Animal Diversity Web

Diversity

Chamaeleo previously grouped more species and was more diverse than it is today. With more research and studies, old names were resurrected to the genus level. Chamaeleo split into three other genera to narrow down its own morphological traits. Fourteen extant species are now recognized in Chamaeleo with one extinct species. The species best known is Chamaeleo calyptratus, or the veiled chameleon. A few species also have subspecies within them. Chameleons are known for their variety of colors, long protrusible tongue, independently moving eyes, prehensile tail, and zygodactylous feet. Their diet consists of larvae, insects, and some plants. They are stalkers and live in diverse forest habitats. Most are arboreal with a couple species being mostly terrestrial. ("Chamaeleo Laurenti, 1768", 2021; Naish, 2016; Vitt and Caldwell, 2014)

Geographic Range

Most species live in sub-saharan Africa with few species ranging up into northern Africa into southern Europe and also southern Asia, specifically the Middle East, India and Sri Lanka. They inhabit the Ethiopian, Palearctic, and Oriental regions. They are often seen in captivity, most commonly the senegal and veiled chameleons. Habitats range from scrublands to forests up to 8,500 feet in elevation. ("Chamaeleo Laurenti, 1768", 2021)

• Biogeographic Regions
• palearctic
  • native
• oriental
  • native
• ethiopian
  • native

Habitat

Chameleons can be found in tropical rainforests, mountain rainforests, savannas, scrublands, and even crop plantations. Most species are arboreal and live high up in trees or low to the ground in shrubs. A few species can be found on the ground and are mostly terrestrial due to sparse trees or shrubs. Mountain rainforest habitats range up to about 8,500 feet. Tropical rainforests or crop plantations can be found at sea level around the Mediterranean Sea or the Indian Ocean. Savannas and terrestrial chameleons inhabit sub-saharan Africa. ("Chameleon", 2018; "Chameleons: Chamaeleonidae", 2022)

• Habitat Regions
• temperate
• tropical
• terrestrial

• Terrestrial Biomes
• savanna or grassland
• rainforest
• scrub forest

Systematic and Taxonomic History

Previously, Chamaeleo used to be broader and cover more species under its genus. With more studies, it was eventually decided that the genus was just too diverse so it had to be split into different genera. It was then split into Chamaeleo sensu stricto, Calumma, Furcifer, and Bradypodion. These genera, along with Trioceros, are now considered the closest related groups to Chamaeleo. Chamaeleo now only has 14 species within it. (Naish, 2016)

Physical Description

Chameleons are slow moving with independently moving eyes. They have a long, protrusible tongue and usually a prehensile tail. They have zygodactylous feet, which are fusions of two and three digits to form opposable fore and hind limbs. They also possess the ability to change skin coloration. The skin is usually composed of small, juxtaposed scales. Males are generally bigger and more colorful than females. There are, however, a few species where the female is larger than the male. Male size can range from 20cm-61cm in some species. Females can range from 20cm-35cm. Another distinction that some males have is spurs on their hind limbs. Juveniles are normally monochrome, while adults are more colorful. Like other reptiles, chameleons rely on their environment to regulate their temperature and keep them warm. ("Chamaeleo Laurenti, 1768", 2021)

• Other Physical Features
• ectothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger
• male larger
• male more colorful

Development

Via internal fertilization, multiple zygotes are formed within the female. The amniotic eggs gestate in the female for a few weeks before they are laid and buried in soil. After incubation, the eggs hatch and babies emerge as smaller versions of the adults. They grow until they are a mature adult from determinate growth. Unlike other reptiles, chameleons do not have temperature-dependent sex determination. (Vitt and Caldwell, 2014)

• Development - Life Cycle
• neotenic/paedomorphic

Reproduction

Chameleons communicate with their color variations, so females will change their coloring to show that they are ready to mate. Color changes happen for many different reasons so it is often hard to understand what they all mean. The female's color change during mating, however, is distinct and copulations are more frequent when these colors appear. Females will then choose the best looking, most vibrant, and most dominant male to mate with. They are not monogamous. Rather, males and females wander around to different trees to find mates. ("Chameleon", 2018; Cuadrado, 1998)

• Mating System
• polygynandrous (promiscuous)

All species included in this genus are oviparous. Mating season occurs during the warmer months, usually July-September. They can also mate twice a year during wet and dry seasons. Around a month after internal fertilization occurs, females descend to the ground, dig a hole, and lay eggs. A clutch size can range from 10-70 eggs depending on the species. The rest of the incubation is done by the ground, which ranges from a few months to 10 months depending on the species. Juveniles take 5 months to over a year to reach maturity. ("Chameleon", 2018; "Chamaeleo Laurenti, 1768", 2021)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• fertilization
  • internal
• oviparous

