User:Spirit LG/Liolaemus chiliensis

Liolaemus chiliensis (Chilean tree iguana) is a species of lizard in the family Liolaemidae. It is also called the weeping or crying lizard in English. Synonyms for this species include "Liodeira chilensis" and Calotes chiliensis." Less commonly, it is called the Talcahuano Smooth-throated Lizard.

This species is well known for its distress calls, although the sound of these calls does not resemble weeping or crying.

Chiliensis is derived from its country of origin, Chile. It is endemic to central Chile and southwestern Neuquen Province, Argentina. This iguanid lizard is found inhabitting bushes and branches in open forests and ecotonal scrublands or scrub-steppes, chiefly in the Chilean Matorral ecoregion.

Phylogeny
Many previous phylogenetic studies have been incomplete; a more recent biogeographic analysis from 2006 reconstructs the clade that includes this species. Sources differ in whether they refer to Liolaemus chiliensis as a single species or group of species that includes the majority of species in the genus Liolaemus. Some have distinguished multiple species within L. chiliensis due to differences in "snout-vent length, squamation, and dorsal and ventral colors." Much of the debate revolves around the difference between a subspecies and full species. The Liolaemus genus includes over 160 species, and the chiliensis group of species is thought to include almost half the species in genus.

Description


The Chilean tree iguana is relatively large-sized compared to other lizards, reaching 25 cm (9.8 in) in total length. It is an oviparous species. It is carnivorous and feeds mainly on insects and other invertebrates. The maximum body weight is 24.03g. Southern lizards of the weeping lizard tend to be smaller in size. Given their geographic distribution, lizards further south experience climates with lower temperatures.

These dull-colored lizards tend to be green and gray, helping them camouflage against rocks and vegetation. Axilla groin distance is higher in females than in males. Polyploidy results in morphological differences among lizards of different ploidy (i.e. in head shape and various proportions). The mechanisms behind these physical differences are unclear at this time.

Like most reptiles, this species hears with a tympanic membrane. Their otoliths help detection of both acceleration and sound. Their hearing range extends from 500 Hz to 2000 Hz, with a threshold of 40 dB. These lizards excel at recognizing the distress calls of their own species.

Polyploidy
Polyploidy is rare in reptiles, but is significant in this species. The lizard Liolaemus chiliensis has populations with diploid (2n) individuals, triploid (3n) individuals, and diploid-triploid (2n/3n) mosaic lizards. One study found that "33% of females were triploid, 57.1% were mosaics, and 9.5% were diploid" and "86% of L. chiliensis males were mosaics (2n/3n) and 14% were diploids."

Lizards may receive a reduced (n) or unreduced (2n) euploid gamete from their father. In mosaic males, spermatogenesis derives from both diploid and triploid spermatogonia. Although polyploidy can result from interspecific hybridization, Raúl Araya-Donoso, Fernando Torres-Pérez, David Véliz, and Madeleine Lamborot found that a "relationship between hybridization and polyploidy could not be established because triploid and mosaic lizards were hybrids and purebreds."

Behaviour and Ecology
Its diet consists mostly of insects and small invertebrates. Juveniles behave and hunt similarly to adults. These lizards have been observed to display eye-bulging, which is thought to serve a purpose of thermoregulation or even eye-cleaning. This behavior has been observed rarely and only in captivity.

Habitat and Distribution
This species is native to the Neotropics. It is also found in the Chilean Matorral, Patagonian Steppe, and Valdivian Temperate Forests, covering a region spanning Chile and Argentina. A helpful map of its distribution and numerous observations (and their photos) can be found on iNaturalist.

The habitat of this species includes bushes and branches. These lizards bask in bushes that tend to obscure them from possible predators. Predators are also hindered in foraging and hunting. This lizard is adept in running and climbing, and can often be found on branches higher than expected. Their geographical distribution extends from Coquimbo (29°S) to Valdivia (39°S)． It is active throughout the day. Observations tend to be more frequent from September to February, which may be due to its mating season, the warmer weather in these months, or human beings going out more often in warmer weather and consequentially spotting more of these lizards.

