Brown Anole
Norops sagrei (Anolis sagrei)
By Christina Miller at Herptiles.net (http://www.herptiles.net)

Last update: Saturday, January 5, 2008.

This caresheet is not to be reproduced in any way without Christina Miller and Herptiles.net as the author and source. It is not to be reproduced and sold for profit, or changed in any way. It may be freely distributed as long as the document remains intact and unchanged.

I. Introduction

Due to its small size, usually reasonable price and commonness in pet stores, the Brown Anole (or the Green Anole, Anolis carolinensis) is often the first reptile pet many of us have. However, because of their availability and cheapness, these lizards are often underappreciated, or seen as "disposable" because of this, and do not get the recognition or respect they deserve. They can be quite interesting and entertaining if kept properly, and as living creatures they deserve to be properly cared for. They may live 5 to 8 years in captivity with good husbandry practices.


II. Taxonomy

Anoles belong to the large, iguanine family Polychrotidae, characterized by lamellae on the underside of their toes, along with sharp claws, allowing them to deftly climb most horizontal and vertical surfaces (even upside-down), including branches, ceilings and glass. Anoles also have very well-developed and often brightly coloured dewlaps, used for communication between other anoles.

The genus classification of Anolis sagrei (Duméril & Bibron 1837) is under debate, as it may be more closely related to anoles in the genus Norops. The genus Anolis is possibly one of the largest in the animal kingdom, with some 250 members. A better resolution of this genus has been the goal of several herpetologists, to better understand the relationships between these lizards (ex: Guyer and Savage, 1986 and 1992). There have been studies using molecular data demonstrating that this species is probably within the genus Norops. (Nicholson, 2002) However, the name Anolis sagrei is still very commonly used, as we still do not have absolute, concrete evidence of the phylogeny of this group.

Usually called the Brown Anole, it is also less commonly known as de la Sagra's Anole, the Bahamian Anole, and the Cuban Anole, the latter two of the four derived from two of the six subspecies. Norops sagrei ordinatus (Cope 1864) is the most commonly seen in pet shops under the name of the Bahamian Anole, a bright red dewlap marks this subspecies. The Cuban Brown Anole is less often seen, N. s. sagrei, (Duméril & Bibron 1837) and has a mustard yellow dewlap. There are also four other subspecies, N. s. greyi (Barbour 1914), N. s. luteosignifer (Garman 1888), N. s. mayensis (Smith & Burger 1949) and N. s. nelsoni (Barbour 1914).

III. Description

It is a robust-bodied lizard, with a small, triangular head with medium-sized brown eyes. They can reach an STL of 13-22cm (5-9"). Body pattern ranges from lines to triangles, colour ranges from pale brown to tan to nearly black. Females may have a noticeable white stripe down center of the back, ending where the tail begins. Males may have a large crest down neck and back, sometimes continuing down the tail, and mature males' patterns usually fade to a uniform tan. Males also have a larger dewlap than females, which, in case of the subspecies, can be either mustard yellow or bright red.

IV. Behaviour

This diurnal species is semi-arboreal, spending most of its time foraging on the ground or on shrubs or tree trunks near the ground. An anole that refuses to climb is probably very ill. They are normally bright, alert and wary.

Like most iguanines, anoles are visually-oriented lizards. They use a series of body movements and displays to communicate with each other, such as head bobs, pushups, and displaying the dewlap. The dewlap is a large, brightly-coloured flap of skin on the throat that extends down to the anole's chest. This skin can be stretched out by an erected rod of cartilage. These displays are used to warn strange lizards that enter the anole's territory, or by males courting females.

This species is generally flighty regarding animals larger than itself (including humans); rarely will you find a specimen that allows it to be held. Typically, if the anole allows itself to be held without trying to escape, it is a very sick lizard.

Like most lizards, anoles can autotomize their tail if they feel threatened. This defense mechanism, called caudal autotomy, occurs as a sort of "last ditch" effort for the lizard to escape a predator. Its tail breaks off, and the severed piece proceeds to twitch for several minutes afterwards (due to excited nerves left in the tail). This is supposed to distract the predator while the lizard escapes. The tail can regenerate after time, however the re-grown portion of the tail will not be the same colour or have the same texture as the original tail. Regenerating a tail takes a lot of energy from the animal, as well- the animal will not grow larger until the tail is complete.

