Fishers?

[Justin Carl]

What are the rostral horns on a Fishers chameleons for?
Directing water into the mouth?
Fighting like the Jackson species?
Show and tell?

 

[Justin Carl]

No answer?

 

[Chris Anderson]

Ornamentation like this has a couple functions. First, it can be used to combat rival males in territory disputes as in three-horned species. Such ornamentation can also evolve as a differentiating feature between sympatric species (species living in the same habitat). Casque size, rostal protuberances and crests are all examples of ornamentation in chameleons which is believed to become increasingly exaggerated to aid in sympatric species differentiation. Basically its driven by sexual selection. If such features overlap in their extent between 2 sympatric species but with one being slightly less and the other being slightly more, in theory, more successful breeding attempts will occur when a female (or male) breeds with an individual exhibiting the feature toward their own species' extreme. Breeding events with an male/female that exhibits the feature in the overlapping zone will only be successful part of the time (the other part of the time, its the wrong species and in theory won't be successful). As a result, the more extreme tends to get propagated and over time, the feature becomes increasingly exaggerated, further differentiating sympatric species.

Chris

 

[Justin Carl]

Awesome!
Thanks for summing that up for me.
So, it dosent have anything to do with directing water into the mouth?
You didnt say anything about that.

 

[Trace]

So, it dosent have anything to do with directing water into the mouth?
You didnt say anything about that.

I've heard that theory to explain the tall shape of the casque in calyptratus but not ever for the fischeri.

Cheers,
t