Lizards are a diverse group of reptiles that come in a variety of shapes, sizes, and colors. Some lizards are drab and camouflaged to blend in with their environments, while others have vibrant, brilliant colors that stand out. The most colorful and vibrant lizards belong to a group known as anoles. Anoles are small, agile lizards found throughout the Americas and Caribbean islands. They are characterized by the ability to change color, a dewlap under the throat, and enlarged toe pads that help them climb and cling to trees and other surfaces. Of the over 400 species of anole, some of the most spectacularly colored are the knight anoles and day geckos of the Caribbean and Pacific Islands.
Knight Anole
The knight anole (Anolis equestris) is a large, semi-arboreal lizard native to Cuba, Hispaniola, and introduced to Florida. It gets its name from the large, helmet-like crest on the back of its head and neck that is reminiscent of a knight’s helmet. The knight anole is one of the most colorful lizards in the world, displaying an intricate pattern of greens, blues, oranges, and pinks along its body.
Male knight anoles can reach up to 17 inches in length, making them the largest anole species. Females reach about half this size. The most striking feature of the knight anole is its color-changing ability. During mating season, dominant males will turn almost completely turquoise with bright orange dewlaps and blue facial markings to stand out. When not displaying, they are usually shades of brown, gray, or green. The colors are produced by pigment cells under the transparent outer layer of skin. By dispersing or concentrating the pigments, the anoles can rapidly change their appearance.
| Color | Meaning |
|---|---|
| Turquoise blue | Dominant mating display |
| Orange | Reproductive signaling |
| Brown/green | Camouflage |
Knight anoles inhabit trees and shrubs and are most commonly seen basking on branches in the sun. They are territorial and often display to defend their areas or attract mates by exhibiting their bright colors, extending a large pink dewlap, and performing head bobs. These behaviors have earned them the nickname “knight of the trees.”
Day Geckos
Day geckos comprise about 40 species in the genera Phelsuma and Rhoptropella, found on Madagascar and islands in the Indian and Pacific Oceans. They are diurnal, arboreal geckos named for their active habits during the day. Most day gecko species display extremely vibrant green colors often mixed with reds, oranges, yellows, blues, or turquoises. For example, the neon day gecko (Phelsuma klemmeri) from Madagascar has striking bright green and blue colors, while the orange-spotted day gecko (P. guentheri) is bright green with speckles of orange and red.
| Species | Coloration | Range |
|---|---|---|
| Giant day gecko | Green with red spots | Madagascar |
| Gold dust day gecko | Green with yellow dots | Madagascar |
| Electric blue gecko | Bright turquoise | Pacific islands |
These colors serve as camouflage in their tropical forest environments as well as social signaling. Brighter males often attract more mates. Day geckos are highly territorial and communicate both with striking visual displays of color and patterns of body movements. Many species also vocalize through various chirps and squeaks. Their vibrant colors and diurnal activity make day geckos popular display animals.
Color Production
The brilliant, vivid colors of anoles and day geckos are created through a combination of structural and pigment coloration. Iridophores are special reflective cells that produce iridescent structural colors through the physical interaction of light with transparent crystals and plates in the skin. Iridophores create the greens, blues, and turquoises seen on many lizard species.
Pigment cells called chromatophores are responsible for the reds, oranges, yellows, browns, and melanin blacks. Xanthophores contain yellow pigments, erythrophores red pigments, and melanophores black pigments. By dispersing and aggregating their pigments, the densities of these chromatophore cells can be rapidly changed, allowing anoles and day geckos to shift their colors and patterns.
Conclusion
The knight anole and day geckos showcase the amazing diversity and beauty of coloration in lizards. Their intricate patterns and brilliant displays are used for camouflage, communication, and attracting mates. Structural light reflection off iridophores and pigment production by chromatophores allow these lizards to dynamically change their vibrant colors. Knight anoles and day geckos have beautifully adapted to life in the trees and forests through the selective evolution of their visual displays. Their striking appearance makes them some of the most colorful and visually impressive lizards in the world.
