Anolis evermanni

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Anolis evermanni
Anolis evermanni.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Suborder: Iguania
Family: Dactyloidae
Genus: Anolis
Species:
A. evermanni
Binomial name
Anolis evermanni
Stejneger, 1904

Anolis evermanni, also known commonly as the emerald anole, Evermann's anole, and the small green anole, is a species of lizard included within the family Dactyloidae. [2] [3] A. evermanni is native to Puerto Rico, where it is mainly found in wet forests. A. evermanni is a medium-sized lizard and bright emerald-green in color. [2] [3] A. evermanni is studied for its behavior as well as the evolution of the family Dactyloidae. The group of lizards which are member species of the family Dactyloidae are known as anoles. [4] [5] Anoles are found throughout the Americas and are related to iguanas. [6]

Contents

Description

A. evermanni is medium-sized and a bright emerald-green color, but can also progress to a dark brown color when aroused. Males are typically larger than females with males having a snout-to-vent length of 7 cm (2.75 in) and females having a snout-to-vent length of 4.5 cm (1.75 in). They have a flattened body and head, slightly compressed tail, pointy snout, short legs, and large toe-pads. Males and females both have a yellow dewlap, a flap of skin hanging below the neck. Male dewlaps are generally larger than female dewlaps. [2] [3]

Anolis evermanni on a beach Anolis evermanni on a beach.jpg
Anolis evermanni on a beach
Anolis evermanni with extended dewlap Anolis evermanni dewlap.jpg
Anolis evermanni with extended dewlap
Brown Anolis evermanni BrownAnolisEvermanni.jpg
Brown Anolis evermanni

Distribution and habitat

A. evermanni is native to and found in Puerto Rico. Specifically, it can be found in wet forests including the El Yunque rainforest, the Luquillo mountains and forest, and the Cordillera Central mountain range. [2] [3]

In these areas, A. evermanni is typically found around trees, on rocks, or bamboo groves. It mainly use the upper portions of trees, 2 m (6.6 ft) above the ground, as perching sites and to search for food. Its short legs and large toe-pads allow it to move more easily in the upper portions of trees, particularly on small branches. [2] [3] [4]

Conservation

The International Union for Conservation of Nature lists A. evermanni as a least-concern species as the species remains common in Puerto Rico, and its habitat has no widespread threats. Current threats include residential and commercial development as A. evermanni is not found in deforested areas. Additionally, climate change is a threat to forest habitats in which A. evermanni is found. [1]

No species-specific conservation efforts are taking place for A. evermanni. However, it is most often found in protected areas which conserve its natural habitats. [1]

History and taxonomy

A. evermanni is a species of lizard named after Dr. Barton Warren Evermann, an American ichthyologist. [3]

A. evermanni is in the anole genus Anolis, which includes over 400 species of lizards native to the Americas. Anoles typically share similar sizes and shapes but differ in the habitats they occupy. This is an example of adaptive radiation as lizards on different islands adapt to different habitats. The genus Anolis is part of the larger family Dactyloidae of anoles. This is an example of convergent evolution where lizards on different islands with similar habitats may evolve to share similar morphologies. [6]

Within the genus Anolis, A. evermanni is classified in the trunk-crown ecomorph, generally living in the upper trunks and canopies of trees. Other trunk-crown anoles include A. allisoni , A. coelestinus , and A. grahami . [6]

A. carolinensis is another related lizard species which is also able to change colors between shades of green and brown. [6]

Genome

From 65 to 125 million years ago, anoles experienced radiation into the different species found today. Anoles vary greatly in their karyotypes with A. evermanni having a diploid number of 26 chromosomes while other anoles having a diploid number as large as 44. They also vary in their sex chromosomes with some species having simple XX/XY sex chromosomes and others having many sex chromosomes. [5]

Diet

Similar to other trunk-crown Anolis ecomorphs, A. evermanni eats small insects. A. evermanni has also been found to eat the nectar of Mecranium latifolium flowers in Puerto Rican forests. This is a recent finding, but other anoles have also been found to lick nectar from flowers. Some anoles may be pollinators of certain flowers. When foraging, similar to other anoles, A. evermanni is typically a sit-and-wait forager, meaning it has long periods of inactivity followed by short bursts of activity to capture prey. [6] [7] [8]

