I haven't written anything for a while due to moving house and generally being very busy. I have been meaning to pen a quick post re the above reptile sexing technique and so here it is. Let me be blunt - I don't think this technique works. Proposed by Danny Brown, as a modification to other candling techniques, the premise runs like this: find a dark room, select a cool yet bright light and shine it through the dorsal base of your reptile's tail. If the tail is not too thick, dark or spineous then it should be possible to discern two red dots in juvenile male animals and a reddish glow. Female juveniles will not have any red dots and instead yield an overall yellow glow.
Sounds great and I tried it myself on two separate species - Varanus.a.acanthurus and N.amyae. I could clearly discern a reddish glow and red balls of tissue on either side of both monitor lizard's tails. Blast - two males! Only when they grew up it became apparent they were in fact 1.1. FAIL.
Above is a pic of what a male should reveal. Both my male and female showed exactly the same aged 12 weeks. And let me be clear - his method says a female would have NO structures in that area. To see the above, according to his method, means you definitely have males.
With the N.amyae I was able to discern two extremely clear red dots on one of the animals and the other had red balls of tissue but higher up. Maybe 2.0 I am thinking and of course the red dots lower down ensured I knew one was definitely male. It perfectly matched the image in D.Brown's book on Australian Geckos. Only when they grew up it became apparent that the one with very clear red dots below the vent was in fact female! FAIL.
The kids and I were thrilled as we huddled together in a darkened room and illuminated our new additions - hopeful that this technique would give us a head start on understanding their gender.
The kids and I were thrilled as we huddled together in a darkened room and illuminated our new additions - hopeful that this technique would give us a head start on understanding their gender.
I tried all kinds of lights and checked my findings multiple times. After discussing the technique with other keepers I am satisfied that it does not work. It is all well and good posting pictures in a book and suggesting: 'I have used the technique on hundreds of animals successfully', but that is hardly scientific. How many of these animals were kept and reared to adulthood - successfully producing offspring and proving their gender without doubt?
I am very surprised that there are not more keepers writing about their experiences with HTI on the web. Well anyway here is mine and safe to say I do not believe this technique is at all accurate as a means of determining reptile gender. People have even started advertising animals on herptile exchange and sale sites like Terraristik.com stating 'sexed using HTI'. I would say there will be a few disgruntled buyers down the line. This is just my opinion based on experience and talking to others - one of whom saw red dots on an entire clutch of yellow ackies (they did not all grow up to be the same gender!).
