Anolis cristatellus

Geographic Range

Crested anoles are native to neotropical areas, such as Puerto Rico (including the islands of Vieques, Culebra) and islands in the Caribbean (Anegada, Tortola, Virgin Gorda, Jost Van Dyke, St. John, and St. Thomas). They are also considered to be an introduced species in Florida, the Dominican Republic, and Costa Rica. It is uncertain exactly when this species was introduced into these areas, although there is some consensus that the crested anole was introduced into La Romana (Dominican Republic) before 1920.

• Biogeographic Regions
• nearctic nearctic
  • introduced introduced
• neotropical neotropical
  • native native

Habitat

This is a perching species that is common in arboreal habitats. Males especially will use the trunks of trees as a way of displaying to other animals. Because they tend to remain close to the ground, they have been called a trunk-ground species. They may also perch on walls and fences, which are usually in more open areas and give a better vantage point for spotting prey or being seen by intruders in their territory. For this reason, crested anoles are commonly found in urban and suburban areas.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• savanna or grassland savanna or grassland
• forest forest

• Other Habitat Features
• urban urban
• suburban suburban

Physical Description

Crested anoles are known to reach lengths of 10 to 20.5 cm (4 to 8 in). Because this species has such a long tail, the SVL (snout-vent length) is usually just 7.5 cm for males and 5.7 cm for females. Females are much smaller than males. Hatchlings of this species are about 5.08 cm (2 in). Males can can vary from a grayish to a light brown color, and may have a crest on their tails. Males also have a dewlap, a flap of skin located under the neck that is able to be extended for use in communication. Dewlaps vary in color from yellow to red and may be lighter or darker depending on habitat moisture conditions. Females are drab and colored similarly to the ground, with a dark-bordered light stripe on their backs. Young males also have this dorsal stripe until they reach maturity. Females lack a tail crest and dewlap. This species has the ability to change color depending on its environment, lighting or mood.

• Other Physical Features
• heterothermic heterothermic

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• ornamentation ornamentation

Development

Little is known about the specific development of crested anoles. Males tend to grow faster than females in most Anolis species. As individuals reach adulthood, this growth rate difference leads to sexual dimorphism. As juveniles, male crested anoles resemble females and their dewlap is not developed. This structure, and the dorsal crest, develops in males over time.

• Development - Life Cycle
• indeterminate growth indeterminate growth

Reproduction

Males will regularly mate with females within their territory. In order to attract a mate, male anoles will approach females and perform a series of displays. These include bobbing the head, pushups, and displaying the dewlap. If the female acknowledges the male's display, she will bob her head in response. When the male mounts the female, she will arch her neck and the male will bite it. He then brings his tail closer to the female's and inserts his hemipene into the female's cloaca. However, females may reject the mating advances of a male before this point and if so, will flee instead of arching their neck.

• Mating System
• polygynous polygynous

Egg production in crested anoles is seasonal, with activity dropping in colder months and during the dry season. Crested anole females lay one or two eggs under logs and rock piles at two-week intervals. In general, when a female anole finds a spot to lay her eggs, she will nudge this spot with her snout. This behavior is then followed by digging with her forelegs. When the has been laid in the hole, the female will push it in further and then cover it with dirt. This species also participates in communal egg-laying, in which multiple females will use the same nest site to lay their eggs. The incubation period is 50 days, on average.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• sexual sexual
• fertilization fertilization
• oviparous oviparous

With the exception of the nutrients present in the egg and digging a hole in which to lay them, crested anoles do not contribute further to the success of their offspring.

• Parental Investment
• no parental involvement
• pre-fertilization
  • provisioning
  • protecting
    • female

Lifespan/Longevity

Little is known about the lifespan of crested anoles in the wild or in captivity. Several other Anolis species, however, have been reported to have average lifespans of about 7 years in captivity. It has been determined that the lifespan of an anole is strongly linked to the number of predators who share their habitat.

Behavior

Crested anoles are diurnal lizards that use perching as a means of warding off other males, attracting females, and foraging for foods such as insects, fruit, frogs, and even other lizards. Generally, crested anoles perch parallel to the tree with their head facing the ground. Although, they can climb higher than 3m, they tend to prefer areas where sunlight is more plentiful, such as fence posts, tree trunks, or the walls of buildings. Males will climb to the top of the trees at night to sleep, while females and younger males stay lower.