Reproduction and life cycle

Reproduction

A. evermanni females display seasonal changes in egg production. From April to September, most A. evermanni individuals are reproductive, and many females have two oviducal eggs. Almost no reproduction occurs between November and January. [9] Like other anoles, A. evermanni females lay eggs and hide them. [10]

Behavior

A. evermanni, in addition to other anoles, has been studied for its behavioral interactions and evolution. [4] [5]

Territoriality

A. evermanni is a territorial species, with both males and females using displays of their dewlaps, tails, and tongues to defend their territory from other lizards. When these displays fail, A. evermanni may also fight over territory. [2]

Anolis gundlachi, a competitor of Anolis evermanni Anolis gundlachi facing camera.jpg
Anolis gundlachi, a competitor of Anolis evermanni

Competition with Anolis gundlachi

A. evermanni has been found to interact with other lizard species including A. gundlachi. Both lizard species are native to Puerto Rico and they are of similar sizes. However, they are ecologically different as A. gundlachi typically occupies the lower portions of trees while A. evermanni occupies upper tree areas. Regardless, competition between the two lizard species still exists. In a study on the interactions between the two species, when A. gundlachi is removed from an environment, the number of A. evermanni was found to increase over time. This may be due to interspecific competition between the two lizard species. The two lizard species share similar prey of insects and have been found to contest territory. Similar to behavioral displays between A. evermanni lizards, with two different species, the lizards also use push-ups, their dewlaps and tongues to compete for territory and prey. In this case, A. gundlachi has been found to win encounters over A. evermanni counterparts. Intraguild predation is also possible among these lizards with male A. gundlachi adults potentially eating A. evermanni juveniles. Without the competition with A. gundlachi, A. evermanni was able to occupy areas, mainly lower tree trunks, that were previously defended by A. gundlachi. [4]

Other possible hypotheses regarding the ecological differences between A. evermanni and A. gundlachi include having common predators and parasites. But in this case, as the two lizard species are in close distance to each other, it is unlikely that these factors have a significant role. [4]

Biting

A. evermanni, as well as other anoles, bite other animals and humans. However, most anole bites are harmless and only done as a protective measure when provoked. [11]

Coloration and behavior

A. evermanni is typically bright emerald-green which does not blend in well with tree trunks but may blend well with other vegetation. However, when aroused, A. evermanni will turn a dark brown color which may camouflage it with tree trunks. [12]

Problem solving

A. evermanni has been studied to test its behavioral flexibility. Lizards are believed to have limited cognitive abilities. However, in a study with A. evermanni, the lizard was found to adjust its behavior in order to receive a reward. In this case, lizards learned to remove a disc in order to obtain food. This study demonstrated adaptation capabilities within A. evermanni. [13]

However, whether this behavior can accurately assess behavioral flexibility has been disputed. Other researchers contend that A. evermanni has demonstrated learning abilities but not necessarily a flexible learning ability. [14]

Enemies

Predators

Predators of A. evermanni include terrestrial predators like snakes. A. evermanni may also perceive humans as predators, and other animals like birds may be predators as well. As it is typically found on or near trees, when approached by a terrestrial predator, A. evermanni exhibits escape behavior by climbing around or up a tree. This behavior varies depending on the perch height of the A. evermanni individual. If a lizard is lower in a tree, the lizard exhibits escape behavior more quickly when approached by a predator than if the lizard were higher in the tree. At perch heights less than or exactly 2.0 m (6.6 ft), A. evermanni individuals exhibit escape behavior, but at perch heights above 2.0 m, no escape behavior is exhibited. [12]

Physiology

Locomotion

A. evermanni locomotion depends on location, showcasing different movement on boulders and trees. A. evermanni exhibits jumping and walking behavior at similar levels on boulders and trees. However, running behavior is increased 238% on trees. Overall locomotion for A. evermanni is 46% higher on trees. Its short legs and large toe-pads aid locomotion on trees. Another possible explanation for increased running and movement on trees is that tree trunks provide a continuous area for A. evermanni to move on. Additionally, A. evermanni is heliophilic and may move toward areas with sunlight including the forest canopy and gaps in the canopy where sunlight can reach. [8]

