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We were elated to find that 2/7 hatchlings had black heads, though neither parent does! What was odd out of this clutch is the fact that the group is composed of 6 males and 1 female. Any ideas of why such a high percentage of males would occur?
Gen and Tom Anderson
darkmoon reptiles

What temp did you incubate at? I think the lower the higher frequency of females, but I don't have any facts to back this up.

Congrats,

Steven Owens

All our eggs this year were incubated between 78 and 82 degrees. We had too many egg clutches to fit in our small incubator, so quite a few were just set upon a high shelf in their containers. Humidity and temp levels were pretty consistent between the two incubating styles since our reptile room is rather small and the incubator lousy. Sex determination is temperature-dependent in many reptile species. Does anyone have any input about kingsnake eggs?

my understanding is that snakes are NOT temperature linked for sex but rather are gene linked. This sounds like just bad percentages.
J

Most colubrid snakes (Lampropeltines included) have identifiable sex chromosomes. Sex in these snakes is determined through genetic factors in a system like that used in birds (the ZW system). In this system, it's the females that are homozygous (ZW) and the males that are heterozygous (ZZ). This contrasts the system used by placental mammals (XY system) in which the males are heterozygous (XY) and the females are homozygous (XX).

Current research suggests (strongly...) that any offset in the sex ratio of snake eggs incubated at varying temperatures is purely coincidental. It must be remembered that the probability of a trait (color, pattern, sex, whatever)in a clutch of eggs is for each egg individually - each egg has a 50/50 chance of being either sex. Sometimes an entire clutch will hatch the same sex one year, and the following year the same parents could be bred, their eggs incubated exactly the same way, and all of the offspring could be the opposite sex. Very interesting stuff, and there are lots of great papers published on the subject.

-Cole

Those are absolutely gorgeous! I love the little tinge of white on the outside of the banding. As far as temperature, on my alterna that I hatched out this year (Sanderson locale) I just put them in the closet to incubate them and the temperatures were on the cooler side, 76-84 degrees, variable with the room temperatures and I had 5 eggs hatch but hatched out six snakes (twins) and neither parent had a black mask, but half of the babies did. 4 out of six were males. Draw your own conclusions here. I am not real sure if the temperatures make that much difference in sex or not. I am still unable to determine this.

Wayne

Every year I'm high on the female side by about a 70%-30%
ratio. I usually keep the eggs at room temp which is between 75 and 80 degrees. Sound like a temp thing to me.
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Steve W.

Interesting topic.. This year I incubated all of my eggs at 82 degrees.. Just as I have done for many years..

This year one of my females gave me 13 eggs that hatched out 3 males & 10 females.. Last year that same female gave me 13 eggs that hatched with a ratio of 7 males and 6 females??

~ Mike

Well, I did a little research courtesy of google. Sex determination via incubation temperature does not influence a snake's gender, just hatchling viability and body condition. Incubating temperature does influence gender of crocodilians, most turtles, and some lizards. It is the luck of the genetic draw.

Hey, those blackheads look like mine! I got this guy from a breeder in Florida last year. No locality data.

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