Jackson's chameleon (Trioceros jacksonii), also known commonly as Jackson's horned chameleon, the three-horned chameleon, and the Kikuyu three-horned chameleon, is a species of chameleon, a lizard in the family Chamaeleonidae. The species is native to East Africa, and introduced to Hawaii, Florida, and California. There are three recognized subspecies.
Taxonomy
Jackson's chameleon was described by Belgian-British zoologist George Albert Boulenger in 1896.
Etymology
The generic name, Trioceros, is derived from the Greek τρί- (tri-) meaning "three" and κέρας (kéras) meaning "horns". This is in reference to the three horns found on the heads of males.
The specific name, jacksonii, is a Latinized form of the last name of English explorer and ornithologist Frederick John Jackson, who was serving as the first Governor of Kenya at the time of Boulenger's description.
Subspecies
The following three subspecies are recognized as being valid, including the nominate subspecies. In these areas, the rainfall is seasonal but exceeds per year. Day temperatures are typically , and night temperatures are typically . This subspecies has also been introduced to Florida. or instead have traces of the rostral horn (in the subspecies T. j. jacksonii and T. j. merumontanus). The coloring is usually bright green, with some individual animals having traces of blue and yellow, but like all chameleons, it changes color quickly depending on mood, health, and temperature.
Adult males reach a total length (including tail) of up to and females up to , but more typical lengths are .
Ecology
Feeding habits
thumb|Jackson's chameleon climbing a branch at Enchanting Floral Gardens of Kula, Maui, Hawaii
Jackson's chameleon lives primarily on a diet of small insects. It also preys on centipedes, isopods, millipedes, spiders, lizards, small birds, and snails (Achatinella mustelina) in their native habitat.
There is a threat of devastating impact by introduced invasive Jackson's chameleons to native ecosystems in Hawaii, eight to thirty live young are born after a five- to six-month gestation. The subspecies T. j. merumontanus gives birth to five to ten live young.
In captivity
In captivity, Jackson's chameleon requires high humidity, and is in general very needy of colder temperatures during the night. Too much heat, or excessive humidity, can cause eye infections and upper respiratory infections in this species. In captivity, Jackson's chameleon can be expected to live between five and ten years. Jackson's chameleon requires an array of different food options to remain healthy.