Interactions with humans

A. evermanni is often found on coffee plantations in Puerto Rico, especially in areas nearby forests. A. evermanni is being affected by human activity and forest conversion in its natural habitats as it does not continue to live in deforested areas. A. evermanni has not been found to have other significant interactions with humans and is not involved with major human uses or trade. [1]

Related Research Articles

<span class="mw-page-title-main">Dactyloidae</span> Family of reptiles

Dactyloidae are a family of lizards commonly known as anoles and native to warmer parts of the Americas, ranging from southeastern United States to Paraguay. Instead of treating it as a family, some authorities prefer to treat it as a subfamily, Dactyloinae, of the family Iguanidae. In the past they were included in the family Polychrotidae together with Polychrus, but the latter genus is not closely related to the true anoles.

<i>Anolis</i> Genus of lizards

Anolis is a genus of anoles, iguanian lizards in the family Dactyloidae, native to the Americas. With more than 425 species, it represents the world's most species-rich amniote tetrapod genus, although many of these have been proposed to be moved to other genera, in which case only about 45 Anolis species remain. Previously, it was classified under the family Polychrotidae that contained all the anoles, as well as Polychrus, but recent studies place it in the Dactyloidae.

<i>Anolis carolinensis</i> Species of reptile

Anolis carolinensis or green anole is a tree-dwelling species of anole lizard native to the southeastern United States and introduced to islands in the Pacific and Caribbean. A small to medium-sized lizard, the green anole is a trunk-crown ecomorph and can change its color to several shades from brown to green.

<span class="mw-page-title-main">Brown anole</span> Species of lizard

The brown anole, also known commonly as the Cuban brown anole, or De la Sagra's anole, is a species of lizard in the family Dactyloidae. The species is native to Cuba and the Bahamas. It has been widely introduced elsewhere, via the importation and exportation of plants where the anole would lay eggs in the soil of the pots, and is now found in Florida and other regions of the United States including southern Georgia, Texas, Louisiana, Tennessee, Mississippi, Alabama, Hawaii, and Southern California. It has also been introduced to other Caribbean islands, Mexico, and Taiwan.

<i>Anolis roosevelti</i> Rare or extinct species of reptile

Anolis roosevelti, also known commonly as the Virgin Islands giant anole, Roosevelt's giant anole or the Culebra giant anole, is an extremely rare or possibly extinct species of lizard of the genus Anolis in the family Dactyloidae. The species is native to the Virgin Islands and Vieques.

<span class="mw-page-title-main">Knight anole</span> Species of lizard

The knight anole is the largest species of anole in the Dactyloidae family. Other common names include Cuban knight anole or Cuban giant anole, highlighting its native country, but it has also been introduced to Florida. In its native Cuba, this large anole is called chupacocote.

<i>Anolis pulchellus</i> Species of reptile

Anolis pulchellus, the Puerto Rican anole, Puerto Rican bush anole, snake anole, or sharp-mouthed lizard, is a small species of anole lizard in the family Dactyloidae. The species is among the most common lizards in Puerto Rico, and also native to Vieques, Culebra, and the Virgin Islands.

<span class="mw-page-title-main">Blue anole</span> Species of lizard

The blue anole is a species of lizard in the family Dactyloidae. A. gorgonae falls into the genus Dactyloa, which are all highly arboreal, but differ in size, coloration, and perch preferences. The blue anole specifically occupies higher perches. It is a small species which is "near threatened" and found only on the island of Gorgona, in the Colombian Pacific.

<i>Anolis cristatellus</i> Species of reptile

Anolis cristatellus is a small species of anole, belonging to the Dactyloidae family of reptiles. The species is native to Puerto Rico and the U.S. and British Virgin Islands, with introduced populations in locations around the Caribbean. The males of A. cristatellus are easily recognizable by the fin running down the top of the tail, which is known as a "caudal crest". The females also have this crest, but it is smaller than that of the males. The species is often quite common in many areas on Puerto Rico, where it can be seen during the day passing the time on the lower parts of tree trunks, or on fences and the walls of buildings in urban areas, sometimes venturing down onto the ground in order to lay eggs, have a snack, or do other cursorial activities. Like many anoles, this species displays the characteristic behaviour of doing push-ups as well as inflating a pizza-like flap of coloured skin on its throat, known as a dewlap, in order to show others how dominant it is, and thus attract mates or intimidate rivals.

