Anolis proboscis

One of the most notable features of the species is its proboscis - a pliable, blunt appendage extending beyond the snout approximately 85% of the head length.[4] Although the exact purpose of the appendage is unknown, male to male combat can be ruled out due to its highly flexible nature. Beyond sexual selection, the proboscis may help males appear larger, which could lend a significant advantage in male to male interactions, despite not acting as an actual weapon.[6] Finally, because of its sexually dimorphic nature, the proboscis' use in thermoregulation or as a lure for hunting prey can also be ruled out.[6] Because the dewlap of A. proboscis is comparatively underdeveloped compared to other Anole species - it is far smaller and less colorful - the appendage could compensate and act as an ornament, as it is prominently displayed during mating rituals.[7] Likely, it serves as an intraspecific communication signal, and could also play a role in territorial displays as a way for males to assert dominance over each other or in mate choice.[6][4]

In order to attract a mate both males and females display their dewlaps, employing variations of extension lengths. Males have been seen with their dewlaps extended and their proboscis drooped downward while courting.[4] Males are able to slowly change the stiffness and direction of their horns when courting. Other courting behaviors that have been observed include swinging of the head from side to side, known as "proboscis flourishing," and up and down when approaching a female all while the dewlap is displayed, either half or fully extended.[7] Courtship is deemed successful if and when the females runs past the male and continues in the opposite direction which leads to the second stage of mating called chasing. The female may perform a push-up with her forelimbs along with a head-bob and extension of her dewlap in response to the male's courting.[7]

Chasing progresses when the female prompts the male to follow by running past him in the opposite direction. It involves the male following the female in quick short sprints one to three steps long while frequently bobbing their heads in the same pattern as seen in courtship. Chasing ends with the female arching her neck, or when the male begins to climb on her tail with his forelimbs.[7] If the male cannot successfully follow the female, no mating occurs.[7] Similar behavior has been observed in A. carolinensis, suggesting that is a challenge issued by the female as test for the male before mating can begin.[7]

Next, the stimulation stage begins when the male catches the female and the female arches her neck in response, signifying readiness for copulation. The male must mount the female and find a good position to copulate in. As the male does this, he is constantly rubbing her nape with the tip of his snout in order to stimulate the female and to elevate the female's rostral appendage.[7] Males have also been observed biting the female on the nape, which then stopped after copulation.[7]

The copulation stage begins after the male and female have found an appropriate position together. Once this happens the male inserts one of his hemipenes into her cloaca.[7] There is no specific time length for copulation but mating ends when the male and female have separated. There are a variety of displays by the male that may occur after copulation, including head bobbing, extension of the dewlap, which the female may or may not respond to.[7]

Anolis Proboscis reproduces oviparously. In captivity, females lay a single egg, which is incubated for roughly 165 days (5.5 months).[5] Interestingly, males are born with a proboscis already formed, which lengthens as they develop.[14]

Male agonistic behaviors can occur when two males attempt to court the same female. Non-violent agonistic behaviors from males include attempts to display at each other, chase the other male away, open their mouths to display teeth, arch their neck, raise their backs and probosces, and keep their heads down.[7] They may also bring their rostral appendages against each other's faces, touching the opposing male with the tip or their snout, or perform slow tail undulations.[7] Further, the males have been observed performing a movement resembling a push-up, whereby he moves his body forward with his head and tail down, and then back, raising his head and tail in the process. During this display, the male's dewlaps will be extended, the tail curled up, and the proboscis straight.[14] These behaviors are intended to scare away the other males, potentially by making the male appear larger. They have also been recorded turning sideways and straightening out their body, extending their tongues, perhaps to accentuate their body length.[6] Violent agonistic behaviors can include biting and pushing of other males.[7] Agonistic behaviors can last as long as it takes for the other male to stop attempting courtship. Unlike many other reptile species with prominent proboscises, A. proboscis does not use the appendage as a weapon, and may even attempt to protect it when fighting.[14] During violent male-male interactions, the proboscis remains lifted, and some specimens bear scars, suggesting the appendage can be injured.[14] In general, the species appears to be less aggressive than other kinds of anoles, which falls in line with the behavior of other twig ecomorphs.[14] Unlike species like A. marcanoi or A. carolinensis, there are far fewer attempts at biting or "jaw locking" during male-male conflict.[14]