Reptile & Amphibian Forums

Here's a good representation of the difference in skull shape and structure between sexes in Varanus boehmei. However this is not a 100% definitive method for determining sex, as I have seen this to not be the case in some of my animals..

The male has the wider, broader head, whereas the female's is narrrower and more tapered.

The other pic is a decent shot I was able to snap of the scalation of the head.

Cheers,

bob
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TheOdatriad

Hi Bob,
I have seen similar head differences between male and female in V. prasinus imports some ~10 years ago. I 'think' I still have the measurements for the male/female I measured then if you're interested?

Cheers, Thanks for sharing,
markb

If you are serious about this, you should compare the female to a male of the same size and same size head, then see if there are any differences. Of course a larger male has a bigger head. But is there actual differences?

I bet there are, but you have not showed them. If you would like an explination, just ask. Thanks FR

Hi Frank.

The two animals whose heads are in that pic, are of equal length believe it or not. Of course, it would be very difficult to compare two animals of totally different sizes, which is why I chose to use the larger of my females to compare to the male. In fact, the female may be an inch or so longer than the male, as her tail tip is slightly missing.

Looking at the pic, you can see that the female's head is much narrower and slender, and not as massive. I can clearly see a noticeable difference between the two, as well as with my other captives(all except those two damn beccari-those do not show any masculine qualities or feminine qualities in their appearance). I said that this can not be a definite way of determining the sex of an individual, as I and many people have found out, is sometimes the case.

While head shape is not always accurate, I would have to say the majority of tree monitors that I have seen and have kept, have noticeable differences in head shape and head size.

What is your take on head shape? As I vaguely remembering you and many others on this forum(back when i was a lurker)responding to people's queries of what the sex of their animals are, going only by photos posted of their heads.. Can this method ever be successful in sex determination, has it ever?? Of course, oviposition is the most accurate way of knowing, but I would guess certain morphological traits can help influence an inference... tailbase is another example I would guess, as in tree monitors, there is a noticeable difference in shape and structure in mature animals.

Other than egg laying, and perhaps certain observed behaviors, what, in your experience, has proven to be successful in determining sex in the monitors that you keep/have kept?

Cheers,

bob
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TheOdatriad

Hi Bob, first I agree the heads can be totally different, but not the way you showed them. There are other widespread(when I say widespread, I mean, covers many species) differences.

From the top, if you use comparable head sizes, the differences can overlap with individuals. That is, some females have broad heads.

Try looking at them from a side view and or better yet, take good side view pics and post them. Then I will show you.

To me, the prasinus group are the visually easist(ok, one of the easist) to sex of all monitors. Cheers FR