<i>Anolis allisoni</i> Species of reptile

Anolis allisoni, also known commonly as Allison's anole or Cuban blue anole is a species of lizard in the family Dactyloidae. The species is endemic to Cuba, the Bay Islands and Cayos Cochinos off the mainland of Honduras, and Half Moon Caye off the mainland of Belize. There is also a single doubtful record from Cozumel, Mexico. Recently, the species has been documented in southern Florida. This diurnal species is commonly seen on palm trunks, and it feeds on invertebrates. It is among the relatively few anole species in which females may lay their eggs together, forming a communal nest.

<i>Anolis occultus</i> Species of reptile

The Puerto Rican twig anole or dwarf anole is a species of small, arboreal anole endemic to Puerto Rico and primarily inhabiting the Cordillera Central from the Sierra de Cayey range in the Southeast to the central-western ranges of Maricao. A mostly grey to olive-brown bodied lizard, A. occultus is the smallest of the Puerto Rican anoles with a snout to vent length of 34–42 mm. In comparison to other twig anoles, A. occultus is extremely cryptic through its unique sleeping behaviors and mottled pattern. Sleeping behavior including site selection minimizes the probability of predator encounter along with A. occultus' extensive list of antipredator behaviors.

<i>Anolis grahami</i> Species of lizard

Anolis grahami, commonly known as the Jamaican turquoise anole and Graham's anole, is a species of lizard in the family Dactyloidae. The species is native to the island of Jamaica, and has also been introduced to the territory of Bermuda. It is one of many different species of anole lizards found in Jamaica. There are two recognized subspecies.

<i>Anolis cuvieri</i> Species of reptile

Anolis cuvieri is a species of lizard in the family Dactyloidae. The species is endemic to Puerto Rico, and is common in the Toro Negro State Forest.

<i>Anolis</i> ecomorphs Grouping of species of lizard

The ecomorph concept is a term first coined by Ernest Edward Williams in 1972 which he defined as a “species with the same structural habitat/niche, similar in morphology and behavior, but not necessarily close phyletically.” Williams first applied this definition to the Greater Antillean anoles upon observing their evolutionary radiation, although it has since been used widely elsewhere.

<i>Anolis proboscis</i> Species of lizard

Anolis proboscis, commonly known as the horned anole, Ecuadorian horned anole or Pinocchio lizard, is a small anole lizard in the family Dactyloidae. A single male specimen was discovered in 1953 in Ecuador and formally described by Peters and Orces in 1956, but the species then went unreported until its rediscovery in 2004. Its currently known habitat is a small stretch of vegetation along an Ecuadorian highway. It has been classified as Endangered by the IUCN due to its restricted distribution and ongoing habitat loss.

<i>Anolis stratulus</i> Species of reptile

Anolis stratulus is a moderately-sized species of anole found in Puerto Rico, the United States Virgin Islands and the British Virgin Islands. It is a gray-colored lizard spotted with brown markings. It is arboreal, usually found positioned on tree bark on branches in the canopies of forest trees, where in some areas of Puerto Rico it can be incredibly abundant, with tens of thousands of the lizards being present per hectare.

<i>Anolis lineatus</i> Species of lizard

Anolis lineatus, the Curaçao striped anole or striped anole, is a species of lizard in the family Dactyloidae. It is native to Curaçao and Aruba of the Netherlands Antilles, but has also been introduced to Klein Curaçao. It is generally common, and is particularly common in densely vegetated gardens in the capital Willemstad. It is found in dry tropical shrubland at all elevations in its range, but is uncommon in habitats without larger trees. It can often be seen on rocks, the walls of buildings or tree trunks; at various heights but often relatively close to the ground. It is a member of the A. chrysolepis species group.

<i>Anolis aquaticus</i> Species of reptile

Anolis aquaticus, commonly known as the water anole, is a semi-aquatic species of anole, a lizard in the family Dactyloidae, native to southwestern Costa Rica and far southwestern Panama. The species demonstrates adaptations that allows it to spend periods of time underwater up to approximately a quarter of an hour, forming an air bubble which clings to its head and serves to recycle the animal's air supply while it spends time beneath the surface. Although highly unusual, similar adaptions and behavior are found in other species of semi-aquatic anoles.

