Discussion in 'Monitors & Tegus' started by dekor, Nov 2, 2007.
How easy is it to sex a savannah monitor?
It's really, really easy. The one that lays the eggs is the female!
Sexing hatchling, juvie or non-adult monitors is very difficult. Its basically an educated guess. If you've been doing this for a long time and you have a group of small monitors you can *sometimes* guess who's who. This is not scientific at all, its just guessing. Males tend to be more dominant, more aggressive and roam more than females. For example if I have two baby monitors and one is almost always at the highest perch possible and the other spends the majority of the time hiding the hider is possibly a female. Of course, it could also be a timid male.
As they get older it gets a little easier. The larger monitors have pronounced hemipenal bulges at the base of their tails which are fairly easy to spot if you know what you're looking for. Males tend to have larger heads and thicker necks as well. On a male the head kinds blends into the neck, the neck being the same width or nearly the same width as the head. While on a female it tends to taper. Males tend to be larger overall than females and in some species this is really noticeable. As far as the head/neck thing if you have a group of males and females its not that hard to spot. If you have just one it can be trickier, but not impossible. But you will only see this on full grown adults. If they are sub adults you're just guessing.
Then we have the infamous hemipenes. Males will sometimes evert their sex organ. A fully everted male hemipenes "flowers" at the end and its hard to miss. BUT...a partially everted male hemipenes could be confused with the female sex organ which can also be everted. Adult males will sometimes evert their hemipenes and drag it around the cage to scent mark an area. If you notice this behavior you got yourself a boy. If you've had an adult for a number of years and you never see this its most likely a female.
Probably your best bet is the hemipenal bulges. The animal has to be an adult though. Doesnt have to be max size but the younger/smaller it is the more you're just guessing. So if you have a monitor with significant bulges, a large head and a thick neck its most likely a male.
A word on probing. Some people claim they can probe monitors. Monitors are not snakes and this does not work. Its dangerous and not accurate. So if anyone offers to probe your monitor for you grab it and run very fast.
Once again cheers for the advise matey. Personally I believe its a he as where I purchased him from he was the most dominant of the three and the largest (meaning he got to the food before the other two)!
His neck and head are bulky and he just has a sorta manly way to him!
Will keep an eye out for hemipenal bulges.
excellent write-up, varanus99
i would only add:
eversions can be observed easily if the animal defecates in water.
there is a sufficiently broad range of body and head shape variation among savs that, unless one has has plenty of clutchmates for comparison, only hemipenes or eggs are determinant. this is repeating your point, just emphasizing it.
within a year a sav should have matured to the point where a male will make himself unambiguously known.
endoscopy could be performed to try to see ovaries or testes, but there is no genetic test available at this time.
this photo of a male named buzzy was posted recently on another forum:
Hi I was wondering if my female sav will produce eggs on her own without a male aound. Also can I breed her will another monitor say a black throat or a white throat.
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