In regard to the response it is true that female gargs absolutely will eat crested and other garg tails ESPECIALLY if a male of either species is present and breeding is a possibility. Unlike cresteds, garg tails grow back and grow back rather quickly. Gargs are a bit chubbier and as a result use up more fatty stores in producing babies. Female gargs when mating with a male will eat the males tail and then a few weeks later when it has grown back will do so again. The point that I am getting at is this act really should not be confused with an act of aggression. It is just all the female knows is she should store up fat for breeding and she is supposed to eat the tail of her mating partner in order to do so.
The garg will treat the cresteds as another garg and not reason that it is a crested and must be treated differently. All that being said, if you have tailess crested geckos nothing that I know about gargs, cresteds, or chahouas would suggest this would be a problem (no multiple males not even a male crested with a male garg or male chahoua).
I'm interested to know how you came to these conclusions? Do you actually own any rhacodactylus or did you read this in a study somewhere?
In my experience gargoyles are cannibalistic and males and females will consume each others tails both during breeding and at random if housed together. In fact I currently have a pair together now that have been together since last fall. My male still has his original tail and my female has regenerated her tail at least 2x due to the male biting it off. Gargoyles are extremely opportunistic and I have had them eat each others tails, frogs, crested geckos (yes, the whole animal), and siblings. I don't believe it has anything to do with the female "knowing she needs to store fat to breed" but more that an opportunity to snatch a meal has presented itself (whether this is a males tail, other females tail, or other animal that will fit in it's mouth doesn't matter). I have successfully kept more docile gargoyles of each sex with adult male chahoua and large adult male cresteds. I did attempt a 6 foot tall 6 foot wide 2 foot deep "New Caledonian" vivarium (similar to your dream project) with a total of 1.5 cresteds, 1.1 chahoua, and 1.2 gargoyles for a duration of 3 years. In that time I only ever had issues with one overly aggressive male crested gecko who simply chased everyone and was replaced with a more docile male and all of the gargoyles. The male gargoyle was found finishing off a green tree frog he'd caught in the tank, one of the females was caught with the stomach of an adult female crested gecko in her mouth (no confusion on tail or species there), and another female was caught persistently chasing and attacking both the other gargoyles and a female crested who frequently visited the lower section of the tank. Due to these issues I determined only the most docile of gargoyles or individuals which were much smaller than their cage mates of any species should even be attempted together. After this realization and change to the inhabitance my multi-species problems went away.
Also, I believe they are quite aware that cresteds and chahouas are in fact NOT the same species. If gargoyles thought other species were also gargoyles they would constantly hybridize. I never saw my gargoyles pursue the opposite sex of any of the other species I kept with them. In my experience rhacodactylus geckos rely heavily on scent, these scents are most likely different depending on species. Granted there are situations where hybridization has occurred in captivity, but there are very few with gargoyles in particular. I believe it has more to do with individuals who are for one reason or another less choosy about their partner and simply pursue any other gecko they can catch to mate with. Also, naturally gargoyles, chahouas, and cresteds typically inhabit different niche areas in the wild. Gargoyles tend to stay lower to the ground and are less arboreal than cresteds and chahouas. Chahouas appear to prefer limbs and travel along branches, and cresteds tend to stay near the ends where there are leaves and branches they can leap to easily.
I have been keeping and breeding rhacs. for 10 years and am no scientist but am extremely observant with the animals I keep. It is also noted in many books regarding rhacodactylus that young gargoyles in particular are cannibalistic and will in fact eat their siblings, not just their tails, and not just adult breeding females.
