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Discussion Starter · #1 ·
So I was just wondering how this is possible in the first place. For example, I've seen pictures on the internets of (what supposedly are) leucomelas X tinctorius hybrids. But what I don't understand is how the frogs are attracted to each other in the first place. A tinc call is a low buzz, and a leuc call is a high trill; and from what I understand darts attract mates with their calls. So how does this happen?
 

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In close confinements in captivity reproductive barriers can be broken. For example, it is known that dendrobatids also respond to olfactory cues or even behaviors which could result in the hybrids.

Ed
 

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Captive barriers are for the most part the reason we have hybrid speices, One I have grown to take offense to is the Boleons crosses in the python hobby. A snake that hasnt been bred in captivity here but its being hybridized.

Michael
 

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Discussion Starter · #5 ·
Well I understand that some of the prezygotic barriers to reproduction are gone -- in the case of tincs and leucs, I understand that they occupy slightly different niches (tincs are much more terestrial), and that in captivity they are brought close together and that habitat occupation barrier is gone.

I also get that the mating behavior for these two species are very similar: the male calls to attract the female, the female appears and strokes his back, the male leads her to a egg deposition site, etc..

But the call thing still confuses me. From what I understand calling is a crucial part of frogs attracting a mate, and females preferably chose males with louder calls (calling is supposed to be a very energetically-demanding task, so there is a positive correlation between the loudness of the calls and the individual's fitness). But from what I understand female frogs are only supposed to respond to a certain type of call (differentiating it from all the other frog calls in the forest), and the calls of leucs and tincs just seem too different to me. Although I don't know how similar they sound to the frogs of those species...
 

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As noted above, when kept in close quarters, there is little need for a call.. and other cues such as behavioral can take over, or if the frogs are housed in a group, you can males acting as sneakers in attempting to fertilize eggs or intercept the female. The call isn't all there is to it.. as I noted above dendrobatids are known to have good olfactory senses so close proximity there may even be pheremonal cues (yes they are being discovered in frogs (the first was discovered in Litoria splendens. (sorry not a free pdf but here is the abstract Animal behaviour: Aquatic sex pheromone from a male tree frog : Abstract : Nature))

This is a generalized overview but pheromone producing glands may be wide spread in anurans (not all studied so far have them). http://vri.cz/docs/vetmed/50-9-385.pdf

Ed
 

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Discussion Starter · #7 ·
Ah, muchas gracias señor.

So this is an excerpt from the abstract of the second article:

"The skin glands of anurans secrete various biologically active compounds... The pheromones have an important role in sexual relationships. These chemosignals increase female receptivity and are probably involved in the mate choice. The courtship pheromone signals may be conserved across related species. Chemosignals play an important role in female attraction and/or territorial announcement."

So basically, if you have a viv with tincs and leucs, one of them can just hop in front of the other and (if conditions are right) BOOM! hybrid.
 

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Ah, muchas gracias señor.

So this is an excerpt from the abstract of the second article:

"The skin glands of anurans secrete various biologically active compounds... The pheromones have an important role in sexual relationships. These chemosignals increase female receptivity and are probably involved in the mate choice. The courtship pheromone signals may be conserved across related species. Chemosignals play an important role in female attraction and/or territorial announcement."

So basically, if you have a viv with tincs and leucs, one of them can just hop in front of the other and (if conditions are right) BOOM! hybrid.
Your welcome. It's a complex topic to grasp properly as there are a lot of variables and there are entire books dedicated to it... the use of pheremones is heavy studied in caduates, moderately studied in some caecilians and poorly studied in anurans.

It is possible that if dendrobatids do use pheromones that the scenario you presented could happen... however without going over thier reproductive actions in total, it is possible that there are also behavioral signals that can result.
If you want to see a decent discussion on tinctorius see http://smartech.gatech.edu/bitstream/handle/1853/33895/gaalema_diann_e_201005_phd.pdf?sequence=1

If you can get a copy of this it also may interest you.. I can't remember if it was this survey or another one but I reported that Mantalla aurantiaca when restrained has a distinct peppery odor..

Ed
 

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I always thought they emitted something, whether it was pheromones, some type of sound(wave) etc, because I had a lone male "Uyama" pumilio in a tank for a long time, usually just stayed hidden in a brom and only called during extreme weather, I added a female and they DEFINITELY were out of eyeshot of each other, almost as soon as I put her in and closed the tank he started calling from inside the brom, jumped out and ran around till he found her, then they were off to the races.
 

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Discussion Starter · #12 ·
Hey Ed, the conditioning paper states that the “toe-trembling (twitching or vibrating the toe without moving the leg)” behavior might be used as a visual cue for mating. Do you know of any other papers that talk about the toe-twitch behavior?
 

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Hey Ed, the conditioning paper states that the “toe-trembling (twitching or vibrating the toe without moving the leg)” behavior might be used as a visual cue for mating. Do you know of any other papers that talk about the toe-twitch behavior?
I'd have to dig around but this has to be considered in context with other behaviors. If you are looking at feeding dendrobatids, that toe tapping is not likely to be a visual cue for mating.... one has to look at the behaviors before and after the actions.

Off the top of my head if you can get a copy of Terrarium Animals by E. Zimmerman, TFH Publications there is at least one good description of reproductive behavior (and pattern variations in offspring..).

You may be interested in this paper as well. https://typo3.univie.ac.at/fileadmi...lutionsbiologie/Hödl/sztatecsny_etal_2010.pdf

Ed
 
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