines the gender of the offspring).
RDR Birthing Record

Learn something new, I didn't realize that with balls the female decides the sex of the offspring. How exactly does that work?
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Nita Hamilton
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Ball Pythons

If I remember right the snake (and I think bird too) gender chromosomes are labeled z and w. The females are wz and the males are zz. So it comes down to each egg being a girl if mom gave her a w or being a boy of mom gave him a z. It's pretty much the opposite of people where the males have the unmatched gender chromosomes (xy) and the male determines the gender of the offspring by either contributing a y to his sons (to make xy) or an x to his daughters (to make xx).

Randy - is there any information to suggest that a female may throw a higher percentage of females to males consistantly or is it continually random based on clutch?
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Tosha

"One of these days i am going to wake up..look around...and realize my place looks more like "Ace Venturas"s than my own." Coldthumb

7.33.0 Ball Python (Harry and Fluffy and gang)
1.0.0 Angolan Python (Skywalker)
0.0.1 Green Tree Python
0.2.0 Feline (Pippen and Pandora)
0.0.1 Dessert Tortoise (Pope John Paul "JP"
2.2.1 Fish (1,2,3,4)
0.0.2 frogs rescued from pool skimmer
0.0.1 lizard rescued from vicious feline

People like to gripe or brag on getting lopsided clutches depending on what they where hoping for. It could just be reporting bias (you aren't going to hear about or remember all the near 50/50 clutches).

The graph of all the clutch ratios from a big program like RDR would be a good way to look for unexpected tendencies. I think several years ago I went through the clutches he had posted at that time and confirmed the 50/50 average but I can't remember if I went as far as to confirm the expected normal distribution. If there was a tendency for clutches to cluster around gender imbalance rather than around 50/50 you could then start the harder task of finding females that have a long track record to look for a tendency in individual females to one extreme or the other. The problem is we haven't been breeding all that many females all that long.