Like most anoles, browns can exhibit some colour change- from tan or light brown to a dark, chocolate brown. This colour change is involuntary, but it is important to understand why it occurs. A happy, healthy Brown Anole is usually light brown or tan, although females seem to have a tendency to be darker than males even when content. They darken when they are stressed or too cool, but an anole that is continually dark is probably very stressed, ill or has no environmental means of warming up to a correct temperature. This colour changing mechanism is caused by layers of coloured cells, called chromatophores, in the skin. Detailed studies of the skin of a close relative, the Green Anole (Anolis carolinensis) have been performed. (Alexander and Fahrenbach, 1969; Taylor and Hadley, 1970) The mechanism in browns is probably similar, although they lack chromatophores that give greens their, well, green colour. Melanophores are dark brown-black pigment cells, and they migrate upwards or downwards to give the animal its darker or lighter colour. Melanophore migration occurs in response to hormones such as melanophore stimulating hormone (MSH) and norepinephrine (a hormone related to stress, among other physiological processes). The bright red dewlap of the Bahamian brown contains many iridophores (iridescent, somewhat reflective chromatophores), a few melanophores and many erythrophores, which are red chromatophores. The yellow dewlap of the Cuban brown would probably contain many xanthophores, which are yellow chromatophores.

V. Diet

These lizards will thrive on a varied diet of invertebrates. Crickets, cockroaches, superworms and mealworms should be part of the diet to provide roughage, and adding soft prey like small hornworms, butterworms, and silk worms adds more nutritional variety. All prey should be gut-loaded on a nutritious diet 24-36 hours before being fed to the lizards. This is to ensure that the prey you are feeding contains a variety of nutrients, as most prey is poorly fed at the pet store. Fatty prey like wax worms are nice supplements, but because of their high fat content they should be fed sparingly. Prey variety is the key to good health. Do not limit your anole's diet to just one or two different types of prey.

Some individuals will also take bits of brightly-coloured fruits and vegetables (as a supplement to their insect diet), such as romaine lettuce, carrot, berries, and fruit baby foods. Slice or shred them into very small pieces (unnecessary for baby food), and place into a small dish where the lizard can easily see and reach it. Place the baby food in a small dish like other vegetables or fruits. Ensure that the dish is kept clean. It is possible to mix powdered calcium supplement into the baby food, and considering the poor calcium content of most vegetation this is a good idea to counteract an imbalance of calcium to phosphorus in the meal. Plant-eating anoles seem to be the exception rather than the rule, and plants should by no means be a large part of the diet, but a small supplement.

Young anoles should have food available daily (preferably confined to a dish so that the prey is easy to find). Adults can be fed every 2-5 days, as much as they will eat in about 10 minutes is a good way to find out how much your lizard will normally take. Remove uneaten food from the enclosure, as invertebrates can chew on sleeping lizards.

Dietary supplement powders are a controversial topic as we are uncertain of exactly how much is needed. We cannot possibly provide the same type of nutrition that these animals have in the wild, so their use is not unfounded. Vitamin and minerals overdoses are possible, so they should be used sparingly, and gut-loading should never be replaced by supplements. Because most invertebrate prey has an inverse calcium to phosphorus ratio, consider dusting most invertebrate prey with calcium powder. Multivitamin and mineral supplements can be used less often. Gravid females should be provided more calcium in their diet to make up for calcium lost to eggshell and yolk production. My personal supplementing schedule for all of my insectivorous herps includes calcium every 1-2 meals, and a multivitamin and mineral supplement every 4-5 meals.


VI. Housing

Size and build: Many older sources suggest that two adult anoles can be kept in a 38 L (10-gallon) aquarium, but this is not ideal as it can be very stressful to the lizards. Anoles are very territorial, so a much larger enclosure would be needed to cohabitate multiple lizards. One anole may be kept in a 38 litre/10 gallon enclosure, but add 11-15 L more (3-5 gallons) for each other individual, and do not house males together. If you are planning on introducing several lizards to the same aquarium, do it at the same time so that they can "decide" on territories; lizards added gradually may be seen as intruders. Remember that a sparsely inhabited enclosure is better than a crowded one. A single anole will be healthier alone than with cagemates.

On a related note, mixing species is not recommended. Particularly, they should not be housed with Green Anoles, Anolis carolinensis. This is a common display in pet stores, but Brown Anoles are a much more aggressive species and tend to stress out greens and outcompete them for food, heat and hides. Wild populations of greens are actually suffering because of introduced browns because of competition of food and predation of Green Anole hatchlings. (Campbell, 2002)

The enclosure may be screen, wooden or glass, as long as humidity and temperature requirements are met. Completely transparent enclosures are discouraged, since these are prey animals and some security should be provided by covering several sides of the enclosure.

If using an aquarium, the lid should not be an aquarium cover intended for fish. Either buy a screen lid to fit the top or make your own. A screen portion is safe to put lights over and allows ventilation. The lid must be too heavy for the lizards to move.

Cage furniture: Vertical climbing space and plenty of plant cover are key with anoles. These lizards live in forest habitats, and this should be simulated in captivity. Branches placed vertically, diagonally and horizontally provide climbing and resting spots. Live or fake plants may be used. Fake plants are less work to maintain than live plants, but live plants provide more humid microhabitats and can help to raise relative humidity.