This species is extremely territorial. It uses threat displays that resemble pushups and extensions of the dewlap. Head-bobbing is also common in these displays. In most cases the male will make these threat displays from a perching position in their territory. This will alert any other males in the area of their ownership of that territory. These behaviors are also very similar to mating and anti-predator displays. If these displays fail to chase away other males, they will typically fight with each other over territories and access to females.

• Key Behaviors
• arboreal arboreal
• scansorial
• diurnal diurnal
• territorial territorial

Home Range

Adult crested anoles typically defend territories on trees, walls, or shrubs. The adult males usually occupy territories until death. However, young anoles usually move from territory to territory. Adult females occupy much smaller territories and will usually overlap with a male's. Crested anoles show weak orientation skills and will have a difficult time returning to their territory if they are placed outside their realm of familiarity. Though both males and females have homing capabilities, they are much weaker in females.

Communication and Perception

Crested anoles rely heavily on visual cues in order to communicate with one another. Generally, males who defend territories exhibit this behavior. These displays include pushups, extensions of the dewlap, head bobbing, biting, and tail lashing. These behaviors convey one of two meanings, either telling a potential mate that the male is interested, or warning other males that they are intruding into their territory. The dewlap is a very important part of anole species' intraspecific and interspecific communication, as it varies in color across species. This visual cue is very important when defending a territory from a potential threat.

• Communication Channels
• visual visual

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• vibrations vibrations
• chemical chemical

Food Habits

Crested anoles are primarily insectivores, eating prey that range in size from ants to large roaches. They also feed on small fruits, frogs, and even other lizards (including the young of their own species). Crested anoles are foragers and typically scan their environment for food from a perching position on the trunks of trees or the sides of buildings.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• amphibians
• reptiles
• insects
• terrestrial non-insect arthropods

• Plant Foods
• fruit

Predation

In Puerto Rico, crested anoles are primarily eaten by birds, mongoosex, and snakes, including Puerto Rican racers ( Alsophis portoricensis ). However, coqui frogs ( Eleutherodactylus coqui ) and other lizards ( Ameiva exsul ) have also been known to eat anoles in Puerto Rico. In the Lesser Antilles (St. John, Virgin Gorda, Jost Van Dyke, Tortola, and St. Thomas), American kestrels ( Falco sparverius ) and early-eyed thrashers ( Margarops fuscatus ) are the most important bird predators of anoles.

Crested anoles exhibit several different behaviors when confronted by predators. These include expression of the dewlap, body thrashing, biting, tail lashing, head-bobbing, and pushups. These can be used separately or in combination to escape predation.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Crested anoles serve as predators of insects and other small animals and prey to larger carnivorous organisms. In locations where they have been introduced, they have negatively impacted other anoles that were already present in the ecosystem. For example, in La Romana (Dominican Republic), Anolis chlorocyanus are now confined to trees that are slippery, to avoid predation by larger, non-native crested anoles. Cat liver flukes ( Platynosomum concinnum ) use crested anoles as a secondary intermediate host after it has already infected the snail species Subulina octona .

Economic Importance for Humans: Positive

Because crested anoles are mostly insectivores, they are important factors in controlling pest populations in the areas where they coexist with humans. Crested anoles are also becoming more popular as pets.

As an invasive species in many areas, crested anoles have been subject to different types of habitats. Because introduction in a new habitat can lead to the natural selection of traits that may not have been selected for in their native habitat (for example dewlap design), crested anoles have become a popular model organism in evolutionary studies.

• Positive Impacts
• pet trade pet trade
• research and education
• controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of crested anoles on humans.

Conservation Status

At this time, crested anoles have no special conservation status.

Additional Links

Encyclopedia of Life

Contributors

Dylan McDaniel (author), Radford University, Karen Powers (editor), Radford University, Kiersten Newtoff (editor), Radford University, Melissa Whistleman (editor), Radford University, Jeremy Wright (editor), University of Michigan-Ann Arbor.

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