There is hardly any parental care provided to the young. The mother carries the eggs for about a month or two, lays them in the ground, then leaves. Babies hatch fully self-sufficient. They intrinsically know how to hunt for themselves. Males of some species may even eat babies that they find. ("Chameleon", 2018; "Chamaeleo Laurenti, 1768", 2021)

• Parental Investment
• no parental involvement

Lifespan/Longevity

The average lifespan of Chamaeleo chameleons is about 3-8 years in the wild. Males typically live longer than females. In captivity, lifespans can be extended with proper care, but average to about 10 years. ("Chamaeleo Laurenti, 1768", 2021)

Behavior

Males tend to be aggressive, territorial, and more solitary towards other males. They use their colorful displays to threaten other males. They may produce sounds like hissing when feeling threatened as well. Females can tolerate each other in closer proximity unless they are receptive or gravid. Chameleons are also slow-moving creatures, grasping foilage and branches with their zygodactylous feet and their prehensile tails, so hunting prey is easier with their long, projectile tongue. They stalk their prey then missile shoot their tongue to capture their food with impeccable accuracy. They are mostly insectivores, but some may eat small vertebrates as well. They are active during the day and sleep throughout the night. Sleeping makes them vulnerable, so they choose a spot where they are well hidden and blend in. ("Chameleon", 2018; "Chamaeleo Laurenti, 1768", 2021)

• Key Behaviors
• arboreal
• scansorial
• diurnal
• motile
• sedentary
• solitary
• territorial

Communication and Perception

Chameleons most commonly communicate by changing their skin pigmentation to show their social status. They may also change their coloration to show red or orange when they are fearful or angry. When they are submissive, they may change their pigment to a more brown or grey color. Females also show a specific coloration when they are receptive or gravid. Bright colors are also used for aggression or higher social statuses. Dull colors are shown when timid and submissive. Eyesight is well developed with independently moving eyes. Depth perception is also very accurate as it aids in prey capture. ("Chameleon", 2018; "Chamaeleo Laurenti, 1768", 2021)

• Communication Channels
• visual

• Perception Channels
• visual

Food Habits

These chameleons are mostly insectivores, but will also eat leaves or sometimes small vertebrates. They mostly feed on insects and invertebrates like locusts, crickets, roaches, worms, slugs, snails, grasshoppers, and flies. Some have been known to eat plant matter and it is believed that they do so for water in the drier months. The larger chameleons are known to prey on small vertebrates like young birds, small rodents, and smaller lizards. They are limited by the width of their throat for how big their prey can be, so body size influences what they eat. Chameleons are very slow-moving, so they have a long tongue that they quickly shoot out with deadly accuracy to capture their prey. ("Chamaeleo Laurenti, 1768", 2021; "Chameleon Diet & Nutritional Information", 2021; "Chameleons: Chamaeleonidae", 2022)

• Primary Diet
• carnivore
  • insectivore

Predation

Chameleons are relatively small, so they are often close to the bottom of the food chain in their ecosystems. They are mostly predated upon by snakes, birds, and sometimes monkeys. The color-changing ability of their skin is their most notable anti-predator adaptation. They can blend into their environment very well, i.e. a chameleon on a branch can change its skin to match the branch or match a leaf and predators can pass by them without having seen them. ("Chameleon", 2022a; "What Animals Eat Chameleons", 2022)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • Boomslang snake (Dispholidus typus)
  • Vine snake (Ahaetulla nasuta)
  • Cuckoo hawk (Aviceda cuculoides)

Ecosystem Roles

Chameleons play an important role in their ecosystems’ food chains. They act as pest control by eating insects. They also serve as prey for higher predators. (Palmer, 2017)

Economic Importance for Humans: Positive

Some species in Chamaeleo are kept as pets. Some do very well in captivity and are bred easily. They are sought after for their colors and temperment. ("Chameleon", 2018)

• Positive Impacts
• pet trade

Economic Importance for Humans: Negative

Because of the attraction to these species as pets, some have been introduced as invasive species. Some species are invasive in states like Florida, Hawaii, and California. They may have been released into the wild when their care needs became too much, and with these areas being hot and humid like their native habitat, they thrived. They do not impact the other species too much since they are insectivores, but they do fill a niche where they are not naturally found. ("Chameleon", 2018)

Conservation Status

Deforestation threatens chameleon populations. No species in g. Chamaeleo, however, are endangered. For the species that are kept as pets, their livelihood is excellent. Conservation efforts may include looking into trade issues, promoting research on their ecology and habitats, and taking measures to preserve their natural habitats. All species but one are on the IUCN Red List as least concern or data deficient. C. monachus is on the Red List as near threatened. ("Chameleon", 2018; "Red List", 2022; "Chameleon", 2022b)

• IUCN Red List [Link]

  Not Evaluated

Contributors

Emma Paul (author), Colorado State University, Audrey Bowman (editor), Colorado State University, Sydney Collins (editor), Colorado State University.

References

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