Tough and hardy plants that appreciate warm, humid conditions like pothos, philodendrons, dracaenae (like the Madagascar dragon tree and corn plant dracaena), hibiscus, some bromeliads, spider plants and sansvierias (snake plants) have been used with success in anole enclosures. All plants to be used in the enclosure should be repotted into a sterile, plain potting soil free of fertilizers, pesticides, vermiculite and perlite (small Styrofoam balls). The entire plant should be rinsed several times in lukewarm water to remove any pesticide residue from the nursery. Inspect the plants before purchase for pests like slugs, aphids and others. Once in the enclosure, maintain the plants according to their appropriate needs.

Substrate: As substrate, plain potting earth is relatively safe, simple and cheap. Be sure to select soil with no additives such as fertilizers, vermiculite or perlite. Appropriate forest soil mixes including soil, woodchips, sand and decomposing leaves are also suitable. Substrate consisting of loose chunks of material such as woodchips, crushed walnut shell and crushed corncob should be avoided, as these are generally unsuitable for lizards for various reasons.

Simple sheet substrates like paper towels or newsprint are suitable for a temporary enclosure (such as a quarantine or hospital cage), however natural substrates that are properly maintained will help raise humidity and preserve a natural atmosphere.

VII. Water

Wild anoles drink from water droplets on vegetation. Water should be misted in the enclosure, on the leaves of the artificial or live plants and enclosure walls at least once a day. A spray bottle or automatic misting equipment will both work equally well.

A water dish is not necessary for drinking, but a wide, shallow water dish can help raise humidity in the enclosure. The dish should be cleaned regularly. These lizards can sometimes learn to drink out of a pool of water, but still mist the enclosure daily to ensure that the lizard is getting enough to drink.


VIII. Heating

XII. Health

Proper husbandry is the key to good health in all reptiles. If you provide good basic care, then you will avoid the vast majority of potential health problems that reptiles can encounter in captivity.

Because Green Anoles are virtually all wild caught, they are undoubtedbly parasitized. The process of being captured is very stressful, and this stress can afflict the immune system and allow any normally harmless parasites to become disease-causing. A fecal exam should be performed by an experienced reptile vet to determine if antiparasitic medications are needed to prevent any parasite-related health problems.

Anorexia is a common problem in captive anoles, and is often attributable to poor environmental conditions (too hot, too cold or too stressful) or a heavy parasite load.

When in doubt about a health issue with your pet, do not hesitate to contact a knowledgeable reptile and amphibian veterinarian. To find a vet in your area, see the directory at the Association of Reptile and Amphibian Veterinarians website (http://www.arav.org).

Glossary:

• Dewlap: A fold of skin on the throat (sometimes extending to chest) found mainly in iguanine lizards, which can usually be extended by a cartilage rod during threat or courtship displays.
• Diurnal: Describes an animal that is naturally active during daylight hours.
• Lamella: A thin, flat structure of tissue. Plural, lamellae.
• STL: "Snout to tail length," the length of the animal from the tip of its snout to the tip of its tail.
• SVL: "Snout to vent length," the length of the animal from the tip of its snout to the vent, i.e. the length of the animal not including the tail.

Sources:

• Alexander, NJ and WH Fahrenbach. 1969. The dermal chromatophores of Anolis carolinensis (Reptilia, Iguanidae). American Journal of Anatomy. 126(1): 41-55.
  
• Bartlett, RD and Bartlett, P. 1997. Lizard Care from A to Z. New York: Barron's Educational Series, Inc.
• Campbell, T. 2002. Institute for Biological Invasions. "The Invader of the Month: The Brown Anole, Anolis sagrei." (http://invasions.bio.utk.edu/invaders/sagrei.html)
  
• Guyer, C and JM Savage. 1986. Cladistic Relationships Among Anoles (Sauria: Iguanidae). Systematic Zoology. 35(4): 509-531.
  
• Guyer, C and JM Savage. 1992. Anole Systematics Revisited. Systematic Biology. 41(1): 89-110.
  
• Kaplan, M. 2003. Anapsid.org. "Anoles." (http://www.anapsid.org/anole.html)
  
• Nicholson, KE. 2002. Phylogenetic analysis and a test of the current infrageneric classification of Norops (beta Anolis). Herpetological Monographs. 16(1): 93-120.
  
• Taylor, JD and ME Hadley. 1969. Chromatophores and color change in the lizard, Anolis carolinensis. 1970. Cell Tissue and Research. 104(2): 282-294.
  
• Under the Leaves: Complete Anole Care. 2004. (http://www.kingsnake.com/anolecare/)