Distress Calls
Vocal sound production is rare in lizards outside of Gekkota. The vast majority of non-Gekkota lizards are voiceless. The weeping lizard is the only species in this 'voiceless' genus that vocalized. Weeping lizards are known to produce "distress calls" when stressed, cornered, or threatened, including when seized by humans. Both males and females produces these calls, which are known to sound more like squeaks than hisses or weeping. They include sounds in the ultrasonic range. These distress calls can be heard several meters away from the lizard producing them. These calls increase fear in other lizards. When scared, these lizards become immobile and delay any attempts to escape. The presence of a somewhat consistently high risk of predation reduces the activity of these lizards over long-term observation.

These calls can vary in frequency, linearity, and the presence of harmonics. Compared to females, males tend to emit calls that are louder, more linear, and less complicated. The vocalizations are thought to serve two purposes: 1) they cause antipredatory behavior in conspecific neighbors and 2) possibly deter predators. Complex (nonlinear, erratic) calls have been shown to induce more fear in conspecific lizards than simple calls; the producer of the call may have less control over his or her call if there is a more alarming threat. Distress calls are also more distressing when heard in a familiar environment. Lizards may feel safer in a familiar environment, and therefore more alarmed by surprising causes of distress. On the other hand, the distress calls have been shown to reduce snake predation via a temporary reduction in their exploration, although there is a risk that the vocalization helps a predator narrow down the vocalizer's location. Although seemingly counterintuitive, attracting multiple predators with a vocalization would also serve to be advantageous, because the larger predators would prioritize its safety and the possible conflict with approaching secondary or primary predators in the proximity. When lizards could also detect the chemical scents of other weeping lizards, they mobilized more quickly and more often compared to without the scent. Without the scent, lizards froze to avoid detection; when other lizards were thought to be around, they were quicker to try escaping. Distress calls therefore have been evolutionarily advantageous, increasing the chances of survival both with or without other lizards present.

Lizards from different regions have also shown the ability to distinguish calls from lizards of their own region. Lizards in the northern area tend to react only to distress calls from other northern lizards, whereas southern lizards respond to distress calls from both northern and southern lizards. Given that Southern lizards tend to be smaller in size, their perceived risk of predation may be higher, causing increased sensitivity to distress calls produced by weeping lizards of any region. More research is needed into their means of evasion and escape.

Reproduction
The weeping lizard is oviparous; female lizards lay eggs that hatch outside of her after a period of incubation without her presence. Females prefer to lay their eggs underneath rocks, where the eggs gain a form of protection from predators. Females can lay their eggs as early as October but typically are pregnant in October and lay eggs in November, shortly after the beginning of the warmer season in the Southern hemisphere. Clutches of eggs are usually between 7 and 11 eggs, laid together. The maximum clutch size ever recorded has been 18 eggs. Significant variation in egg clutch size has been documented before. Generally, larger females tend to lay more eggs than smaller females. This trend applies to both mass and volume, since more massive lizards are almost always more voluminous. As a result, previous variation in egg-laying clutch size may actually be a result of unconsidered variation in the sizes of the females who laid the clutches.

Intraspecies Interactions
A study from the Journal of Herpetology suggests that these lizards can detect other members of their species via the presence of lipids in recently deposited feces; however, there is no evidence of further recognition beyond the knowledge that another member of the same species is within the proximity. Both male and females can detect female precloacal secretions of its own species. Once detected, these female secretions prompt movement from both species but higher interest and exploration from males that are possibly seeking a mate. Similarly, females may benefit from releasing these secretions by attracting potential mates.

Interspecies Interactions
This lizard is sometimes preyed upon by the Chilean Green Racer (Philodryas chamissonis). These lizards also undergo parasitism from Spauligodon, a genus of host-specific nematodes.

This species is sometimes kept as a pet by humans, although such a practice violates conservation biology principles, since this species has such a limited range, and is thus vulnerable to habitat disruption and population declines. The species has no history of endangerment or near extinction; today, it is a species of least concern. Their popularity as a pet remains, due to their common presence within this range and their distress calls. These lizards have been photographed being held in human hands near its habitat in natural terrain, suggesting either that a human was able to quickly seize a cautious lizard or that the lizard was curious and calm enough to let itself be held.