<i>Anolis auratus</i> Species of lizard

Anolis auratus, the grass anole, is a species of lizard in the family Dactyloidae. The species is found in Costa Rica, Panama, Venezuela, Colombia, French Guiana, Guyana, and Brazil.

<i>Anolis gundlachi</i> Species of lizard

Anolis gundlachi, also commonly known as the yellow-chinned anole, Gundlach's anole, and the yellow-beard anole, is an oviparous, sexually dimorphic species of lizard in the family Dactyloidae. The species is endemic to Puerto Rico and lives in mountainous forests at high elevations. The diet of A. gundlachi consists mostly of insects. This species is also known for signaling other lizards through a modulated head bob display, with varying bobbing amplitudes and patterns based on an individual's distance from other lizards.

References

  1. 1 2 3 4 Mahler DL, Rodriguez C (2020). "Anolis evermanni ". The IUCN Red List of Threatened Species 2020: e.T74995322A75171581. https://www.iucnredlist.org/species/74995322/75171581. Downloaded on 29 March 2021.
  2. 1 2 3 4 5 6 "Emerald Anole". United States Department of Agriculture Forest Service. Retrieved 7 October 2021.
  3. 1 2 3 4 5 6 Uetz, Peter; Hallermann, Jakob. "Anolis evermanni STEJNEGER, 1904". The Reptile Database. Retrieved 7 October 2021.
  4. 1 2 3 4 5 Leal, Manuel; Rodriguez-Robles, Javier; Losos, Jonathan (1998). "An experimental study of interspecific interactions between two Puerto Rican Anolis lizards" (PDF). Oecologia. 117 (1–2): 273–278. Bibcode:1998Oecol.117..273L. doi:10.1007/s004420050658. PMID   28308498. S2CID   6208194 . Retrieved 7 October 2021.
  5. 1 2 3 Giovannotti, M (22 March 2016). "New insights into sex chromosome evolution in anole lizards (Reptilia, Dactyloidae)" (PDF). Chromosoma. 126 (2): 245–260. doi:10.1007/s00412-016-0585-6. PMID   27001473. S2CID   23204455 . Retrieved 7 October 2021.
  6. 1 2 3 4 5 Uetz, P.; Hallermann, J. (2018). "Dactyloidae". The Reptile Database . Retrieved 7 October 2021.
  7. Colón Archilla, Alfredo (Sep 2010). "Nectarivory in Puerto Rican Emerald Anoles (Anolis evermanni)" (PDF). IRCF Reptiles & Amphibians. 17 (3): 145. Retrieved 7 October 2021.
  8. 1 2 Losos, Jonathan (1990). "Concordant evolution of locomotor behavior, display rate and morphology in Anolis lizards" (PDF). Animal Behaviour. 39 (5): 879–890. doi:10.1016/S0003-3472(05)80952-2. S2CID   53167129 . Retrieved 7 October 2021.
  9. Gorman, George C.; Licht, Paul (March 1974). "Seasonality in Ovarian Cycles among Tropical Anolis Lizards". Ecology. 55 (2): 360–369. Bibcode:1974Ecol...55..360G. doi:10.2307/1935223. JSTOR   1935223 . Retrieved 7 October 2021.
  10. "Family Dactyloidae: Anoles". KingSnake. Retrieved 7 October 2021.
  11. Revell, Liam (18 June 2012). "Field Work in Puerto Rico and a First Lizard Bite". Anole Annals. Retrieved 7 October 2021.
  12. 1 2 Cooper, W.E. (24 March 2006). "Risk factors affecting escape behaviour by Puerto Rican Anolis lizards". Canadian Journal of Zoology. 84 (4): 495–504. doi:10.1139/z06-018 . Retrieved 7 October 2021.
  13. Powell, Brian; Leal, Manuel (13 July 2011). "Behavioural flexibility and problem-solving in a tropical lizard". Biology Letters. 8 (1): 28–30. doi:10.1098/rsbl.2011.0480. PMC   3259950 . PMID   21752816.
  14. Vasconcelos, Marco; Monteiro, Tiago; Kacelnik, Alex (7 December 2011). "On the flexibility of lizards' cognition: a comment on Leal & Powell (2011)". Biology Letters. 8 (1): 42–43. doi:10.1098/rsbl.2011.0848. PMC   3259984 . PMID   22158735.

Further reading