Crested Anole
Appearance: The crested anole, Anolis cristatellus, is a medium sized lizard (50-75mm SVL in adult males) with a stocky body and relatively long limbs. It is light brown in color and both males and females have varying patterns of dark brown on their backs including mottled coloration, hourglass patterns, and longitudinal stripes. As the common name implies, many individuals have a large tail crest (different from the nuchal crest that can be erected in many species), although there is substantial regional variation in this trait and many individuals have no tail fan at all. Dewlap color is typically two-toned with a yellow center and a thick orange outer edge, although some populations have a more monotone yellow-orange dewlap. Females are smaller than males (30-45mm SVL adults) and have relatively small dewlaps. Post-anal scales are not easily visible in this species, sometimes making it difficult to distinguish females from juvenile males.
Within the native range, this species may be confused with Anolis gundlachi and Anolis cooki. Anolis gundlachi can be distinguished from A. cristatellus by the yellow-tipped chin, blue eye, and solid yellow dewlap, but is otherwise similar in size and appearance. Anolis cooki is more difficult to distinguish from A. cristatellus, but the two only co-occur in the dry forests of southern Puerto Rico. In their non-native range in Florida, this species may be confused with Anolis sagrei, which is slightly smaller in size and has a dewlap that is red-orange in the center with a thin band of yellow on the edge.
Ecology and Habitat: The crested anole is a trunk-ground ecomorph. It typically perches relatively low to the ground (around 2m high or lower) on broad diameter trees. It is often observed in foraging position on tree trunks with head downward as it sits and waits for insect prey to pass by on the ground. It typically eats insects and spiders, but is also known to consume fruits and to prey on small vertebrates, including anoles of their own and other species. This species is rarely seen on the ground except for when moving between perches or catching prey. Like other trunk-ground ecomorphs, A. cristatellus, has relatively long limbs and a stocky build ideal for quickly navigating both arboreal and ground habitat. Anolis cristatellus is commonly found at lower elevations in warm forest habitats and is often restricted to edge or open, disturbed forest habitat at cooler, high elevations. This species is the most common and abundant anole in urban areas in Puerto Rico.
Geographic Range and Biogeography: Anolis cristatellus is endemic to the Puerto Rican bank (Puerto Rico and the Virgin Islands). Its closest relative is A. desechensis, which is found only on the island of Desecheo off the west coast of Puerto Rico. It is also closely related to A. scriptus (found in the Turks and Caicos), A. cooki (found in dry forests in the southwest of Puerto Rico), and A. monensis (found on the island of Mona off the coast of Puerto Rico). Genetic analyses indicate that the ancestor to A. cristatellus (and 12 other Puerto Rican species, which make up the “cristatellus” group) likely colonized Puerto Rico from Hispaniola at least 40 MYA. More recently, A. cristatellus has established in several places outside of its native range, facilitated largely by sale of tropical plants. In particular, it is established in Miami (Florida), Dominica, Costa Rica, Mexico (Yucatan), Trinidad, Saint Martin, and the Dominican Republic.
Research Highlights:
Anolis cristatellus is a great study species for answering so many different questions! As the most wide-ranging Puerto Rican species, it is perfect for comparative studies. Researchers have found no end to the questions they can answer by examining variation within A. cristatellus in different environments and between A. cristatellus and other Puerto Rican species.
For example, with populations in cold, wet, montane habitats to hot, dry, coastal habitats and everything in between, A. cristatellus is perfect for comparing how populations vary in physiological tolerances. Because of this, A. cristatellus has played a major role in our understanding of thermal preferences and tolerances. This follows largely from Ray Huey, Paul Hertz, and colleagues’ foundational work in the 1970’s-80’s, which compared thermal preferences and tolerances of A. cristatellus and established that A. cristatellus is a thermoconformer in some habitats and a thermoregulator in others. Recent work on thermal tolerance in A. cristatellus has made great strides in our understanding of thermal physiology of anoles. For example, researchers have found that thermal tolerance in A. cristatellus can rapidly shift in new environments. Manuel Leal and Alex Gunderson found that in Miami A. cristatellus tolerate much cooler temperatures than populations in Puerto Rico, and Shane Campbell-Staton and Kristin Winchell found that urban populations in Puerto Rico tolerate much hotter temperatures than nearby forest populations.
In addition, because they are widespread in disturbed environments in their native and non-native range, they provide a great opportunity to study rapid contemporary adaptation in response to environmental change. For example, Luisa Otero has found that reproductive patterns vary with habitat disturbance over small geographical scales and Joshua Hall found that embryo survival and development is impacted by urban thermal spikes. Urban environments in particular have received substantial attention, with researchers in Miami examining invasion dynamics and artificial night light use, and researchers in Puerto Rico finding shifts in habitat use, morphology, and performance in urban environments.
Species account author: Kristin Winchell
For more information:
Reptile Database: http://reptile-database.reptarium.cz/species?genus=Anolis&species=cristatellus
Animal Diversity Web: https://animaldiversity.org/accounts/Anolis_cristatellus/
Invasive Species Compendium: https://www.cabi.org/isc/datasheet/93810
- Puerto Rico Herpetology Symposium - September 21, 2023
- Anole Symposium This Fall? - July 14, 2023
- Parallel Urban Adaptation from Phenotype to Genotype in Anolis Lizards - January 20, 2023