Parson's chameleon (Calumma parsonii) is a large species of chameleon in the family Chamaeleonidae. It is among the largest chameleons in the world and is one of the longest-lived chameleon species. Parson’s chameleon is listed on CITES Appendix II, meaning that trade in this species is regulated. While most chameleon species from Madagascar cannot be legally exported, a limited number of Parson's chameleons can be legally exported each year from their native country.
Male Parson’s chameleons have ridges running from above the eyes to the nose, forming two warty horns. Several color variants are known within the range. This includes "orange eye" aka "white-lipped" (generally considered typical of the nominate subspecies), where the male is relatively small and mainly green or turquoise but with yellow or orange eyelids; "yellow lip" where the male is somewhat larger and mainly green or turquoise, but with a yellow edge to the mouth; "yellow giant" where the male is very large and overall yellowish (strongly marked with dusky when stressed); and "green giant" where the male is overall green. Males of C. p. cristifer are overall green or turquoise. Females of both subspecies are smaller than the males and overall greenish, yellowish, or brownish (often with an orange tinge).
Parson’s chameleons can be found only in isolated pockets of humid primary forest in eastern and northern Madagascar.
Parson’s chameleons live in trees and lead a solitary lifestyle. They are active during the daylight hours and at dusk seek a sheltered place in a tree to rest. Chameleons are adapted for climbing and visual hunting. The use of their prehensile tail offers stability when they are moving or resting while on a branch in the canopy; because of this, their tail is often referred to as a "fifth limb". Chameleons are ambush predators and feed by ballistically projecting their long tongues from their mouths to capture prey located some distance away. Tongue projection occurs at extremely high performance and reaches the prey in as little as 0.07 seconds. Chameleons have many predators but they are unlikely to be able to flee from them and rely on crypsis as their primary defense. Chameleons can change both their colors and their patterns (to varying extents) to resemble their surroundings or disrupt the body outline and remain hidden from a potential enemy's sight. Only if detected, chameleons actively defend themselves. They adopt a defensive body posture, present an attacker with a laterally flattened body to appear larger, warn with an open mouth, and, if needed, utilize feet and jaws to fight back. Color change in chameleons also has other functions such as in social signaling and in reactions to temperature and other conditions.
Parson’s chameleons have an omnivorous diet and feed on various plants, insects, and some small birds.
Parson’s chameleons are polygynous meaning that one male mates with more than one female during the mating season. The breeding season occurs between May and October. In captivity, females of Parson's chameleon lay up to 50 eggs per clutch and the eggs can take up to 2 years to hatch. In one instance, a healthy juvenile hatched after 781 days. The female's reproductive cycle allows for egg laying only once every two years. The hatchlings are independent once they dig themselves out of their underground nest. Once the nest is dug, eggs are laid, and buried, the female's parental obligations are concluded. Parents do not contribute any care towards their young. Reproductive maturity is usually reached at 3 years of age.
The main threat to the Parson's chameleon is the loss of its native habitat due to fragmentation and logging. This species is also susceptible to the pressures posed by both sanctioned and unsanctioned wildlife trade.
The IUCN Red List and other sources don’t provide the number of the Parson’s chameleon total population size. Currently, this species is classified as Near Threatened (NT) on the IUCN Red List, and its numbers today are decreasing.
